KR20020081486A - Co-apertured Systems for Hygienic Products - Google Patents

Abstract

Provided is a system for hygiene products having a cover layer, an intake / distribution layer and an absorbent core, wherein at least the cover layer and the intake / distribution layer are co-perforated. Combining these improvements into an integrated absorption system allows for successful achievement of variable flow management and a successful balance between intake and cover detachment properties. As a result, many intake performances are improved and the cover surface is clean and dry during use.

Description

Co-apertured Systems for Hygienic Products

Personal protective articles include items such as diapers, training pants, feminine hygiene products such as sanitary napkins, panty liners and tampons, incontinence clothing and devices, bands and the like. The most basic design of all the above mentioned articles usually includes a bodyside liner (cover material), an outer cover (also called a baffle) and an absorbent core disposed between the bodyside liner and the outer cover.

Personal protective products should have them to quickly receive fluids and reduce the likelihood of leakage out of the product. The product must be flexible and have a satisfactory feel to the skin and must not be wrinkled, distorted or wound on the user, even after liquid excretion, which makes the wearer uncomfortable. Unfortunately, existing products have met many of the above criteria to varying degrees, but still many have not been met.

In particular, feminine hygiene products for long term (ie overnight) use are exposed to higher and more variable flow rates and fluid loads than those intended for regular or shorter periods of use. Thus, products intended for overnight use must have the ability to absorb and contain gushes and sudden large flows as well as continuous small flows over the life of the product. Continuous flow excretion in feminine hygiene products has been found to be on average 1 ml / hr but higher, in fact being variable in speed rather than continuous or constant and may be stopped during the cycle. "Ejection flow" is defined as abrupt mass flow and occurs at a flow rate of 1 ml / sec or less. During the ejection, 1-5 ml of fluid is released from the body onto the product. The term "continuous flow" is used to define all flows outside the definition of the ejection flow.

The sum of the continuous and jet flow states is variable flow. In essence, a "variable flow" is defined as a continuous flow where intermittent jet flow occurs. 1 illustrates the difference between variable flow (lozenge) and continuous flow (square) over the lifetime of a single product, with flow rate in g / hr on the y-axis and time in hours on the x-axis One graph. The problem of handling ejection and continuous flow is called variable flow management, and not only a small amount of continuous flow (1-2 ml / hr) over the life of the product, but also a large number of ejections or sudden mass flow excretion (total volume 1-5 ml). Is defined as the ability to absorb and contain 1 ml / sec.

The ultimate challenge for the product is that it must be able to handle the ejection (sudden flow) after the product is contaminated and the absorption system is partially or fully saturated.

Many women's protective cover materials have low z-direction conductivity, low surface energy, low void volume, and due to their two-dimensional structure there is little gap between the absorbent core and the user. As a result, these covers have slow and incomplete intake, high rewet, and high surface contamination. In addition, typical intakes or acquisition layers are low density and high volume structures that are ideal for fast fluid intakes, but these structures usually have low capillary properties and due to their overall fiber properties, the fluid does not adequately desorb from the cover material to spread and Surface wetting occurs. Materials that improve cover detachment are usually denser and have high capillary properties, but these materials inherently retard fluid intakes because of their low volume and low z-direction permeability.

There is a need for a system that is designed to promote rapid intake, to keep clean and dry, and to receive fluid at an appropriate rate. There is also a need for a system that further allows fluid to be absorbed into a particular absorbent layer.

It is therefore an object of the present invention to provide such a system. It is a further object of the present invention to provide a design for a feminine hygiene product, in particular comprising the system described above for medium to high fluid loadings.

<Overview of invention>

The object of the present invention is achieved by a system having a cover layer, an intake / distribution layer and an absorbent core, wherein at least the cover layer and the intake / distribution layer are co-perforated. Other layers may also be present including a surge layer and a propagation delay layer. The cover may be a film or nonwoven made from a thermoplastic polymer. The intake / distribution layer is preferably a nonwoven fabric, more preferably produced by an airlaying process. Surge layers and propagation delay layers are generally nonwovens of various wettability, pore size, permeability and fiber denier. The absorbent core can be made from pulp, superabsorbent or various other absorbents. The system of the present invention improves the absorption of multiple excretion allowing fluid storage in certain layers, which provides a clean and dry cover surface during use. These functional properties are provided through improved material technology and product structure.

