WO2025227069A1

WO2025227069A1 - A flush system for particulate metering into fluid streams

Info

Publication number: WO2025227069A1
Application number: PCT/US2025/026436
Authority: WO
Inventors: Joshua S. VANDER HEIDEN; Greg J. DeGrave; Stephen A. Marrano; Dwayne J. JACKSON; Dustin Smith
Original assignee: Kimberly Clark Worldwide Inc; Kimberly Clark Corp
Current assignee: Kimberly Clark Worldwide Inc; Kimberly Clark Corp
Priority date: 2024-04-26
Filing date: 2025-04-25
Publication date: 2025-10-30
Anticipated expiration: 2026-10-26

Abstract

A flush system includes a particle inlet conduit configured for receiving a flow of particles. An outlet conduit is disposed downstream of the particle inlet conduit and configured for receiving the flow of particles from the particle inlet conduit. A fluid inlet plenum is disposed around the outlet conduit and configured for directing a plurality of fluid flows into the outlet conduit.

Description

A FLUSH SYSTEM FOR PARTICULATE METERING INTO FLUID STREAMS

BACKGROUND

Personal care products, such as diapers, diaper pants, training pants, adult incontinence products, and feminine care products, can include a variety of substrates. For example, a diaper can include an absorbent structure, nonwoven materials, and films. Similarly, facial tissues, wipes, and wipers can also include various substrates. Some of the substrates in these products can include natural and/or synthetic fibers. In some products, some substrates can also include different types of components to provide additional functionality to the substrate and/or the end product itself.

For example, one such component that may be desirable to add to a substrate includes a superabsorbent material (SAM). SAM can be configured in the form of a particle or a fiber and is commonly utilized in substrates for increased absorbent capacity. Absorbent systems of personal care absorbent products, such as a diaper, often include SAM. Processes exist for forming a substrate with SAM, including utilizing forming chambers to mix SAM particles or fibers with cellulosic fibers to form an absorbent core. These processes are generally completed in a dry environment, as SAM can be difficult to process when wet due to increase in volume from absorption of fluid and gelling, among other potential drawbacks. However, alternative substrate forming processes can employ fluids, such as liquids, to create substrates providing various other characteristics and efficiencies in manufacturing and performance of such substrates.

Thus, there exists a need to develop methods and apparatuses for introducing a component into a fluid supply for forming substrates. There also exists a need to develop methods and apparatuses for forming substrates including components.

SUMMARY

In general, the present disclosure is directed a flush system. The flush system can facilitate introduction of particles into a liquid stream. The flush system may include features for limiting or preventing particle collection or clumping due contact with the liquid. The flush system may include a particle inlet conduit that receives particles from a particle meter. An outlet conduit is disposed downstream of the particle inlet conduit. The outlet conduit receives the particles from the particle inlet conduit. A fluid inlet plenum is disposed around the particle inlet conduit. The fluid inlet plenum directs fluid flows into the outlet conduit. The fluid flows can flow over a surface of the outlet conduit and limit or prevent contact of the particles against the surface of the outlet conduit. Moreover, the fluid flows can flush the particles off the surface of the outlet conduit into the liquid stream. In example embodiments, an air inlet plenum may also be disposed around the particle inlet conduit and may direct air flows into the particle inlet conduit. The air flows can facilitate dispersion and/or fluidization of the particles within the particle inlet conduit. Moreover, the air flows can be controlled to regulate air bleed into the liquid stream.

In example embodiments, the flush system may be disposed downstream of a particle meter and upstream of an eductor on a particle flow path between the particle meter and the eductor. The flush system can facilitate introduction of superabsorbent material into a flow of foam to a headbox. As an example, the superabsorbent material can swell and gel together after contact with foam at the eductor. The flush system can limit or prevent clumps of damp superabsorbent material from clogging the educator such that superabsorbent material can continue to entrain with the foam at the eductor.

In one example embodiment, a foam forming system includes a particle meter configured for supplying a flow of particles, an eductor configured for directing the flow of particles into a flow of foam, and a flush system disposed downstream of the particle meter and upstream of the eductor on a particle flow path between the particle meter and the eductor. The flush system includes a particle inlet conduit configured for receiving the flow of particles from the particle meter, a particle inlet conduit configured for receiving the flow of particles from the particle meter, an outlet conduit disposed downstream of the particle inlet conduit and configured for receiving the flow of particles from the particle inlet conduit, and a fluid inlet plenum disposed around the outlet conduit and configured for directing a plurality of fluid flows into the outlet conduit

In another example embodiment, a flush system includes a particle inlet conduit configured for receiving a flow of particles. An air inlet plenum is disposed around the particle inlet conduit and configured for directing a plurality of air flows into the particle inlet conduit. An outlet conduit disposed downstream of the particle inlet conduit and configured for receiving a combined flow of air and particles from the particle inlet conduit. A fluid inlet plenum is disposed around the outlet conduit and configured for directing a plurality of fluid flows into the outlet conduit.

In another example embodiment, a flush system includes a particle inlet conduit configured for receiving a flow of particles. An outlet conduit is disposed downstream of the particle inlet conduit and configured for receiving the flow of particles from the particle inlet conduit. A fluid inlet plenum is disposed around the outlet conduit and configured for directing fluid into the outlet conduit such that the fluid coats a surface of the outlet conduit with liquid from the fluid.

These and other features, aspects and advantages of the present disclosure will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present disclosure, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

FIG. 1 is a process schematic view of a system for introducing a component into a fluid supply and forming a substrate including a component according to an example embodiment of the present subject matter.

FIG. 2 is a detailed schematic view of a component feed system of the example system of FIG. 1 . FIG. 3 is a cross-section of a mixing junction and outlet conduit of the example system of FIG. 2.

FIG. 4 is a schematic view of a component feed system according to an example embodiment of the present subject matter.

FIG. 5 is a section view of a flush system according to an example embodiment of the present subject matter.

FIG. 6 is a model view of fluid flow through the example flush system of FIG. 5.

FIG. 7 is a flowchart of a method for introducing a component into a fluid supply and forming a substrate according to an example embodiment of the present subject matter.

FIG. 8 is a section view of a flush system according to another example embodiment of the present subject matter.

Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.

DETAILED DESCRIPTION

The present disclosure is generally directed a flush system that can facilitate introduction of particles into a liquid stream. For instance, the flush system can facilitate introduction of superabsorbent material into a flow of foam to a headbox via an eductor. However, while described in greater detail below in the context of superabsorbent material, it will be understood that the flush system can also be used with other particles, such as fibers, pigments, thermally expandable microspheres, foam particles, etc.

In foam forming processes, superabsorbent material may be added to a pressurized headbox supply flow immediately upstream of the headbox via an eductor or jet pump, which can utilize the Venturi effect to generate low pressure (also referred to herein as a "vacuum”) at an inlet port for the superabsorbent material. The combined slurry of superabsorbent material and foam may be mixed and subsequently formed into a multi-layered web. Because the eductor generates the vacuum during operation, the eductor may be disposed within a sealed system to control the amount of air that bleeds into the combined slurry of superabsorbent material and foam. Thus, the vacuum can slowly reduce pressure of the sealed system while the eductor evacuates air from the sealed system until the sealed system reaches equilibrium pressure and stabilizes. To prevent process upsets, a liquid, such as air or water, may flow into the sealed system at a precise rate to control the vacuum level in the sealed system to a targeted value below a critical value In example embodiments, a flush system may be disposed downstream of a particle metering device and upstream of the eductor. The flush system may control the eductor-generated vacuum level within the sealed system. For example, an air inlet plenum may be disposed around a particle inlet conduit and may direct air flows into the particle inlet conduit. The air flows may be regulated to control the vacuum level within the sealed system. Moreover, the air may bleed into the flush system and create a constant pressure air header, e.g., which may surround the particle inlet conduit. It will be understood that the flush system may not include the air inlet plenum in some example embodiments. Thus, e.g., air may bleed into the flush system via other openings and/or passages.

In example embodiments, a flush system may control a wet-dry interface between the superabsorbent material and the foam. The superabsorbent material may enter the flush system at the particle inlet conduit from the particle metering device, and the superabsorbent material may flow through the flush system and exit through an outlet conduit. A fluid inlet plenum is disposed around the outlet conduit and is configured for directing fluid flows, such as water, surfactant water, or foam, into the outlet conduit. The fluid flows may flow over and/or coat the outlet conduit to limit or prevent superabsorbent material clogging. As the foam forming system runs, foam from the eductor can splash into an area where the superabsorbent material is metered into the foam. The liquid in the foam can cause the superabsorbent material stick on a side of a superabsorbent material inlet port at the eductor, swell, and bridge across the superabsorbent material. The clogged superabsorbent material can back up into other portions of the feeding system and/or other problems. By limiting or avoiding such clogging, the flush system may advantageously facilitate stable and continuous operation of the foam forming system, e.g., without costly time-intensive clean-up processes to clear superabsorbent material clogs. As noted above, fluid flows from the fluid inlet plenum may flow over and/or coat the outlet conduit to limit or prevent superabsorbent material clogging. Moreover, the liquid(s) in the fluid flows may form a constant pressure header, e.g., which may surround the particle inlet conduit. The fluid flows may continually flush and clean any superabsorbent material that sticks to the outlet conduit in order to limit or prevent the system interruptions described above.

Additional aspects of such flush systems are described in more detail below.

The following description should be read with reference to the drawings in which similar elements in different drawings are numbered the same. The description and the drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the disclosure.

Although some suitable dimensions, ranges and/or values pertaining to various components, features and/or specifications are disclosed, one of skill in the art, incited by the present disclosure, would understand desired dimensions, ranges and/or values may deviate from those expressly disclosed.

When introducing elements of the present disclosure or the preferred embodiment(s) thereof, the articles “a", "an”, “the” and “said” are intended to mean that there are one or more of the elements. As used herein, the terms “includes" and “including” are intended to be inclusive in a manner similar to the term “comprising.” Similarly, the term “or” is generally intended to be inclusive (i.e. , “A or B” is intended to mean “A or B or both”). Approximating language, as used herein throughout the specification and claims, is applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about,” “approximately,” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. For example, the approximating language may refer to being within a ten percent (10%) margin.

Each example is provided by way of explanation and is not meant as a limitation. For example, features illustrated or described as part of one embodiment or figure can be used on another embodiment or figure to yield yet another embodiment. It is intended that the present disclosure include such modifications and variations.

Many modifications and variations of the present disclosure can be made without departing from the spirit and scope thereof. Therefore, the exemplary embodiments described above should not be used to limit the scope of the invention.

Definitions:

Within the context of this specification, each term or phrase below will include the following meaning or meanings. Additional terms are defined elsewhere in the specification. As used herein, the term “foam formed product” means a product formed from a suspension including a mixture of a solid, a liquid, and dispersed gas bubbles.

As used herein, the term “foam forming process” means a process for manufacturing a product involving a suspension including a mixture of a solid, a liquid, and dispersed gas bubbles.

As used herein, the term “foaming fluid” means any one or more known fluids compatible with the other components in the foam forming process. Suitable foaming fluids include, but are not limited to, water.