The present invention relates to a system for absorbent hygiene personal protective articles, in particular feminine hygiene products. Such products should not rapidly spread and retain viscous fluids outside the product which may contaminate the wearer's clothing.

1 is a graph of variable flow (lozenge) and continuous flow (square) over the lifetime of a single product, where flow velocity volume is expressed in g / hr on the y-axis and time in hours on the x-axis .

2 is a diagram of a 7.4 drill / cm 2 pin drill pattern using pins of 2.06 mm diameter.

3 is a view of a pin perforation pattern of 2.5 perforations / cm 2 with the same pin diameter as in FIG.

4 is a schematic diagram of a speed block device suitable for use in measuring the fluid intake time of a material or material system.

5 is a schematic diagram of an absorption system having perforations throughout the cover and intake / distribution layer.

6 is a schematic of a co-perforated absorption system similar to that of FIG. 5 except that no additional layer of material between the cover and the intake / distribution layer is included.

7, 8, 9, 10, 11, 12 and 13 are examples of zoned co-perforation patterns that can be used in the practice of the present invention.

Justice

As used herein, the term "nonwoven or web" refers to a matrix of individual fibers or yarns that are embedded in a manner that is not identifiable as in a knitted fabric. Nonwovens or webs have been formed from many processes, such as, for example, meltblowing processes, spunbonding processes, and bonded carded web processes. The basis weight of the nonwoven is usually expressed in ounces per square yard (osy) or grams per square meter (gsm), and useful fiber diameters are usually expressed in microns. (Note that to convert osy to gsm, multiply osy by 33.91).

"Spunbonded fibers" refers to small diameter fibers formed by extruding molten thermoplastic material as filaments from a plurality of fine capillaries of spinneret. Such a process is disclosed, for example, in US Pat. No. 4,340,563 (Appel et al.). The fibers may also have a shape such as described in US Pat. No. 5,277,976 (Hogle et al.), For example, describing fibers having conventional out-of-frame shapes.

A "bonded carded web" is obtained from staple fibers sent through a combing or carding unit that separates or unraveles staple fibers and aligns them in a machine direction to form a generally machine-oriented fibrous nonwoven web. Shows the web produced. The materials may be bonded together by methods including point bonding, through air bonding, and the like.

"Airlaying" is a well known process that can form fibrous nonwoven layers. In the airlaying process, bundles of small fibers having a typical length of about 3 to about 19 millimeters (mm) are separated and entrained in an air supply and are then deposited onto a forming screen with the aid of a vacuum feeder. The randomly deposited fibers are then adhered to each other using, for example, hot air or a spray adhesive. Airlaying is taught, for example, in US Pat. No. 4,640,810 (Laursen et al.).

As used herein, the term “coform” refers to a process in which at least one meltblown diehead is arranged near a chute where other materials are added through the web while the web is being formed. The other material may be pulp, superabsorbent or other particles, natural polymers (eg rayon or cotton fibers) and / or synthetic polymers (eg polypropylene or polyester) fibers, for example Wherein the fibers may be staple length. The coform process is shown in commonly assigned US Pat. Nos. 4,818,464 (Lau) and 4,100,324 (Anderson et al.). Webs made by the coform process are generally referred to as coform materials.

"Co-perforation" refers to a perforation process as well as a perforated material, in which two or more materials are perforated together. The perforations extend from the top of the material to the base and are essentially aligned with each other. Co-perforation can connect the materials temporarily or permanently through entanglement, physical or chemical bonding. Co-punching the layers can be carried out at ambient or elevated temperature. Higher temperatures aid in material adhesion and form cleaner pores. One process of co-perforation involves pressing the pins through the various layers by feeding the various layers together through a nip formed by two anti-rotating rollers, one of which has a pin to create a perforation. By. The perforations can be, for example, from 0.5 mm to 5 mm in size using pin densities of 1 to 15 per minute / cm 2, resulting in perforations with an area less than 19.6 mm 2 and an open area of about 2 to about 25%. Co-perforation can be performed as a separate "offline" operation or as part of a larger conversion operation (in-line), depending on process economics and equipment utility. Examples of some co-perforation patterns for feminine hygiene pads can be seen in FIGS. 7-13.

A "delivery delay layer" refers to a material that slows fluid transfer between other adjacent layers but does not hold a substantial amount of fluid itself.

"Personal protective product" means diapers, training pants, disposable swimwear, absorbent underpants, adult incontinence products, feminine hygiene products, wound protection items such as bands and other articles.

"Women's hygiene product" means a sanitary napkin or pad and pantyliner.

"Target area" refers to the area of the personal protective product that the wearer would normally excrete while wearing the product.

Test Methods

Material caliper (thickness) :

Caliper of material is a measure of thickness and STARRET at 0.05 psi (3.5 g / cm 2) Measured in millimeters using a -type bulk tester. Samples are cut into 4 "x 4" (10.2 cm x 10.2 cm) squares, five samples are tested and the results averaged.

Density :

The density of the material is obtained by dividing the weight per unit area of the sample (gsm) by 0.05 psi (3.5 g / cm 2) by the caliper of the material (in mm) and multiplying the result by 0.001 to gram / cubic centimeter (g / cc) Calculate by switching. A total of three samples are evaluated and averaged against the density values.

Preparation of mock menses simulant :

The artificial menstrual fluid used in the test was divided from blood and egg whites into blood and red blood cells according to U.S. Patent No. 5,883,231, and the whites into viscous and dilute portions (where "viscous" is the viscosity after homogenization). Means more than about 20 centipoise at 150 sec ⁻¹ ), and the viscous egg whites were combined with plasma and thoroughly mixed, finally adding red blood cells and again thoroughly mixing. A more detailed procedure is as follows:

Blood (defibrinated pig blood in this example) is separated by centrifugation at 3000 rpm for 30 minutes, but other methods or speeds and times may be used if effective. Plasma is separated and stored separately, the light yellowish brown layer is removed and discarded, and the aggregated red blood cells are also stored separately. It should be noted that blood must be processed in several ways so that it can be processed without coagulation. Various methods are known to those skilled in the art, such as by defibrating blood, adding anticoagulants, and the like to remove coagulated fiber material. Blood must not coagulate in order to be useful, and any method of achieving this without damaging plasma and red blood cells is allowed.

Jumbo eggs are separated, discarded yolks and egg yolks, retain whites. The whites are filtered through a 1,000-micron nylon mesh for about 3 minutes to separate the viscous and thin portions and the thinner portions are discarded. The viscous portion of the whites retained on the mesh is collected and placed into a 60 cc syringe, which is then placed on a programmable syringe pump and homogenized by pushing and refilling the contents five times. The amount of homogenization is controlled by a syringe pump speed of about 100 ml / min and a tube inner diameter of about 0.12 inches. After homogenization, the viscosity of the viscous whites is about 20 centipoise at 150 sec ^-1 , which is then placed in a centrifuge and rotated to remove debris and bubbles at about 3000 rpm for about 10 minutes.

After centrifugation, the viscous homogenized white egg containing ovamucin was 300 cc FENWAL using a syringe. Add to transfer pack container. FENWAL followed by 60 cc of pig plasma Add to delivery pack container. FENWAL The transfer pack container is clamped and all bubbles are removed and placed in a Stomacher laboratory blender, where they are blended for about 2 minutes at normal (or medium) speed. Followed by FENWAL The transfer pack container is removed from the blender and 60 cc of porcine red blood cells are added and the contents are mixed by hand kneading for about 2 minutes or until the contents appear homogeneous. The hematocrit of the final mixture should show an erythrocyte content of about 30% by weight and generally should be within at least 28-32% by weight relative to the artificial menstrual blood prepared according to this example. The amount of whites is about 40% by weight

Ingredients and equipment used to make artificial menstrual blood are readily available. The sources for the items used are listed below, but of course other sources may be used if they are approximately equivalent.

Blood (pig): Cocalico Biologicals, Inc., 449 Stevens Rd., Reamstown, PA 17567, (717) 336-1990.

FENWAL Delivery pack container, 300 ml, with coupler, code 4R2014: Baxter Health Care Corporation, Fenwal Division, Deerfield, IL 60015.

Harvard Apparatus Programmable Syringe Pump Model No. 55-4143: Harvard Apparatus, South Natick, MA 01760.