As used herein, the term “foam half life” means the time elapsed until the half of the initial frothed foam mass reverts to liquid water.

As used herein, the term “layer” refers to a structure that provides an area of a substrate in a z-direction of the substrate that is comprised of similar components and structure.

As used herein, the term "nonwoven web" means a web having a structure of individual fibers or threads which are interlaid, but not in an identifiable manner as in a knitted web.

As used herein, unless expressly indicated otherwise, when used in relation to material compositions the terms "percent", “%”, "weight percent", or "percent by weight" each refer to the quantity by weight of a component as a percentage of the total except as whether expressly noted otherwise.

The term “personal care absorbent article” refers herein to an article intended and/or adapted to be placed against or in proximity to the body (i.e., contiguous with the body) of the wearer to absorb and contain various liquid, solid, and semi-solid exudates discharged from the body. Examples include, but are not limited to, diapers, diaper pants, training pants, youth pants, swim pants, feminine hygiene products, including, but not limited to, menstrual pads or pants, incontinence products, medical garments, surgical pads and bandages, and so forth.

The term "ply" refers to a discrete layer within a multi-layered product wherein individual plies may be arranged in juxtaposition to each other.

The term “plied” or “bonded” or “coupled” refers herein to the joining, adhering, connecting, attaching, or the like, of two elements Two elements will be considered plied, bonded or coupled together when they are joined, adhered, connected, attached, or the like, directly to one another or indirectly to one another, such as when each is directly bonded to intermediate elements. The plying, bonding or coupling of one element to another can occur via continuous or intermittent bonds.

The term "superabsorbent material" as used herein refers to water-swellable, water-insoluble organic or inorganic materials including superabsorbent polymers and superabsorbent polymer compositions capable, under the most favorable conditions, of absorbing at least about ten (10) times their weight, or at least about fifteen (15) times their weight, or at least about twenty-five (25) times their weight in an aqueous solution containing nine-tenths weight percent (0.9%) sodium chloride.

These terms may be defined with additional language in the remaining portions of the specification.

Absorbent Article:

In one example embodiment, the present disclosure relates to a method and apparatus 10 that may form a substrate 12. FIG. 1 provides a schematic of an exemplary apparatus 10 that may be used as part of a foam forming process to manufacture a substrate 12 that is a foam formed product. The apparatus 10 may include a tank 14 configured for holding a fluid supply 16. In some example embodiments, the fluid supply 16 may be a foam. The fluid supply 16 may include a fluid provided by a supply of fluid 18. In some example embodiments, the fluid supply 16 may include a plurality fibers provided by a supply of fibers 20; however, in other example embodiments, the fluid supply 16 may be free from a plurality of fibers. The fluid supply 16 may also include a surfactant provided by a supply of surfactant 22. In some example embodiments, the tank 14 may include a mixer 24, as will be discussed in more detail below. The mixer 24 may mix (e.g., agitate) the fluid supply 16 to mix the fluid, fibers (if present), and surfactant with air, or some other gas, to create a foam. The mixer 24 may also mix the foam with fibers (if present) to create a foam suspension of fibers in which the foam holds and separates the fibers to facilitate a distribution of the fibers within the foam (e g., as an artifact of the mixing process in the tank 14). Uniform fiber distribution can promote desirable substrate 12 including, for example, strength and the visual appearance of quality.

For the tank 14, the fluid supply 16 may be acted upon to form a foam. In some example embodiments, the foaming fluid and other components are acted upon so as to form a porous foam having an air content greater than about fifty percent (50%) by volume and desirably an air content greater than about sixty percent (60%) by volume. In certain example aspects, the highly-expanded foam is formed having an air content of between about sixty percent (60%) and about ninety-five percent (95%) and in further example aspects between about sixty-five percent (65%) and about eighty-five percent (85%). In certain example embodiments, the foam may be acted upon to introduce air bubbles such that the ratio of expansion (volume of air to other components in the expanded stable foam) is greater than 1 :1 and in certain embodiments the ratio of air to other components may be between about 1.1 :1 and about 20:1 or between about 1.2:1 and about 15:1 or between about 1.5:1 and about 10:1 or even between about 2:1 and about 5:1 .

The foam may be generated by one or more means known in the art. Examples of suitable methods include, without limitation, aggressive mechanical agitation such as by mixers 24, injection of compressed air, and so forth. Mixing the components through the use of a high-shear, high-speed mixer is particularly well suited for use in the formation of the desired highly-porous foams. Various high-shear mixers are known in the art and believed suitable for use with the present disclosure. High- shear mixers typically employ a tank holding the foam precursor and/or one or more pipes through which the foam precursor is directed. The high-shear mixers may use a series of screens and/or rotors to work the precursor and cause aggressive mixing of the components and air. In a particular example embodiment, the tank 14 is provided having therein one or more rotors or impellers and associated stators. The rotors or impellors are rotated at high speeds in order to cause flow and shear. Air may, for example, be introduced into the tank at various positions or simply drawn in by the action of the mixers 24. While the specific mixer design may influence the speeds necessary to achieve the desired mixing and shear, in certain embodiments suitable rotor speeds may be greater than about five hundred rotations per minute (500 rpm) and, for example, be between about one thousand rotations per minute (1000 rpm) and about six thousand rotations per minute (6000 rpm) or between about two thousand rotations per minute (2000 rpm) and about four thousand (4000 rpm). In certain example embodiments, with respect to rotor based high-shear mixers, the mixer(s) 24 may be run with the foam until the disappearance of the vortex in the foam or a sufficient volume increase is achieved.

In addition, it is noted the foaming process may be accomplished in a single foam generation step or in sequential foam generation steps for the tank 14. For example, in one embodiment, all of the components of the fluid supply 16 in the tank 14 (e.g., the supply of the fluid 18, fibers 20, and surfactant 22) may be mixed together to form a slurry from which a foam is formed for supply to a headbox 80. Alternatively, one or more of the individual components may be added to the foaming fluid, an initial mixture formed (e.g. a dispersion or foam), after which the remaining components may be added to the initially foamed slurry and then all of the components acted upon to form the final foam. In this regard, the fluid 18 and surfactant 22 may be initially mixed and acted upon to form an initial foam prior to the addition of any solids. Fibers, if desired, may then be added to the water/surfactant foam and then further acted upon to form the final foam. As a further alternative, the fluid 18 and fibers 20, such as a high density cellulose pulp sheet, may be aggressively mixed at a higher consistency to form an initial dispersion after which the foaming surfactant, additional water and other components, such as synthetic fibers, are added to form a second mixture which is then mixed and acted upon to form the foam.

The foam density of the foam forming the fluid supply 16 in the tank 14 may vary depending upon the particular application and various factors, such as the fiber stock used. In some implementations, for example, the foam density of the foam may be greater than about one hundred grams per liter (100 g/L), such as greater than about two hundred and fifty grams per liter (250 g/L), such as greater than about three hundred grams per liter (300 g/L). The foam density is generally less than about eight hundred grams per liter (800 g/L), such as less than about five hundred grams per liter (500 g/L), such as less than about four hundred grams per liter (400 g/L), such as less than about three hundred and fifty grams per liter (350 g/L). In some implementations, for example, a lower density foam is used having a foam density of generally less than about three hundred and fifty grams per liter (350 g/L), such as less than about three hundred and forty grams per liter (340 g/L), such as less than about three hundred and thirty grams per liter (330 g/L).

In some example embodiments, the apparatus 10 may also include a pump 36. The pump 36 may be in fluid communication with the fluid supply 16 and may be configured for pumping the fluid supply 16 to transfer the fluid supply 16. In some example embodiments, the pump 36 may be a progressive cavity pump or a centrifugal pump, however, it is contemplated that other suitable types of pumps may be used.

As depicted in FIGS. 1 and 2, the apparatus 10 may also include a component feed system 40. The component feed system 40 may include a component supply area 42 for receiving a supply of a component 44 as shown in the partial cut-away portion of the component supply area 42 illustrated in FIG. 2. The component feed system 40 may also include an outlet conduit 46. The outlet conduit 46 may be circular in cross-sectional shape, or may be configured in a rectangular fashion such as to form a slot. The component feed system 40 may also include a hopper 48. The hopper 48 may be coupled to the component supply area 42 and may be utilized for refiling the supply of the component 44 to the component supply area 42.

In some example embodiments, the component feed system 40 may include a bulk solids pump. Some examples of bulk solids pumps that may be used herein may include systems that utilize screws/augers, belts, vibratory trays, rotating discs, or other known systems for handling and discharging the supply of the component 44. Other types of feeders may be used for the component feed system 40, such as, for example, an ingredient feeder, such as those manufactured by Christy Machine & Conveyor, Fremont, Ohio. The component feed system 40 may also be configured as a conveyor system in some example embodiments.

The component feed system 40 may also include a fluid control system 50. The fluid control system 50 may be configured to control the gas entrainment into the fluid supply into which the supply of the component 44 is being placed. In some example embodiments, the fluid control system 50 may include a housing 52. The housing 52 may form a pressurized seal volume around the component feed system 40. In other example embodiments, the fluid control system 50 may be formed as an integral part to the structure component feed system 40 itself, such that a separate housing 52 surrounding the component feed system 40 may not be required. As depicted in FIGS. 1 and 2, the fluid control system 50 may also include a bleed orifice 54 in some example embodiments.

The supply of the component 44 may be in the form of a particulate and/or a fiber. In one example embodiment as described herein, the supply of the component 44 may be superabsorbent material (SAM) in particulate form. In some example embodiments, the superabsorbent material may be in the form of a fiber. Of course, other types of components, as described further below, are also contemplated as being utilized in the apparatus 10 and methods as described herein. The component feed system 40 as described herein may be particularly beneficial for a supply of component 44 that is most suitably maintained in a dry environment with minimal of exposure to fluid or foam utilized in the apparatus 10 and methods described herein.

Referring to FIGS. 1-3, in some example embodiments, the apparatus 10 and methods described herein may include a mixing junction 56. In preferred example embodiments, the mixing junction 56 may be an eductor. The mixing junction 56 may be in fluid communication with the outlet conduit 46 of the component feed system 40 and in fluid communication with the fluid supply 16. As depicted in FIG. 3, the mixing junction 56 may include a first inlet 60 and a second inlet 62. The first inlet 60 may be in fluid communication with the supply of the component 44 via the outlet conduit 46. The second inlet 62 may be in fluid communication with the fluid supply 16. The mixing junction 56 may also include a discharge 64.

In preferred example embodiments, the mixing junction 56 may be configured as a co-axial eductor. For example, in a preferred example embodiment, the mixing junction 56 may be configured such that the first inlet axis 66 of the first inlet 60 of the mixing junction 56 is co-axial with the outlet axis 68 of outlet conduit 46 that provides the supply of the component 44. The mixing junction 56 may also be configured such that the discharge axis 70 of the discharge 64 is co-axial with the outlet axis 68 of the outlet conduit 46. As such, the mixing junction 56 may be configured such that the first inlet axis 66 of the first inlet 60 may be co-axial with the discharge axis 70 of the discharge 64 of the mixing junction 56. The second inlet 62 providing the fluid supply 16 to the mixing junction 56 may be set up to enter the mixing junction 56 on a side of the mixing junction 56. This configuration of having the supply of the component 44 be delivered in the first inlet 60 in a co-axial fashion to the discharge axis 70, rather than having the fluid supply 16 entering at the first inlet 60, is opposite of most eductor configurations that are mixing a fluid supply and a component using a motive force of the fluid supply, but provides advantages to the mixing junction 56 as described herein. When configured as an eductor, the mixing junction 56 may mix the supply of the component 44 from the component feed system 40 with the fluid supply 16. By transferring the fluid supply 16 into the mixing junction 56 at the second inlet 62 and through the mixing junction 56, the fluid supply 16 provides a motive pressure to the supply of the component 44. The motive pressure can create a vacuum on the supply of the component 44 and the component feed system 40 to help draw the supply of the component 44 to mix and be entrained in the fluid supply 16. In some example embodiments, the motive pressure can create a vacuum on the supply of the component 44 of less than 1 ,5in Hg, however, in other embodiments, the motive pressure could create a vacuum on the supply of the component 44 of 5in. Hg or more, or 10in Hg or more.

The fluid control system 50 can help manage proper distribution and entrainment of the supply of the component 44 to the fluid supply 16 and can help control entrainment of fluid within the fluid supply 16 downstream of the component feed system 40. For example, if there was no housing 52 surrounding the component feed system 40, additional fluid (e.g., surrounding gas, such as air) may be entrained into the fluid supply 16 as the supply of the component 44 is metered into the fluid supply 16. It may also be the case when the fluid supply 16 creates a motive pressure on the component feed system 40, the vacuum pulling on the supply of the component 44 may cause additional air to be entrained in the fluid supply 16. In some circumstances, entraining additional air in the fluid supply 16 may be desired, however, in other circumstances, it may be desirable to control the gas content of the fluid supply 16 while inputting the supply of the component 44 to the fluid supply 16 at mixing junction 56. For example, in some circumstances where the fluid supply 16 is a foam, the amount of gas content in the foam may be desired to be kept relatively fixed as the foam passes through the mixing junction 56. Thus, the fluid control system 50 may help control the pressure on and the gas flow through the component feed system 40 to help prevent or at least control the amount of gas being entrained in the fluid supply 16 when the supply of the component 44 is being mixed with the fluid supply 16, and can help counteract the motive pressure on the supply of the component 44 and the component feed system 40 created by the fluid supply 16.

In some example embodiments, the fluid control system 50 may include sealing off the component feed system 40. For example, as discussed above, the fluid control system 50 may include a housing 52 to provide a seal on the component feed system 40. Sealing the component feed system 40 can help to prevent additional air entrainment in the fluid supply 16 when the supply of the component 44 is introduced into the fluid supply 16 in the mixing junction 56.

However, in some example embodiments, it may be beneficial to also include additional capability to the fluid control system 50. For example, in some example embodiments, the fluid control system 50 may include a bleed orifice 54. The bleed orifice 54 may be configured to bleed-in fluid flow, such as atmospheric air flow, to provide additional fluid flow control of the component feed system 40. The bleed orifice 54 may bleed in gas flow (e.g., air flow) inside the housing 52 to help control the air flow and pressure within the housing 52 surrounding the component feed system 40. It has been discovered that by providing a bleed-in orifice 54 to provide some bleed-in of atmospheric air flow to the component feed system 40, back-splashing of the fluid supply 16 in the mixing junction 56 can be reduced or eliminated. Reducing back-splashing of the fluid supply 16 in the mixing junction 56 can help prevent the component feed system 40 from becoming clogged or needing to be cleaned, especially where the component feed system 40 may be delivering a dry particulate, such as superabsorbent material. Under other process conditions, it may be desirable to completely seal the component feed system 40 for similar reasons.

Additionally or alternatively, the fluid control system 50 may be configured to provide additional gas flow (e.g., air flow) and/or positive pressure to prevent back-filling of the component feed system 40 in some circumstances, such as if a downstream obstruction occurs in the apparatus 10 beyond the mixing junction 56. In such a case of an obstruction creating an increased pressure, the fluid supply 16 may have a desire to back-fill the component feed system 40. Back-filling of fluid into the component feed system 40 can be detrimental to processing, especially where the supply of the component 44 is a dry component, such as superabsorbent material. A fluid control system 50 configured to be able to provide positive pressure to the component feed system 40 can help prevent such back-filling of the component feed system 40.

It is also contemplated that other additional aspects of a fluid control system 50 could be utilized to maintain the gas flow and pressure to a suitable level for the component feed system 40, including, but not limited to, supplying vacuum to the component feed system 40 in addition to or alternative to the air bleed-in at the bleed orifice 54 and/or the positive pressure described above.

As depicted in FIG. 3, in some example embodiments, the mixing junction 56 may also include a venturi section 72. The venturi section 72 may be a necked region of the mixing junction 56 that can increase the velocity of the fluid supply 16 passing through the venturi section 72, and thus, can increase the vacuum pressure created by the fluid supply 16 on the supply of the component 44 in the component feed system 40 and can help entrain the supply of the component 44 within the fluid supply 16. In some example embodiments, the distal end 74 of the outlet conduit 46 providing the supply of the component 44 to the mixing junction 56 may be disposed in the venturi section 72. The location of the distal end 74 of the outlet conduit 46 may be adjusted within the venturi section 72 as one way to control both the pressure of the fluid supply 16 as it is discharged from the mixing junction 56 and the component feed system 40.

The mixing junction 56 may also provide pressure control on the transfer of the fluid supply 16 including the component 44 as the fluid supply 16 exits the discharge 64 of the mixing junction 56 as compared to when the fluid supply 16 enters the mixing junction 56. The fluid supply 16 may be transferred at a second fluid pressure prior to the mixing junction 56. The fluid supply 16 including the component from the supply of the component 44 may exit the discharge 64 of the mixing junction 56 at a discharge pressure. The pressure difference between the second fluid pressure prior to the mixing junction 56 and the discharge pressure may be controlled. In some example embodiments, this pressure difference may be controlled by varying the flow rate of the fluid supply 16. In some example embodiments, this pressure difference may be controlled by the location of the distal end 74 of the outlet conduit 46 in the venturi section 72 of the mixing junction 56. For example, if the distal end 74 of the outlet conduit 46 is moved further into the venturi section 72, the area for the fluid supply 16 to flow through the venturi section 72 is reduced, and thus, the supply pressure of the fluid supply 16 is increased. If the distal end 74 of the outlet conduit 46 is moved further out of the venturi section 72 (i.e., back towards the component feed system 40), the area for the fluid supply 16 to flow through the venturi section 72 is increased, and thus, the supply pressure of the fluid supply 16 entering the mixing junction 56 is decreased as is the vacuum level on the component feed system 40. In some example embodiments, it is preferable to control the pressure difference between the second fluid pressure prior to the mixing junction 56 and the discharge pressure to be less than or equal to twenty-five pounds per square inch (25 psi), or more preferably, less than twenty pounds per square inch (20 psi), or less than fifteen pounds per square inch (15 psi), or less than ten pounds per square inch (10 psi), or less than five pounds per square inch (5 psi).

Another feature of the mixing junction 56 that can create enhanced mixing and transfer of the supply of the component 44 into the fluid supply 16 in the mixing junction 56 may be that the second inlet 62 providing the fluid supply 16 is upstream of the distal end 74 of the outlet conduit 46 that provides the supply of the component 44 from the component feed system 40 to mixing junction 56. With such a configuration, the fluid supply 16 may enter the mixing junction 56 upstream of the supply of the component 44 to prevent any of the supply of the component 44 from engaging or sticking on an internal surface of the mixing junction 56. Thus, in the example embodiment depicted in FIG. 3, the coaxial nature of the outlet axis 68 of the outlet conduit 46 and the discharge axis 70 of the mixing junction 56 and the upstream entry of the fluid supply 16 into the mixing junction 56 may create an annular-shaped fluid protection around the entry of the supply of the component 44 as the component 44 is entrained in the fluid supply 16 in the mixing junction 56.

It is to be noted that while a single outlet conduit 46 of the component feed system 40 and a single mixing junction 56 is illustrated in FIGS. 1-3, it is contemplated that the outlet conduit 46 may be split into two or more conduits to feed two or more mixing junctions 56 for mixing the supply of the component 44 with the fluid supply 16. In such a configuration, the fluid supply 16 may include as many conduits as there are mixing junctions 56. By having more than one outlet conduit 46 and more than one mixing junction 56 to mix the supply of the component 44 with the fluid supply 16, a greater flow rate of the fluid supply 16 including the component from the supply of the component 44 can be achieved.

In some example embodiments, it is also contemplated that the mixing junction 56 may be an eductor of different configuration other than a co-axial eductor as described above. For example, it is contemplated that the mixing junction 56 may be an eductor that is shaped as a slot eductor.

The fluid supply 16 with the entrained component 44 from the mixing junction 56 may be supplied to a headbox 80. In some example embodiments, there can be a separation between the discharge 64 of the mixing junction 56 and the headbox 80, as depicted in FIG. 3. However, in other example embodiments, the discharge 64 of the mixing junction 56 may be integral with the headbox 80.

Flush System:

A flush system 100 according to an example embodiment of the present subject matter is described in greater detail below. The flush system 100 may be used in or with any suitable system to assist with limiting or preventing clogging of particles at a wet-dry interface between the particles and a liquid. Thus, e.g., the flush system 100 may be configured to assist with controlling the wet-dry interface between superabsorbent material and foam in the component feed system 40 (FIGS. 1 through 3), and the flush system 100 is described in greater detail below in the context of the component feed system 40. However, it will be understood that the flush system 100 may be used with other particles, such as fibers, pigments, thermally expandable microspheres, foam particles, etc. to limit or prevent system interruptions due to particles sticking to components.

As shown in FIG. 4, the flush system 100 may be disposed between a particle meter 200 and an eductor 210. Moreover, the flush system 100 may be disposed downstream of the particle meter 200 and upstream of the eductor 210 relative to a flow of superabsorbent material SAM from the particle meter 200 to the eductor 210. In example embodiments, the flush system 100 may be disposed vertically between the particle meter 200 and the eductor 210, e.g., such that the particle meter 200 is disposed above the flush system 100 and the eductor 210 is disposed below the flush system 100. In example embodiments, the flush system 100 may be spaced from and/or positioned above the eductor 210 by no less than thirty centimeters (30 cm) and no greater than three hundred centimeters (300 cm).

The particle meter 200 is configured for supplying the flow of superabsorbent material SAM to the flush system 100. The particle meter 200 may include a hopper 202. The hopper 202 may be utilized for refiling a supply of the superabsorbent material SAM. For instance, a user may fill the hopper 202 to provide a reservoir of superabsorbent material SAM for a headbox (not shown) located downstream of the eductor 210. In example embodiments, the particle meter 200 may include a bulk solids pump, such as screws/augers, conveyor systems, belts, vibratory trays, rotating discs, or other known systems for handling and discharging the superabsorbent material SAM in a controlled, metered manner.