Stomacher 400 Laboratory Blend Model No. BA 7021, Serial No. 31968: Seward Medical, London, England, UK.

1000 micron mesh, item number CMN-1000-B: Small Parts, Inc., PO Box 4650, Miami Lakes, FL 33014-0650,1-800-220-4242.

Hemata Stat-ll Hemocrite Measuring Device, Serial No. 1194Z03127: Separation Technology, Inc., 1096 Rainer Drive, Altamont Springs, FL 32714.

Speed Block Intake Test :

This test is used to measure the intake time of a known amount of fluid into a material and / or material system. The test apparatus consists of a transparent, preferably acrylic speed block 10 as shown in FIG. 4. The speed block 10 has a width of 3 inches (76.2 mm) and a depth of 2.87 inches (72.9 mm) (into the page), and a height of 0.125 inches (3.2 mm) and a width of 0.886 that protrude further from the main body of the speed block 10. The overall height is 1.125 inches (28.6 mm), including the central region 19 on the base of the speed block 10 of inches (22.5 mm). The speed block 10 has a capillary tube 12 with an inner diameter of 0.186 inches (4.7 mm) extending diagonally down at an angle of 21.8 ° from horizontal to the centerline 16 on one side 15. The capillary tube 12 can be made by drilling a hole of the appropriate size at an appropriate angle starting from the side 15 of the speed block 10 at the point 0.726 inches (18.4 mm) above the base of the speed block 10. ; However, the starting point of the drilled hole in the side 15 should be blocked afterwards to prevent leakage of the test fluid. Top hole 17 is 0.312 inches (7.9 mm) in diameter and 0.625 inches (15.9 mm) in depth, crossing capillary tube 12. The upper hole 17 is perpendicular to the top of the speed block 10 and centered 0.28 inches (7.1 mm) from the side 15. The upper hole 17 is a hole in which the funnel 11 is placed inside. The center hole 18 is for the purpose of viewing the advancement of the test fluid and is actually oval into the plane of FIG. 4. The center hole 18 is centered in the width direction on the speed block 10 and has a center of a 0.315 inch (8 mm) diameter semicircle that has a bottom hole width of 0.315 inch (8 mm) and constitutes egg-shaped ends. Is 1.50 inches (38.1 mm) from center to center. For ease of observation, the oval is 0.44 inches (11.2 mm) wider from the base of the speed block 10 to be 0.395 inches (10 mm) wide and 1.930 inches (49 mm) long. The perforations can also make the upper hole 17 and the center hole 18.

10.2 cm x 10.2 cm (4 "x 4") of the absorber 14 and the cover 13 are die cut. Specific covers will be described in specific embodiments. Absorbents used for this study are standard and unless otherwise indicated consist of 250 g / m 2 airlaid made of 90% CR-0054 (US Alliance Pulp Mills, Coosa, Alabama) and 10% KoSa T-255 binder. The total density for this system was 0.14 g / cc. The cover 13 was placed over the absorbent material 14 and the speed block 10 was placed on top of both materials. 2 ml of simulated menstrual blood was transferred into the test apparatus funnel 11 and the timer started to count. Fluid traveled from funnel 11 to channel 12 where it is delivered to a material or material system. The timer was stopped when all fluid was absorbed into the material or material system when observed from the chamber in the test apparatus. Intake times were recorded for known amounts of known fluids for the given materials or material systems. This value is a measure of the absorbency of the material or material system. In general, it was repeated 5 to 10 times and the average intake time was measured.

Rewet test

This test is used to measure the amount of fluid that will return to the surface when a load is applied. The amount of fluid returning through the surface is called the "rewet" value. The greater the amount of fluid returning to the surface, the greater the "rewet" value. Lower rewet values are associated with drier material, and therefore drier product. When considering rewetting, three properties are important: (1) intake rate (because the fluid can be rewet if the material / system does not have a good intake rate), (2) the ability of the absorbent to hold the fluid. (The less absorbent is used for rewetting if the fluid retains more fluid), and (3) the flowback (the less rewet if the cover prevents the fluid from returning through the cover more).

Evaluate the cover system where the absorbent remains constant to remove variable (2) from consideration. This left only variables (1) intake and (3) backflow in consideration.