The eductor 210 is configured for directing the flow of superabsorbent material SAM into a flow of foam FF. Moreover, the eductor 210 may be fluidly connected to a pump or other fluid displacement mechanism that urges the flow of foam FF through the eductor 210. The eductor 210 may be shaped and arranged such that the flow of foam FF acts as a motive fluid to entrain the flow of superabsorbent material SAM from the particle meter 200 into the flow of foam FF. For instance, the eductor 210 may include a converging cross-sectional area, and a velocity of the flow of foam FF at the converging cross-sectional area may increase, which results in a pressure of the flow of foam FF at the converging cross-sectional area decreasing in order to entrain the flow of superabsorbent material SAM into the flow of foam FF. Thus, the eductor 210 may be configured to combine the flow of superabsorbent material SAM from the particle meter 200 with the flow of foam FF and direct the combined flow of superabsorbent material and foam CF to the downstream headbox to form personal care products.

As noted above, the flush system 100 may be disposed between the particle meter 200 and the eductor 210 on the flow of superabsorbent material SAM from the particle meter 200 to the eductor 210. As described in greater detail below, the flush system 100 may assist with controlling a wet-dry interface between the flow of superabsorbent material SAM and the flow of foam FF. Moreover, as the eductor 210 entrains the flow of superabsorbent material SAM from the particle meter 200 into the flow of foam FF, the foam FF from the eductor 210 can splash towards the particle meter 200. The liquid in the foam FF can cause the superabsorbent material SAM to stick on the eductor 210 and other system components. The clogged superabsorbent material SAM can back up into other portions of the system and/or cause other problems. The flush system 100 can advantageously assist with limiting or preventing such clogging.

As shown in FIG. 5, the flush system 100 may include a particle inlet conduit 110. The particle inlet conduit 110 may be configured for receiving the flow of superabsorbent material SAM from the particle meter 200. For instance, the particle inlet conduit 110 may be disposed below the particle meter 200, and the particle inlet conduit 110 may be gravity-fed the superabsorbent material SAM from the particle meter 200. For instance, the superabsorbent material SAM may flow downwardly from the particle meter 200 into the particle inlet conduit 110. In example embodiments, the particle inlet conduit 110 may include a cylindrical wall 112 extending longitudinally between a top end portion 114 and a bottom end portion 116. The flow of superabsorbent material SAM from the particle meter 200 may enter the particle inlet conduit 110 at the top end portion 114 of the cylindrical wall 112, pass through the particle inlet conduit 110, and then exit the particle inlet conduit 110 at the bottom end portion 116 of the cylindrical wall 112.

The flush system 100 may also include an air inlet plenum 120. The air inlet plenum 120 may be disposed around the particle inlet conduit 110 and may be configured for directing a plurality of air flows AF into the particle inlet conduit 110. For instance, the air inlet plenum 120 may extend around the cylindrical wall 112 of the particle inlet conduit 110 between the top and bottom end portions 114, 116 of the cylindrical wall 112. Thus, e.g., the air inlet plenum 120 may define an annulus around the particle inlet conduit 110.

In example embodiments, the air inlet plenum 120 may include a plurality of ports 122. The ports 122 may be distributed around the particle inlet conduit 110. For instance, the ports 122 may be uniformly distributed around a circumference of the cylindrical wall 112, and the ports 122 may extend radially through the cylindrical wall 112. Thus, e.g., the ports 122 may be distributed in a ring around the particle inlet conduit 110 in example embodiments. The air flows AF may thus pass through the cylindrical wall 112 from the air inlet plenum 120 into an interior of the particle inlet conduit 110, e.g., with the flow of superabsorbent material SAM from the particle meter 200.

As noted above, the eductor 210 can entrain the flow of superabsorbent material SAM into the flow of foam FF by reducing the pressure of the flow of foam FF. Because the eductor 210 can generate vacuum during operation, the eductor 210 may be disposed within a sealed system 212, such as a casing, to control the amount of air that bleeds into the combined flow of superabsorbent material and foam CF to the headbox. By bleeding air into the particle inlet conduit 110, the flush system 100 may be configured for controlling the vacuum level within the sealed system 212. The air flows AF may also advantageously direct the flow of superabsorbent material SAM towards a center of the particle inlet conduit 110 and/or form a barrier between the wall(s) of the particle inlet conduit 110 and the superabsorbent material SAM, which can assist with limiting or preventing sticking of the superabsorbent material SAM to the particle inlet conduit 110. The air flows AF may also advantageously assist with fluidizing the flow of superabsorbent material SAM.

In example embodiments, the air inlet plenum 120 may include no less than ten (10) ports 122. For instance, the air inlet plenum 120 may include no less than twelve (12) and no greater than one hundred (100) ports 122 in some example embodiments. Such numbers of ports 122 may advantageously assist with bleeding a constant pressure air header into the air inlet plenum 120. It will be understood that other numbers of ports 122 may be used in other example embodiments. In some example embodiments, the ports 122 may be combined into a single opening or slit.

The ports 122 may be oriented for forming a desired pattern of the air flows AF. For instance, the ports 122 may be oriented such that the air flows AF have a swirling or helical pattern on the cylindrical wall 112 of the particle inlet conduit 110, such as that shown in FIG. 6. Thus, e.g., the ports 122 may be oriented at an angle relative to vertical, e.g., between about five degrees (5°) and forty- five degrees (45°) relative to vertical. The ports 122 may be oriented at an angle relative to radial, e.g., between about five degrees (5°) and forty-five degrees (45°) relative to radial. Such angling can assist with forming the air flows AF with the swirling or helical pattern on the cylindrical wall 112 of the particle inlet conduit 110. In other example embodiments, the ports 122 may be oriented such that the air flows AF have a straight pattern on the cylindrical wall 112 of the particle inlet conduit 110 relative to vertical. Thus, e.g., the ports 122 may be oriented at an angle relative to vertical, e.g., between about five degrees (5°) and sixty degrees (60°) relative to vertical. The ports 122 may be oriented at an angle relative to radial, e.g., between about negative five degrees (-5°) and five degrees (5°) relative to radial. Such angling can assist with forming the air flows AF with the straight pattern on the cylindrical wall 112 of the particle inlet conduit 110.

The flush system 100 may also include an outlet conduit 130. The outlet conduit 130 may be disposed downstream of the particle inlet conduit 110 and may be configured for receiving a combined flow of the air flows AF and the flow of superabsorbent material SAM from the particle inlet conduit 110. For instance, the outlet conduit 130 may include may be disposed below the particle inlet conduit 110, and the outlet conduit 130 may be gravity-fed the superabsorbent material SAM from the particle inlet conduit 110. For instance, the superabsorbent material SAM may flow downwardly from the particle inlet conduit 110 into the outlet conduit 130. The air flows AF may also assist with flowing the superabsorbent material SAM from the particle inlet conduit 110 into the outlet conduit 130. In example embodiments, the outlet conduit 130 may include a cylindrical wall 132 extending longitudinally between a top end portion 134 and a bottom end portion 136. The flow of superabsorbent material SAM from the particle inlet conduit 110 may enter the outlet conduit 130 at the top end portion 134 of the cylindrical wall 132 (or between the top and bottom end portions 134, 136 of the cylindrical wall 132), pass through the outlet conduit 130, and then exit the outlet conduit 130 at the bottom end portion 136 of the cylindrical wall 132.

As shown in FIG. 8, the flush system 100 may not include the air inlet plenum 120 and ports 122 in some example embodiments. Thus, in some example embodiments, the flow of superabsorbent material SAM from the particle inlet conduit 110 may pass through the outlet conduit 130 without added air from a pressurized air plenum of the flush system 100.

Turning back to FIG. 5, the flush system 100 may also include a fluid inlet plenum 140. The fluid inlet plenum 140 may be disposed around the outlet conduit 130 and may be configured for directing a plurality of fluid flows FLF into the outlet conduit 130. For instance, the fluid inlet plenum 140 may extend around the cylindrical wall 132 of the outlet conduit 130 between the top and bottom end portions 134, 136 of the cylindrical wall 132. Thus, e.g., the fluid inlet plenum 140 may define an annulus around the outlet conduit 130. As an example, the fluid inlet plenum 140 may be disposed around the outlet conduit 130 between the top and bottom end portions 134, 136 of the cylindrical wall 132.

In example embodiments, the fluid inlet plenum 140 may include a plurality of ports 142. The ports 142 may be distributed around the outlet conduit 130. For instance, the ports 142 may be uniformly distributed around a circumference of the cylindrical wall 132, and the ports 142 may extend radially through the cylindrical wall 132. Thus, e.g., the ports 142 may be distributed in a ring around the outlet conduit 130 in example embodiments. The fluid flows FLF may thus pass through the cylindrical wall 132 from the fluid inlet plenum 140 into an interior of the outlet conduit 130, e.g., with the flow of superabsorbent material SAM from the particle inlet conduit 110.

As noted above, liquid in the foam FF can cause the superabsorbent material SAM to stick on the eductor 210 and other system components. The clogged superabsorbent material SAM can back up into other portions of the system and/or cause other problems. The flush system 100 can advantageously assist with limiting or preventing such clogging. Moreover, liquid in the fluid flows FLF, such as water, surfactant laden water, or foam, flowing into the outlet conduit 130 from the fluid inlet plenum 140 may flow over and/or coat the outlet conduit 130, e.g., to limit or prevent the superabsorbent material SAM from clogging. The fluid flows FLF may thus continually flush and clean any superabsorbent material SAM that sticks to the outlet conduit 130 in order to limit or prevent the system interruptions. In example embodiments, the fluid flows FLF may form a continuous, e.g., cylindrical, film from the flush system 100 to the eductor 210 to limit or prevent the superabsorbent material SAM from clogging the flow path between the flush system 100 and the eductor 210.

In example embodiments, the fluid inlet plenum 140 may include no less than ten (10) ports 142. For instance, the fluid inlet plenum 140 may include no less than twelve (12) and no greater than one hundred (100) ports 142 in some example embodiments. Such numbers of ports 142 may advantageously assist with bleeding a constant pressure fluid header into the fluid inlet plenum 140. It will be understood that other numbers of ports 142 may be used in other example embodiments. In some example embodiments, the ports 142 may be combined into a single opening or slit.

The ports 142 may be oriented for forming a desired pattern of the fluid flows FLF. For instance, the ports 142 may be oriented such that the fluid flows FLF have a swirling or helical pattern on the cylindrical wall 132 of the outlet conduit 130, such as that shown in FIG. 6. Thus, e.g., the ports 142 may be oriented at an angle relative to vertical, e.g., between about five degrees (5°) and forty- five degrees (45°) relative to vertical. The ports 142 may be oriented at an angle relative to radial, e.g., between about five degrees (5°) and forty-five degrees (45°) relative to radial. Such angling can assist with forming the fluid flows FLF with the swirling or helical pattern on the cylindrical wall 132 of the outlet conduit 130. In other example embodiments, the ports 142 may be oriented such that the fluid flows FLF have a straight pattern on the cylindrical wall 132 of the outlet conduit 130 relative to vertical. Thus, e.g., the ports 142 may be oriented at an angle relative to vertical, e.g., between about five degrees (5°) and sixty degrees (60°) relative to vertical. The ports 142 may be oriented at an angle relative to radial, e.g., between about negative five degrees (-5°) and five degrees (5°) relative to radial. Such angling can assist with forming the fluid flows FLF with the straight pattern on the cylindrical wall 132 of the outlet conduit 130. The ports 142 may also be oriented for directing the fluid flows FLF generally parallel to the surface of the cylindrical wall 132 below the ports 142, which can facilitate maintaining a liquid coating on the cylindrical wall 132 to flush and clean any superabsorbent material SAM from the particle inlet conduit 110 that sticks to the outlet conduit 130.