10.2 cm x 10.2 cm (4 "x 4") pieces of absorber and cover were die cut. The absorbers used in these studies consisted of 250 gsm airlaid made as a standard and made of 90% CR-0054 (US Alliance Pulp Mills, Coosa, Alabama) and 10% KoSa T-255 binder. Total density for this system was 0.14 g / cc unless otherwise indicated. The cover was placed on the absorbent material and the speed block was placed on top of both materials. 2 ml of simulated menstrual blood was delivered to a speed block device and absorbed into a 4 "x 4" sample of cover material placed on top of a 4 "x 4" absorbent piece. The fluid was interacted with the system for 1 minute with the speed block on top of the material. The material system cover and absorbent material are placed on a fluid filled bag. The piece of blotter paper is weighed and placed on the material system. The bag is traversed vertically until it comes in contact with the acrylic plate thereon, forcing the entire material system against the pressing side of the plate first. The system is pressed against the acrylic plate until a total pressure of 1 psi is applied. The pressure is held fixed for 3 minutes, after which the pressure is removed and the blotter paper is weighed. The blotter retains all fluid transferred from the cover / absorber system to the blotter. The difference in weight between the original blotter and the blotter after the test is known as the "rewet" value. In general, this test was repeated 5 to 10 times and the average rewet was measured.

Triple Intake Test Procedure :

The purpose of this test is to allow the fluid to be distributed in the material (s) between the excretion, and the materials and / or materials, composites at the intake rate when three abrupt fluid excretions (eruptions) are applied. Or to measure the difference between systems of material composites. The material to be tested is prepared in the same manner as in the speed block intake test described above. Two 2 mL simulated menstrual blood are delivered to the material via a velocity block. After 9 minutes the speed block is removed and each layer is weighed and the weight recorded. This step is repeated for a total of three excretions, after which a rewet test as described above is performed and the value recorded. The fluid load in each component is calculated by subtracting the weight after excretion from the weight before excretion. Excretion time is a direct measure of the time for absorption. Lower values of intake time indicate more absorbent samples, and higher values of intake time indicate less absorbent samples. Three samples should be evaluated for each material.

Fluid distribution test :

This test is designed to measure the fluid distribution in the various layers that make up personal protective products, especially feminine hygiene products. Each layer of material in the sample to be tested should be weighed and the weight before the test recorded. The material to be tested is laid flat and an hourglass shaped plate is placed on the material. The plate is preferably acrylic, having a length of 21.5 cm, a width of 8.7 cm, a weight of 230 g, and a 3 mm wide hole in the center thereof. The plate is loaded with an additional 800 g of weight distributed as evenly as possible on its surface. Once the sample is ready for testing, 7 ml of simulated menstrual blood is delivered to the sample through the hole at a uniform rate over 1 hour. One method of providing simulated menstrual blood to a sample is to use a Harvard Apparatus Model 55-4143 pump and plastic tubes, but similar methods known to those skilled in the art may be used. After time, the plate is removed and the layers are weighed. The difference in weight between the dry and wet layers is the amount of simulated menstrual blood absorbed in each layer. The percentage of fluid retained in each layer can then be calculated. Three samples should be evaluated for each material.

<Detailed Description of the Invention>

In one aspect, the present invention relates to a composite for use in feminine hygiene pads in which the cover layer and intake / distribution layer of the composite are co-perforated. The layers are a cover, intake / distribution layer, optional surge layer, optional transfer retardation layer and absorbent core. Fabrics used in the practice of the present invention can be produced by a variety of processes including airlaying, spunbonding, meltblowing, carding, coform and foaming processes, but spuns for airlaying and delivery retardation layers for intake / distribution layers. Bonding is preferred. Various layers can be made from synthetic polymers and natural fibers. Polyolefins such as polyethylene and polypropylene are particularly preferred because of cost.

5 shows one embodiment of the present invention. In Fig. 5, the outer cover 5 is the outermost part of the product. The absorbent core 4 is arranged close to the outer cover 5. An optional transfer retardation layer 3 is adjacent to the absorbent core 4. The cover 1 and the intake / distribution layer 2 are co-perforated as indicated by the cone 6.

FIG. 6 shows another embodiment of the invention similar to FIG. 5, wherein another layer (s) 7 are inserted between cover layer 1 and intake / distribution layer 2. The additional layer 7 may for example be a surge layer.