As shown in FIG. 5, at least a portion of the particle inlet conduit 110 may be received within the outlet conduit 130, e.g., between the top and bottom portions 134, 136 of the cylindrical wall 132. For example, a distal end portion 118 of the particle inlet conduit 110, which may correspond to the bottom end portion 116 of the cylindrical wall 112 may be disposed within the outlet conduit 130. Thus, e.g., the particle inlet conduit 110 may extend within the outlet conduit 130 past the ports 142 of the fluid inlet plenum 140 in example embodiments. The particle inlet conduit 110 also may be arranged coaxial with the outlet conduit 130, e.g., along an axis X of the flush system 100.

In example embodiments, the flush system 100 may include a drip ring 150. The drip ring 150 may be disposed at the distal end portion 118 of the particle inlet conduit 110. Moreover, the drip ring 150 may extend downwardly from the particle inlet conduit 110, e.g., into the interior of the outlet conduit 130. In example embodiment, the drip ring 150 may extend downwardly from the particle inlet conduit 110 by no less than five millimeters (5 mm) and no less than fifty millimeters (50 mm). The drip ring 150 may also be disposed radially outward of an outlet of the particle inlet conduit 110 at the distal end portion 118 of the particle inlet conduit 110. The drip ring 150 may direct liquids flowing down the particle inlet conduit 110, e.g., towards the bottom end portion 116 of the cylindrical wall 112, away from the flow of superabsorbent material SAM from the particle inlet conduit 110 into the outlet conduit 130. Thus, the drip ring 150 may assist with keeping the superabsorbent material SAM dry within the particle inlet conduit 110. Further, the drip ring 150 limit or prevent the superabsorbent material SAM from clogging at the distal end portion 118 of the particle inlet conduit 110.

In example embodiments, the outlet of the particle inlet conduit 110 at the distal end portion 118 of the particle inlet conduit 110 may be spaced from the inner surface(s) of outlet conduit 130 that faces towards the particle inlet conduit 110 within the interior of the outlet conduit 130. For instance, a radial spacing of the outlet of the particle inlet conduit 110 from the inner surface(s) of outlet conduit 130 may be no less than ten millimeters (10 mm), such as no less than twenty millimeters (20 mm), such as no less than thirty millimeters (30 mm), and no greater than two hundred millimeters (200 mm), such as no greater than one hundred and fifty millimeters (150 mm), such as no greater than one hundred millimeters (100 mm), in some example embodiments.

In the example embodiment shown in FIG. 5, the interior of the particle inlet conduit 110 may converge from the top end portion 114 of the cylindrical wall 112 and the bottom end portion 116 of the cylindrical wall 112, e.g., along the axis X. Thus, e.g., an inner diameter of the cylindrical wall 112 may decrease (e.g., monotonically) from the top end portion 114 of the cylindrical wall 112 to the bottom end portion 116 of the cylindrical wall 112, e.g., along the axis X. The interior of the outlet conduit 130 may also converge from the top end portion 134 of the cylindrical wall 132 and the bottom end portion 136 of the cylindrical wall 132, e.g., along the axis X. Thus, e.g., an inner diameter of the cylindrical wall 132 may decrease from the top end portion 134 of the cylindrical wall 132 and the bottom end portion 136 of the cylindrical wall 132, e.g., along the axis X. Moreover, e.g., the inner diameter of the cylindrical wall 132 may decrease (e.g., monotonically) from the ports 142 of the fluid inlet plenum 140 to the bottom end portion 136 of the cylindrical wall 132, e.g., along the axis X. Above, the ports 142 of the fluid inlet plenum 140, the inner diameter of the cylindrical wall 132 may also decrease (e.g., monotonically) from the ports 142 of the fluid inlet plenum 140 to the top end portion 134 of the cylindrical wall 132. The ports 142 of the fluid inlet plenum 140 may thus be disposed at a radially outward-most portion of the interior of the outlet conduit 130 in example embodiments. With reference to FIG. 3, the flush system 100 may also include features for regulating material flows into the flush system 100. For instance, the flush system 100 may include an air valve 160 and a fluid valve 170. The air valve 160 may be coupled to the air inlet plenum 120. The air valve 160 may be configured for regulating an air supply 162 to the air inlet plenum 120. Thus, e.g., the air valve 160 may control the air flows AF into the particle inlet conduit 110 in order to create a substantially constant pressure air header around the flow of superabsorbent material SAM in the particle inlet conduit 110. In addition, the air valve 160 may control the air flows AF into the particle inlet conduit 110 to control the amount of air that bleeds into the combined flow of superabsorbent material and foam CF to the headbox In example embodiments, the air valve 160 may control the air flows AF based upon pressure measurements from one or more sensors 180, e.g., for the flow of foam FF.

The fluid valve 170 may be coupled to the fluid inlet plenum 140. The fluid valve 170 may be configured for regulating a fluid supply 172 to the fluid inlet plenum 140. Thus, e.g., the fluid valve 170 may control the fluid flows FLF into the particle inlet conduit 110 in order to create a substantially constant pressure fluid header around the flow of superabsorbent material SAM in the outlet conduit 130. In addition, the fluid valve 170 may control the fluid flows FLF into the outlet conduit 130 to provide laminar fluid flows FLF into the outlet conduit 130.

As may be seen from the above, the flush system 100 can facilitate introduction of particles into a liquid stream. The flush system 100 may also include features for limiting or preventing particle collection or clumping due contact with the liquid.

As noted above, in example embodiments, the flush system 100 may not include the air inlet plenum 120 or may not utilize the air flows AF during metering of the superabsorbent material SAM in the outlet conduit 130. Thus, e.g., air may bleed into the sealed system 212 at other locations.

Formation Method:

FIG. 7 shows a method 700 for introducing a component into a fluid supply and forming a substrate, such as an absorbent body, according to an example embodiment of the present subject matter. Method 700 is described in greater detail below in the context of the apparatus 10 (FIGS. 1 through 3) and the flush system 100 (FIGS. 4 and 5). However, it will be understood that method 700 may be used in or with other systems in other example embodiments.

At 710, the method 700 may include metering a flow of particles in a sealed system. For example, the particle meter 200 may supply the flow of superabsorbent material SAM to the flush system 100 at 710. An air pressure within the sealed system may be less than ambient atmospheric pressure around the sealed system at 710. For example, an interior of the interior of the flush system 100 may be subjected to vacuum due to the eductor 210 generating vacuum during operation. The particles may include superabsorbent material and/or other particles, such as dry fibers , .pulped cellulose fibers, etc.

At 720, a flow of air may be bled into the flow of particles in order to form a combined stream of air and particles. For example, the air inlet plenum 120 may direct the air flows AF into the particle inlet conduit 110 with the flow of superabsorbent material SAM at 720. In example embodiments, the air valve 160 may open at 720 to flow air from the air supply 162 to the air inlet plenum 120 such that the air inlet plenum 120 directs the air flows AF into the particle inlet conduit 110 with the flow of superabsorbent material SAM. For instance, the air valve 160 may control the air flows AF based upon pressure measurements from one or more sensors 180, e.g., for the flow of foam FF. As noted above, bleeding the air flows AF into the particle inlet conduit 110 may control the vacuum level within the sealed system. In addition, the air flows AF may also advantageously direct the flow of superabsorbent material SAM towards a center of the particle inlet conduit 110 and/or form a barrier between the wall(s) of the particle inlet conduit 110 and the superabsorbent material SAM, which can assist with limiting or preventing sticking of the superabsorbent material SAM to the particle inlet conduit 110.

It will be understood that bleeding air into the flow of particles is optional and that the method 700 may omit bleeding air into the flow of particles at 720 in some example embodiments.

At 730, a plurality of fluid flows may flow into a conduit. The fluid flows may coat a surface of the conduit with liquid from the plurality of fluid flows at 730. As an example, the fluid valve 170 may open at 730 to flow air from the fluid supply 172 to the fluid inlet plenum 140 such that the fluid inlet plenum 140 directs the fluid flows FLF into the outlet conduit 130. For instance, the fluid valve 170 may control the fluid flows FLF based upon pressure measurements from one or more sensors 180, e.g., for the flow of foam FF. Liquid, such as water, surfactant laden water (e.g., to match or complement the formulation of the foaming fluid), or foam, from the fluid flows FLF may flow over and/or coat the outlet conduit 130 at 730. For instance, the fluid flows FLF may form a swirling pattern on a surface of the outlet conduit 130.

At 740, the combined stream of air and particles may be flowed through the conduit towards an eductor. The fluid flows may coat the surface of the conduit with liquid from the plurality of fluid flows at 740. The method 700 may also include flushing the particles towards the eductor with the fluid flows. For example, the fluid flows FLF may continually flush and clean any superabsorbent material SAM that sticks to the outlet conduit 130 in order to limit or prevent the system interruptions at 740. In example embodiments, each of the fluid flows FLF may exit a respective one of ports 142 distributed around the outlet conduit 130. The fluid flows FLF may coat a surface of the outlet conduit 130 with liquid in a plane that is perpendicular to the central axis X below the distal end portion 118 of the particle inlet conduit 110 at 740. For example, the fluid flows FLF may coat the surface of the outlet conduit 130 and form a continuous, e.g., cylindrical, barrier of liquid between the combined flow of the air flows AF and the flow of superabsorbent material SAM and the surface of the outlet conduit 130. The ports 142 may also be oriented such that the fluid flows FLF are substantially parallel to the surface of the outlet conduit 130 at 740. Moreover, the fluid flows FLF may be laminar fluid flows.

The method 700 may also include entraining the particles into a flow of foam at the eductor. For example, the eductor 210 may entrain the flow of superabsorbent material SAM from the particle meter 200 into the flow of foam FF. The method 700 may further include flowing the flow of foam with the entrained particles to a headbox.

FIG. 7 depicts steps performed in a particular order for purposes of illustration and discussion. Those of ordinary skill in the art, using the disclosures provided herein, will understand that the steps of any of the methods discussed herein may be adapted, rearranged, expanded, omitted, or modified in various ways without deviating from the scope of the present disclosure.

Foaming Fluid:

The foam forming processes as described herein may include a foaming fluid. In some example embodiments, the foaming fluid may include between about eighty-five percent (85%) to about ninety-nine and ninety-nine hundredths percent (99.99%) of the foam (by weight). In some example embodiments, the foaming fluid used to make the foam may include at least about eighty-five percent (85%) of the foam (by weight). In certain example embodiments, the foaming fluid may include between about ninety percent (90%) and about ninety-nine and nine-tenths percent (99.9%) of the foam (by weight). In certain other example embodiments, the foaming fluid may include between about ninety-three percent (93%) and ninety-nine and five-tenths percent (99.5%) of the foam or even between about ninety-five percent (95%) and about ninety-nine percent (99.0%) of the foam (by weight). In preferred example embodiments, the foaming fluid may be water, however, it is contemplated that other processes may utilize other foaming fluids.