It is important that the cover draws the waste quickly into the product and has a smooth surface. Many materials provide such intake properties. These are films, nonwovens and film / nonwoven laminates, nonwoven / nonwoven laminates, bonded fiber spunbond fabrics, creped spunbond fabrics, airlaid fabrics, bonded carded webs, spunlaces Woven fabrics, embossed nonwovens, and the like. Many cover materials that may be unsuitable at first may be made suitable through the use of local chemical treatment and mechanical processing. Any material that, when combined with the absorbent core, allows for rapid intake, low contamination, low rewetting and low fluid retention under all flow conditions, will be suitable for use in the practice of the present invention. These materials may also include other additives to improve softness or to deliver skin health benefits.

The intake / distribution layer is mechanically and chemically derived from various fibers and mixtures of fibers, including synthetic and natural fibers, including softened pulp, staple fibers, slivers, meltblown and spunbond fibers, superabsorbents and the like. Can be prepared. The fibers in the webs described above may be made from fibers of the same or different diameters and may be of different shapes, such as five branches, three branches, ovals, circles, and the like. Intake / distribution layers can be prepared by a number of methods including airlaying, hydroentangling, bonding and carding, and coforming, but airlaying is preferred. The density of the intake / distribution layer may be about 0.06 to 0.19 g / cc and the basis weight may be about 100 to 300 gsm.

The optional surge layer serves to absorb the flow of many sudden liquids. Surge control materials are provided to quickly receive incoming feces and to absorb, retain, channel or otherwise manage the liquid so that it does not leak out of the article. Surge control is usually provided by fluff pulp in the absorbent article or by a highly permeable nonwoven layer, such as spunbond fabrics or bonded carded webs.

The optional delivery retardation layer can also be made from a variety of fibers of various shapes and sizes and can alternatively be a film. The transfer retardation layer can be prepared according to many processes, such as spunbonding, carding, meltblowing, and film formation, but spunbonding is preferred. The purpose of the delivery retardation layer is to slow the fluid passage from the intake / distribution layer to the absorbent layer, with both sides adjacent to the delivery retardation layer.

Absorbent core or retention layer materials may be prepared from materials or materials known in the art to absorb liquids, as well as any other that may be developed for this purpose. Examples include fast or slow superabsorbents, pulp and mixtures thereof. The mixture of superabsorbent and pulp used as retentate may be used in a weight ratio of about 100/0 to 0/100, more particularly about 80/20 to 20/80. Absorbent cores suitable for use in the present invention usually have a density of about 0.05 to 0.20 g / cc and a basis weight of 150 to 500 gsm. There may be one or more layers comprising the absorbent core. The absorbent core also usually has some kind of binder to hold the components together. Typical binders include bonded fibers, thermally activatable adhesive powders, and liquid binders.

Synthetic fibers are polyamide, polyester, rayon, acrylic, superabsorbent, LYOCELL And those made from regenerated cellulose and any other suitable synthetic fiber known to those skilled in the art. Synthetic fibers may also include kosmotropes for product degradation.

Many polyolefins are available for fiber production, for example ASPUN from Dow Chemical. 6811A linear low density polyethylene, 2553 LLDPE and polyethylene such as 25355 and 12350 high density polyethylene are such suitable polymers. The melt flow rates of the polyethylene are about 26, 40, 25 and 12, respectively. Fiber-forming polypropylene is ESCORENE of Exxon Chemical Company PD 3445 polypropylene and PF-304 from Montell Chemical Co. Many other polyolefins are commercially available.