Foaming Surfactant:

The foam forming processes as described herein may utilize one of more surfactants. The fibers and surfactant, together with the foaming liquid and any additional components, may form a stable dispersion capable of substantially retaining a high degree of porosity for longer than the drying process. In this regard, the surfactant may be selected so as to provide a foam having a foam half-life of at least two (2) minutes, more desirably at least five (5) minutes, and most desirably at least ten (10) minutes. A foam half-life may be a function of surfactant types, surfactant concentrations, foam compositions/solid level and mixing power/air content in a foam. The foaming surfactant used in the foam may be selected from one or more known in the art that are capable of providing the desired degree of foam stability. In this regard, the foaming surfactant may be selected from anionic, cationic, nonionic, and amphoteric surfactants provided the foaming surfactants, alone or in combination with other components, provide the necessary foam stability, or foam half-life. As will be appreciated, more than one surfactant may be used, including different types of surfactants, as long as the surfactants are compatible, and more than one surfactant of the same type. For example, a combination of a cationic surfactant and a nonionic surfactant or a combination of an anionic surfactant and a nonionic surfactant may be used in some example embodiments due to compatibilities. However, in some example embodiments, a combination of a cationic surfactant and an anionic surfactant may not be satisfactory to combine due to incompatibilities between the surfactants.

Anionic surfactants believed suitable for use with the present disclosure include, without limitation, anionic sulfate surfactants, alkyl ether sulfonates, alkylaryl sulfonates, or mixtures or combinations thereof. Examples of alkylaryl sulfonates include, without limitation, alkyl benzene sulfonic acids and their salts, dialkylbenzene disulfonic acids and their salts, dialkylbenzene sulfonic acids and their salts, alkylphenol sulfonic acids/condensed alkylphenol sulfonic acids and their salts, or mixture or combinations thereof. Examples of additional anionic surfactants believed suitable for use in the present disclosure include alkali metal sulforicinates, sulfonated glyceryl esters of fatty acids such as sulfonated monoglycerides of coconut oil acids, salts of sulfonated monovalent alcohol esters such as sodium oleylisethianate, metal soaps of fatty acids, amides of amino sulfonic acids such as the sodium salt of oleyl methyl tauride, sulfonated products of fatty acids nitriles such as palmitonitrile sulfonate, alkali metal alkyl sulfates such as sodium lauryl sulfate, ammonium lauryl sulfate or triethanolamine lauryl sulfate, ether sulfates having alkyl groups of eight (8) or more carbon atoms, such as sodium lauryl ether sulfate, ammonium lauryl ether sulfate, sodium alkyl aryl ether sulfates, and ammonium alkyl aryl ether sulfates, sulphuric esters of polyoxyethylene alkyl ether, sodium salts, potassium salts, and amine salts of alkylnapthylsulfonic acid. Certain phosphate surfactants including phosphate esters, such as sodium lauryl phosphate esters or those available from the Dow Chemical Company under the tradename TRITON are also believed suitable for use herewith. A particularly desired anionic surfactant is sodium dodecyl sulfate (SDS).

Cationic surfactants are also believed suitable for use with the present disclosure for manufacturing some example embodiments of substrates. In some example embodiments, such as those including superabsorbent material, cationic surfactants may be less preferable to use due to potential interaction between the cationic surfactant(s) and the superabsorbent material, which may be anionic. Foaming cationic surfactants include, without limitation, monocarbyl ammonium salts, dicarbyl ammonium salts, tricarbyl ammonium salts, monocarbyl phosphonium salts, dicarbyl phosphonium salts, tricarbyl phosphonium salts, carbylcarboxy salts, quaternary ammonium salts, imidazolines, ethoxylated amines, quaternary phospholipids and so forth. Examples of additional cationic surfactants include various fatty acid amines and amides and their derivatives, and the salts of the fatty acid amines and amides. Examples of aliphatic fatty acid amines include dodecylamine acetate, octadecylamine acetate, and acetates of the amines of tallow fatty acids, homologues of aromatic amines having fatty acids such as dodecylanalin, fatty amides derived from aliphatic diamines such as undecylimidazoline, fatty amides derived from aliphatic diamines such as undecylimidazoline, fatty amides derived from disubstituted amines such as oleylaminodiethylamine, derivatives of ethylene diamine, quaternary ammonium compounds and their salts which are exemplified by tallow trimethyl ammonium chloride, dioctadecyldimethyl ammonium chloride, didodecyldimethyl ammonium chloride, dihexadecyl ammonium chloride, alkyltrimethylammonium hydroxides, dioctadecyldimethylammonium hydroxide, tallow trimethylammonium hydroxide, trimethylammonium hydroxide, methylpolyoxyethylene cocoammonium chloride, and dipalmityl hydroxyethylammonium methosulfate, amide derivatives of amino alcohols such as beta-hydroxylethy Istearylamide, and amine salts of long chain fatty acids. Further examples of cationic surfactants believed suitable for use with the present disclosure include benzalkonium chloride, benzethonium chloride, cetrimonium bromide, distearyldimethylammonium chloride, tetramethylammonium hydroxide, and so forth.

Nonionic surfactants believed suitable for use in the present disclosure include, without limitation, condensates of ethylene oxide with a long chain fatty alcohol or fatty acid, condensates of ethylene oxide with an amine or an amide, condensation products of ethylene and propylene oxides, fatty acid alkylol amide and fatty amine oxides. Various additional examples of non-ionic surfactants include stearyl alcohol, sorbitan monostearate, octyl glucoside, octaethylene glycol monododecyl ether, lauryl glucoside, cetyl alcohol, cocamide MEA, monolaurin, polyoxyalkylene alkyl ethers such as polyethylene glycol long chain (12-14C) alkyl ether, polyoxyalkylene sorbitan ethers, polyoxyalkylene alkoxylate esters, polyoxyalkylene alkylphenol ethers, ethylene glycol propylene glycol copolymers, polyvinyl alcohol, alkylpolysaccharides, polyethylene glycol sorbitan monooleate, octylphenol ethylene oxide, and so forth.

The foaming surfactant may be used in varying amounts as necessary to achieve the desired foam stability and air-content in the foam. In certain example embodiments, the foaming surfactant may include between about five-thousandths percent (0.005%) and about five percent (5%) of the foam (by weight). In certain example embodiments, the foaming surfactant may include between about five-hundredths percent (0.05%) and about three percent (3%) of the foam or even between about five- hundredths percent (0.05%) and about two percent (2%) of the foam (by weight).

Fibers:

As noted above, the apparatus 10 and methods described herein may include providing a fibers from a supply of fibers 18. In some example embodiments, the fibers may be suspended in a fluid supply 16, 28 that may be a foam. The foam suspension of fibers may provide one or more supply of fibers. In some example embodiments, the fibers utilized herein may include natural fibers and/or synthetic fibers. In some example embodiments, a fiber supply 18 may include only natural fibers or only synthetic fibers. In other example embodiments, a fiber supply 18 may include a mixture of natural fibers and synthetic fibers. Some fibers being utilized herein may be absorbent, whereas other fibers utilized herein may be non-absorbent. Non-absorbent fibers may provide features for the substrates that are formed from the methods and apparatuses described herein, such as improved intake or distribution of fluids.

A wide variety of cellulosic fibers are believed suitable for use herein. In some example embodiments, the fibers utilized may be conventional papermaking fibers such as wood pulp fibers formed by a variety of pulping processes, such as kraft pulp, sulfite pulp, bleached chemithermomechanical pulp (BCTMP), chemithermomechanical pulp (CTMP), pressure/pressure thermomechanical pulp (PTMP), thermomechanical pulp (TMP), thermomechanical chemical pulp (TMCP), and so forth. By way of example only, fibers and methods of making wood pulp fibers are disclosed in US4793898 to Laamanen et al. US4594130 to Chang et al.; US3585104 to Kleinhart; US5595628 to Gordon et al.; US5522967 to Shet; and so forth, which are incorporated by reference herein in their entireties. Further, the fibers may be any high-average fiber length wood pulp, low- average fiber length wood pulp, or mixtures of the same. Examples of suitable high-average length pulp fibers include softwood fibers, such as, but not limited to, northern softwood, southern softwood, redwood, red cedar, hemlock, pine (e.g., southern pines), spruce (e.g., black spruce), and the like. Examples of suitable low-average length pulp fibers include hardwood fibers, such as, but not limited to, eucalyptus, maple, birch, aspen, and the like.

Moreover, if desired, secondary fibers obtained from recycled materials may be used, such as fiber pulp from sources, such as, for example, newsprint, reclaimed paperboard, and office waste. In a particularly preferred example embodiment, refined fibers are utilized in the tissue web such that the total amount of virgin and/or high average fiber length wood fibers, such as softwood fibers, may be reduced. Regardless of the origin of the wood pulp fiber, the wood pulp fibers preferably have an average fiber length greater than about two-tenths millimeter (0.2 mm) and less than about three millimeters (3 mm), such as from about thirty-five hundredths millimeter (0.35 mm) and about two and half millimeters (2.5 mm), or between about half millimeter (0.5 mm) to about two millimeters (2 mm) or even between about seven-tenths millimeter (0.7 mm) and about one and a half millimeters (1 .5 mm).

In addition, other cellulosic fibers that may be used in the present disclosure includes nonwoody fibers. As used herein, the term “non-wood fiber” generally refers to cellulosic fibers derived from non-woody monocotyledonous or dicotyledonous plant stems. Non-limiting examples of dicotyledonous plants that may be used to yield non-wood fiber include kenaf, jute, flax, ramie and hemp. Non-limiting examples of monocotyledonous plants that may be used to yield non-wood fiber include cereal straws (wheat, rye, barley, oat, etc.), stalks (corn, cotton, sorghum, Hesperaloe funifera, etc.), canes (bamboo, sisal, bagasse, etc.) and grasses (miscanthus. esparto, lemon, sabai, switchgrass, etc). In still other certain instances, non-wood fiber may be derived from aquatic plants such as water hyacinth, microalgae such as Spirulina, and macroalgae seaweeds, such as red or brown algae.

Still further, other cellulosic fibers for making substrates herein may include synthetic cellulose fiber types formed by spinning, including rayon in all varieties, and other fibers derived from viscose or chemically-modified cellulose such as, for example, those available under the trade names LYOCELL and TENCEL.

In some example embodiments, the non-woody and synthetic cellulosic fibers may have fiber length greater than about two-tenths millimeter (0.2 mm) including, for example, having an average fiber size between about a half millimeter (0.5 mm) and about fifty millimeters (50 mm) or between about three-quarters millimeter (0.75 mm) and about thirty millimeters (30 mm) or even between about one millimeter (1 mm) and about twenty-five millimeters (25 mm). Generally speaking, when fibers of relatively larger average length are being used, it may often be advantageous to modify the amount and type of foaming surfactant. For example, in some example embodiments, if fibers of relatively larger average length are being used, it may be beneficial to utilize relatively higher amounts of foaming surfactant in order to help achieve a foam with the required foam half-life.

Additional fibers that may be utilized in the present disclosure include fibers that are resistant to the forming fluid, namely those that are non-absorbent and whose bending stiffness is substantially unimpacted by the presence of forming fluid. As noted above, typically the forming fluid will include water. By way of non-limiting example, water-resistant fibers include fibers such as polymeric fibers including polyolefin, polyester (PET), polyamide, polylactic acid, or other fiber forming polymers. Polyolefin fibers, such as polyethylene (PE) and polypropylene (PP), are particularly well suited for use in the present disclosure. In some example embodiments, non-absorbent fibers may be recycled fibers, compostable fibers, and/or marine degradable fibers. In addition, highly cross-linked cellulosic fibers having no-significant absorbent properties may also be used herein. In this regard, due to very low levels of absorbency to water, water resistant fibers do not experience a significant change in bending stiffness upon contacting an aqueous fluid and therefore are capable of maintain an open composite structure upon wetting. The fiber diameter of a fiber may contribute to enhanced bending stiffness. For example, a PET fiber has a higher bending stiffness than a polyolefin fiber whether in dry or wet states. The higher the fiber denier, the higher the bending stiffness a fiber exhibits. Water resistant fibers desirably have a water retention value (WRV) less than about one (1) and still more desirably between about zero (0) and about a half (0.5). In certain example aspects, it is desirable that the fibers, or at least a portion thereof, include non-absorbent fibers.

The synthetic and/or water resistant fibers may have fiber length greater than about two-tenths millimeter (0.2 mm) including, for example, having an average fiber size between about a half millimeter (0.5 mm) and about fifty millimeters (50 mm) or between about three-quarters millimeter (0.75) and about thirty millimeters (30 mm) or even between about one millimeter (1 mm) and about twenty-five millimeters (25 mm).

In some example embodiments, the synthetic and/or water-resistant fibers may have a crimped structure to enhance bulk generation capability of the foam formed fibrous substrate. For example, a PET crimped staple fiber may be able to generate a higher caliper (or result in a low sheet density) in comparison to a PET straight staple fiber with the same fiber diameter and fiber length.

In some example embodiments, the total content of fibers, may include between about one- hundredth percent (0.01 %) to about ten percent (10%) of the foam (by weight), and in some example embodiments between about one-tenth percent (0.1%) to about five percent (5%) of the foam (by weight).

Binder:

In some example embodiments, a fluid supply 16, 28 may include binder materials. Binder materials that may be used in the present disclosure may include, but are not limited to, thermoplastic binder fibers, such as PET/PE bicomponent binder fiber, and water-compatible adhesives such as, for example, latexes. In some example embodiments, binder materials as used herein may be in powder form, for example, such as thermoplastic PE powder. Importantly, the binder may include one that is water insoluble on the dried substrate. In certain example embodiments, latexes used in the present disclosure may be cationic or anionic to facilitate application to and adherence to cellulosic fibers that may be used herein. For instance, latexes believed suitable for use include, but are not limited to, anionic styrene-butadiene copolymers, polyvinyl acetate homopolymers, vinyl-acetate ethylene copolymers, vinyl-acetate acrylic copolymers, ethylene-vinyl chloride copolymers, ethylene-vinyl chloride-vinyl acetate terpolymers, acrylic polyvinyl chloride polymers, acrylic polymers, nitrile polymers, as well as other suitable anionic latex polymers known in the art. Examples of such latexes are described in US4785030 to Hager, US6462159 to Hamada, US6752905 to Chuang et al. and so forth. Examples of suitable thermoplastic binder fibers include, but are not limited to, monocomponent and multi-component fibers having at least one relatively low melting thermoplastic polymer such as polyethylene. In certain example embodiments, polyethylene/polypropylene sheath/core staple fibers may be used. Binder fibers may have lengths in line with those described herein above in relation to the synthetic cellulosic fibers.

Binders in liquid form, such as latex emulsions, may include between about zero percent (0%) and about ten percent (10%) of the foam (by weight). In certain example embodiments the non-fibrous binder may include between about one-tenth percent (0.1%) and ten percent (10%) of the foam (by weight) or even between about two-tenths percent (0.2%) and about five percent (5%) or even between about a half percent (0.5%) and about two percent (2%) of the foam (by weight). Binder fibers, when used, may be added proportionally to the other components to achieve the desired fiber ratios and structure while maintaining the total solids content of the foam below the amounts stated above. As an example, in some example embodiments, binder fibers may include between about zero percent (0%) and about fifty percent (50%) of the total fiber weight, and more preferably, between about five percent (5%) to about forty percent (40%) of the total fiber weight in some example embodiments.

Foam Stabilizers:

In some example embodiments, if a fluid supply 16, 28 is configured as a foam, the foam may optionally also include one or more foam stabilizers known in the art and that are compatible with the components of the foam and further do not interfere with the hydrogen bonding as between the cellulosic fibers. Foam stabilizing agents believed suitable for use in the present disclosure, without limitation, one or more zwitterionic compounds, amine oxides, alkylated polyalkylene oxides, or mixture or combinations thereof. Specific examples of foam stabilizers includes, without limitation, cocoamine oxide, isononyldimethylamine oxide, n-dodecyldimethylamine oxide, and so forth.

In some example embodiments, if utilized, the foam stabilizer may include between about one- hundredth percent (0.01 %) and about two percent (2%) of the foam (by weight). In certain example embodiments, the foam stabilizer may include between about five-hundredths percent (0.05%) and one percent (1%) of the foam or even between about one-tenth percent (0.1 %) and about a half percent (0.5%) of the foam (by weight).

Components:

In the methods as described herein, the foam forming process may include adding one or more components as additional additives that will be incorporated into the substrate 12. For example, one additional additive that may be added during the formation of the substrates 12 as described herein may be a superabsorbent material(s). Superabsorbent material is commonly provided in a particulate form and, in certain aspects, may include polymers of unsaturated carboxylic acids or derivatives thereof. These polymers are often rendered water insoluble, but water swellable, by crosslinking the polymer with a di- or polyfunctional internal crosslinking agent. These internally crosslinked polymers are at least partially neutralized and commonly contain pendant anionic carboxyl groups on the polymer backbone that enable the polymer to absorb aqueous fluids, such as body fluids. Typically, the superabsorbent particles are subjected to a post-treatment to crosslink the pendant anionic carboxyl groups on the surface of the particle. Superabsorbent materials are manufactured by known polymerization techniques, desirably by polymerization in aqueous solution by gel polymerization. The products of this polymerization process are aqueous polymer gels, i.e., superabsorbent hydrogels that are reduced in size to small particles by mechanical forces, then dried using drying procedures and apparatus known in the art. The drying process is followed by pulverization of the resulting superabsorbent particles to the desired particle size. Examples of superabsorbent materials include, but are not limited to, those described in US7396584 Azad et al., US7935860 Dodge et al., US2005/5245393 to Azad et al., US2014/09606 to Bergam et al., W02008/027488 to Chang et al. and so forth. In addition, in order to aid processing, the superabsorbent material may be treated in order to render the material temporarily non-absorbing during the formation of the foam and formation of the highly-expanded foam. For example, in one aspect, the superabsorbent material may be treated with a water-soluble protective coating having a rate of dissolution selected such that the superabsorbent material is not substantially exposed to the aqueous carrier until the highly-expanded foam has been formed and drying operations initiated. Alternatively, in order to prevent or limit premature expansion during processing, the superabsorbent material may be introduced into the process at low temperatures.

In some example embodiments incorporating superabsorbent material, the superabsorbent material may include between about zero percent (0%) and about forty percent (40%) of the foam (by weight). In certain example embodiments, the superabsorbent material may include between about one percent (1%) and about thirty percent (30%) of the foam (by weight) or even between about ten percent (10%) and about thirty percent (30%) of the foam (by weight).

Other additional agents may include one or more wet strength additives that may be added to the foam or fluid supply 16, 28 in order to help improve the relative strength of the ultra-low density composite cellulosic material. Such strength additives suitable for use with paper making fibers and the manufacture of paper tissue are known in the art. Temporary wet strength additives may be cationic, nonionic or anionic. Examples of such temporary wet strength additives include PAREZ™ 631 NC and PAREZ(R) 725 temporary wet strength resins that are cationic glyoxylated polyacrylamides available from Cytec Industries, located at West Paterson, N.J. These and similar resins are described in US3556932 to Coscia et al. and US3556933 to Williams et al. Additional examples of temporary wet strength additives include dialdehyde starches and other aldehyde containing polymers such as those described in US6224714 to Schroeder et al.; US6274667 to Shannon et al.; US6287418 to Schroeder et al.; and US6365667to Shannon et al., and so forth.

Permanent wet strength agents including cationic oligomeric or polymeric resins may also be used in the present disclosure. Polyamide-polyamine-epichlorohydrin type resins such as KYMENE 557H sold by Solenis are the most widely used permanent wet-strength agents and are suitable for use in the present disclosure. Such materials have been described in the following US3700623 to Keim; US3772076 to Keim; US3855158 to Petrovich et al.; US3899388to Petrovich et al.; US4129528 to Petrovich et al.; US4147586 to Petrovich et al.; US4222921 to van Eenam and so forth. Other cationic resins include polyethylenimine resins and aminoplast resins obtained by reaction of formaldehyde with melamine or urea. Permanent and temporary wet strength resins may be used together in the manufacture of composite cellulosic products of the present disclosure. Further, dry strength resins may also optionally be applied to the composite cellulosic webs of the present disclosure. Such materials may include, but are not limited to, modified starches and other polysaccharides such as cationic, amphoteric, and anionic starches and guar and locust bean gums, modified polyacrylamides, carboxymethylcellulose, sugars, polyvinyl alcohol, chitosan, and the like.

If used, such wet and dry strength additives may include between about one-hundredth percent (0.01%) and about five percent (5%) of the dry weight of cellulose fibers. In certain example embodiments, the strength additives may include between about five-hundredths percent (0.05%) and about two percent (2%) of the dry weight of cellulose fibers or even between about one-tenth percent (0.1 %) and about one percent (1 %) of the dry weight of cellulose fibers.

Still other additional components may be added to the foam so long as they do not significantly interfere with the formation of the highly-expanded stable foam, the hydrogen bonding as between the cellulosic fibers or other desired properties of the web. As examples, additional additives may include one or more pigments, opacifying agents, anti-microbial agents, pH modifiers, skin benefit agents, odor absorbing agents, fragrances, thermally expandable microspheres, foam particles (such as, pulverized foam particles), and so forth as desired to impart or improve one or more physical or aesthetic attributes. In certain example embodiments the composite cellulosic webs may include skin benefit agents such as, for example, antioxidants, astringents, conditioners, emollients, deodorants, external analgesics, film formers, humectants, hydrotropes, pH modifiers, surface modifiers, skin protectants, and so forth.

When employed, miscellaneous components desirably include less than about two percent (2%) of the foam (by weight) and still more desirably less than about one percent (1 %) of the foam (by weight) and even less than about a half percent (0.5%) of the foam (by weight).

In some example embodiments, the solids content, including the fibers or particulates contained herein, desirably include no more than about forty percent (40%) of the foam. In certain example embodiments the cellulosic fibers may include between about one-tenth percent (0.1%) and about five percent (5%) of the foam or between about two-tenths percent (0.2%) and about four percent (4%) of the foam or even between about a half percent (0.5%) and about two percent (2%) of the foam.

The methods and apparatus 10 as described herein may be beneficial for forming one or more components of personal care products. For example, in one example embodiment, the substrates 12 described herein may be an absorbent core for an absorbent article, such as, but not limited to, a diaper, adult incontinence garment, or feminine care product. The substrates 12 as described herein may also be beneficial for using in other products, such as, but not limited to facial tissues, wipes, and wipers.

These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention so further described in such appended claims. EXAMPLE EMBODIMENTS

First example embodiment: A foam forming system, comprising: a particle meter configured for supplying a flow of particles; an eductor configured for directing the flow of particles into a flow of foam; and a flush system disposed downstream of the particle meter and upstream of the eductor on a particle flow path between the particle meter and the eductor, the flush system comprising a particle inlet conduit configured for receiving the flow of particles from the particle meter, an air inlet plenum disposed around the particle inlet conduit and configured for directing a plurality of air flows into the particle inlet conduit, an outlet conduit disposed downstream of the particle inlet conduit and configured for receiving a combined flow of air and particles from the particle inlet conduit, and a fluid inlet plenum disposed around the outlet conduit and configured for directing a plurality of fluid flows into the outlet conduit.

Second example embodiment: The foam forming system of the first example embodiment, further comparing an air inlet plenum disposed around the particle inlet conduit and configured for directing a plurality of air flows into the particle inlet conduit, wherein the outlet conduit is configured for receiving a combined flow of air and particles from the particle inlet conduit.

Third example embodiment: The foam forming system of either the first example embodiment or the second example embodiment, wherein the particle inlet conduit comprises a cylindrical wall extending longitudinally between a top end portion and a bottom end portion, and the air inlet plenum is disposed around the cylindrical wall between the top and bottom end portions of the cylindrical wall.

Fourth example embodiment: The foam forming system of any one of the first through third example embodiments, wherein the air inlet plenum comprises a plurality of ports that are distributed around the particle inlet conduit.

Fifth example embodiment: The foam forming system of any one of the first through fourth example embodiments, wherein the particle inlet conduit comprises a cylindrical wall, and the plurality of ports extend radially through the cylindrical wall.

Sixth example embodiment: The foam forming system of any one of the first through fifth example embodiments, wherein the plurality of ports comprises no less than ten ports, and the plurality of ports are distributed in a ring around the air inlet plenum.

Seventh example embodiment: The foam forming system of any one of the first through sixth example embodiments, wherein a plurality of ports of the air inlet plenum are positioned and oriented for directing the plurality of air flows into the particle inlet conduit in a swirling pattern about a vertical axis. Eighth example embodiment: The foam forming system of any one of the first through seventh example embodiments, further comprising an air valve coupled to the air inlet plenum and configured for regulating an air supply to the air inlet plenum such that the plurality of air flows into the particle inlet conduit create a substantially constant pressure air header around the flow of particles in the particle inlet conduit.

Nineth example embodiment: The foam forming system of any one of the first through eighth example embodiments, wherein the outlet conduit comprises a cylindrical wall extending longitudinally between a top end portion and a bottom end portion, and the fluid inlet plenum is disposed around the cylindrical wall between the top and bottom end portions of the cylindrical wall. Tenth example embodiment: The foam forming system of any one of the first through nineth example embodiments, wherein the fluid inlet plenum comprises a plurality of ports that are distributed around the outlet conduit.

Eleventh example embodiment: The foam forming system of any one of the first through tenth example embodiments, wherein the fluid inlet conduit comprises a cylindrical wall, and the plurality of ports extend radially through the cylindrical wall.

Twelfth example embodiment: The foam forming system of any one of the first through eleventh example embodiments, wherein the plurality of ports comprises no less than ten ports, and the plurality of ports are distributed in a ring around the fluid inlet plenum.

Thirteenth example embodiment: The foam forming system of any one of the first through twelfth example embodiments, wherein the cylindrical wall tapers inwardly between the top and end portions.

Fourteenth example embodiment: The foam forming system of any one of the first through thirteenth example embodiments, wherein a distal end of the particle inlet conduit is disposed within the outlet conduit such that the particle inlet conduit extends past a plurality of ports of the fluid inlet plenum.

Fifteenth example embodiment: The foam forming system of any one of the first through fourteenth example embodiments, wherein the flush system further comprises a drip ring disposed at the distal end portion of the particle inlet conduit and extending radially outward from the particle inlet conduit.

Sixteenth example embodiment: The foam forming system of any one of the first through fifteenth example embodiments, wherein a plurality of ports of the fluid inlet plenum are positioned and oriented for directing the plurality of fluid flows into the outlet conduit in a swirling pattern about a vertical axis. Seventeenth example embodiment: The foam forming system of any one of the first through sixteenth example embodiments, further comprising a fluid meter coupled to the fluid inlet plenum and configured for regulating a fluid supply to the fluid inlet plenum such that the plurality of fluid flows into the outlet conduit are laminar and create a substantially constant pressure fluid header around the flow of particles in the outlet conduit.

Eighteenth example embodiment: The foam forming system of any one of the first through seventeenth example embodiments, wherein the fluid of the plurality of fluid flows comprises one or more of water, foam, or a surfactant.

Nineteenth example embodiment: A flush system, comprising: a particle inlet conduit configured for receiving a flow of particles; an air inlet plenum disposed around the particle inlet conduit and configured for directing a plurality of air flows into the particle inlet conduit; an outlet conduit disposed downstream of the particle inlet conduit and configured for receiving a combined flow of air and particles from the particle inlet conduit; and a fluid inlet plenum disposed around the outlet conduit and configured for directing a plurality of fluid flows into the outlet conduit.

Twentieth example embodiment: A flush system, comprising: a particle inlet conduit configured for receiving a flow of particles; an outlet conduit disposed downstream of the particle inlet conduit and configured for receiving the flow of particles from the particle inlet conduit; and a fluid inlet plenum disposed around the outlet conduit and configured for directing fluid into the outlet conduit such that the fluid coats a surface of the outlet conduit with liquid from the fluid.

Twenty-first example embodiment: A foam forming system, substantially as herein described. Twenty-second example embodiment: A flush system, substantially as herein described.

Claims

What Is Claimed:

1 . A foam forming system, comprising: a particle meter configured for supplying a flow of particles; an eductor configured for directing the flow of particles into a flow of foam; and a flush system disposed downstream of the particle meter and upstream of the eductor on a particle flow path between the particle meter and the eductor, the flush system comprising a particle inlet conduit configured for receiving the flow of particles from the particle meter, an outlet conduit disposed downstream of the particle inlet conduit and configured for receiving the flow of particles from the particle inlet conduit, and a fluid inlet plenum disposed around the outlet conduit and configured for directing a plurality of fluid flows into the outlet conduit.

2. The foam forming system of claim 1 , further comparing an air inlet plenum disposed around the particle inlet conduit and configured for directing a plurality of air flows into the particle inlet conduit, wherein the outlet conduit is configured for receiving a combined flow of air and particles from the particle inlet conduit.

3. The foam forming system of claim 2, wherein the particle inlet conduit comprises a cylindrical wall extending longitudinally between a top end portion and a bottom end portion, and the air inlet plenum is disposed around the cylindrical wall between the top and bottom end portions of the cylindrical wall.

4. The foam forming system of claim 2, wherein the air inlet plenum comprises a plurality of ports that are distributed around the particle inlet conduit.

5. The foam forming system of claim 4, wherein the particle inlet conduit comprises a cylindrical wall, and the plurality of ports extend radially through the cylindrical wall.

6. The foam forming system of claim 4, wherein the plurality of ports comprises no less than ten ports, and the plurality of ports are distributed in a ring around the air inlet plenum.

7. The foam forming system of claim 2, wherein a plurality of ports of the air inlet plenum are positioned and oriented for directing the plurality of air flows into the particle inlet conduit in a swirling pattern about a vertical axis.

8. The foam forming system of claim 2, further comprising an air valve coupled to the air inlet plenum and configured for regulating an air supply to the air inlet plenum such that the plurality of air flows into the particle inlet conduit create a substantially constant pressure air header around the flow of particles in the particle inlet conduit.

9. The foam forming system of claim 1 , wherein the outlet conduit comprises a cylindrical wall extending longitudinally between a top end portion and a bottom end portion, and the fluid inlet plenum is disposed around the cylindrical wall between the top and bottom end portions of the cylindrical wall.

10. The foam forming system of claim 1 , wherein the fluid inlet plenum comprises a plurality of ports that are distributed around the outlet conduit.

11. The foam forming system of claim 10, wherein the fluid inlet conduit comprises a cylindrical wall, and the plurality of ports extend radially through the cylindrical wall.

12. The foam forming system of claim 10, wherein the plurality of ports comprises no less than ten ports, and the plurality of ports are distributed in a ring around the fluid inlet plenum.

13. The foam forming system of claim 10, wherein the cylindrical wall tapers inwardly between the top and end portions.

14. The foam forming system of claim 1 , wherein a distal end of the particle inlet conduit is disposed within the outlet conduit such that the particle inlet conduit extends past a plurality of ports of the fluid inlet plenum.

15. The foam forming system of claim 14, wherein the flush system further comprises a drip ring disposed at the distal end portion of the particle inlet conduit and extending radially outward from the particle inlet conduit.

16. The foam forming system of claim 1, wherein a plurality of ports of the fluid inlet plenum are positioned and oriented for directing the plurality of fluid flows into the outlet conduit in a swirling pattern about a vertical axis.

17. The foam forming system of claim 1 , further comprising a fluid meter coupled to the fluid inlet plenum and configured for regulating a fluid supply to the fluid inlet plenum such that the plurality of fluid flows into the outlet conduit are laminar and create a substantially constant pressure fluid header around the flow of particles in the outlet conduit.

18. The foam forming system of claim 1, wherein the fluid of the plurality of fluid flows comprises one or more of water, foam, or a surfactant.

19. A flush system, comprising: a particle inlet conduit configured for receiving a flow of particles; an air inlet plenum disposed around the particle inlet conduit and configured for directing a plurality of air flows into the particle inlet conduit; an outlet conduit disposed downstream of the particle inlet conduit and configured for receiving a combined flow of air and particles from the particle inlet conduit; and a fluid inlet plenum disposed around the outlet conduit and configured for directing a plurality of fluid flows into the outlet conduit.

20. A flush system, comprising: a particle inlet conduit configured for receiving a flow of particles; an outlet conduit disposed downstream of the particle inlet conduit and configured for receiving the flow of particles from the particle inlet conduit; and a fluid inlet plenum disposed around the outlet conduit and configured for directing fluid into the outlet conduit such that the fluid coats a surface of the outlet conduit with liquid from the fluid.