Natural fibers include wool, cotton, flax, hemp and wood pulp. Wood pulp includes standard softwood fluffing grades such as CR-1654 (US Alliance Pulp Mills, Coosa, Alabama). The pulp can be modified to improve the inherent characteristics of the fibers and their processability. Curls can be imparted to the fiber by methods including chemical treatment or mechanical twisting. Curls are usually imparted before crosslinking or stiffness. The pulp may be a crosslinking agent such as formaldehyde or derivatives thereof, glutaraldehyde, epichlorohydrin, methylolated compounds, eg urea or urea derivatives, dialdehydes such as maleic anhydride, nonmethylolated urea derivatives It can be stiffened using citric acid or other carboxylic acids. Some of these agents are less desirable than others because of environmental and health concerns. Pulp can also be stiffened by the use of caustic treatments such as heat or masher. Examples of these types of fibers include NHB416 (available from Weyerhaeuser Corporation (Tacoma, WA)), which is a chemically crosslinked southern softwood pulp fiber that enhances wet modulus. Other useful pulp are debonded pulp (NF405) and non-bonded pulp (NB416) (also from Weyerhaeuser). HPZ3 from Buckeye Technologies, Inc. (Memphis, TN) has a chemical treatment that hardens curls and twists in addition to imparting dry and wet stiffness and elasticity added to the fibers. Another suitable pulp is Buckeye HP2 pulp and another is IP Supersoft (International Paper Corporation). Suitable rayon fibers are 1.5 denier Merge 18453 fibers (Acordis Cellulose Fibers Incorporated, Axis, Alabama).

Superabsorbents useful in the present invention may be selected from categories based on chemical structure and physical form. These include low gel strength, superabsorbents with high gel strength, surface crosslinked superabsorbents, uniformly crosslinked superabsorbents, or superabsorbents with varying crosslink density throughout the structure. Superabsorbents can be based on chemicals, including but not limited to acrylic acid, iso-butylene / maleic anhydride, polyethylene oxide, carboxy-methyl cellulose, polyvinyl pyrrolidone, and polyvinyl alcohol. Superabsorbents can vary from slow to fast. Superabsorbents may be in the form of foams, macroporous or microporous particles or fibers, and may have a fluff or fibrous coating or appearance. The superabsorbent may be in the form of ribbons, particles, fibers, sheets or films. Superabsorbents can be of various lengths and diameter sizes and distributions. Superabsorbents can be of varying degrees of neutralization. Neutralization occurs through the use of counter ions such as Li, Na, K, and Ca.

The material of the present invention may comprise a superabsorbent of the aforementioned type. Examples of these types of superabsorbents are available from Stockhausen Company (Greensboro, NC) and FAVOR It is designated as 880. Camelot Technologies Ltd. An example of these types of superabsorbents obtained from Alberta, Canada is FIBERDRI. 1241 and FIBERDRI It is designated as 1161. Technical Absorbents, Ltd. Examples of these types of superabsorbents obtained from Grimsby, UK are OASIS 101 and OASIS It is designated as 111. Other examples included in these types of superabsorbents are from Chemdall International (Arlington Heights, III) and FLOSROB 60 LADY It is designated as. Another example included in these types of superabsorbents is obtained from Sumitomo Seika (Japan) and designated as SA60N Type 2.

Binders commonly used in these structures help to provide mechanical integrity and stabilization. The binder includes fibers, liquids or other binder means that can be thermally activated. Preferred fibers for inclusion are those having relative melting points, such as polyolefin fibers. Lower melting polymers provide the ability to bond the fabric together at the fiber intersection upon application of heat. In addition, fibers with lower melting points, such as conjugate fibers and bicomponent fibers, are suitable for the practice of the present invention. Fibers having lower melting polymers are generally referred to as "fusible fibers". "Lower melting point" means that the glass transition temperature is less than about 175 ° C. It should be noted that the texture of the absorbent web may vary from soft to stiff through the choice of the glass transition temperature of the polymer. Exemplary binder fibers include conjugate fibers of polyolefins, polyamides, and polyesters. Three suitable binder fibers are KoSa Inc. Sheath core bonded fibers available under the trade names T-255 and T-256 or Copolyester from Charlotte, North Carolina, although many suitable binder fibers are known to those skilled in the art and are associated with Chisso and Fibervisions LLC (Wilmington, DE). Available by many such manufacturers. KoSa has developed suitable co-polyester binder fibers for shell core applications and is known under the name T254 (low melting point CoPET). Suitable liquid binders are KYMENE 557LX (available from Fibervisions LLC). Another suitable liquid binder is the trade name Dur-O-Set from National Starch and Chemical Company (Bridgewater, New Jersey). ELITE Series (ELITE 33 and ELITE Ethylene vinyl acetate emulsion polymer commercially available). Air Products Polymers and Chemicals has another suitable binder fiber under the trade name AIRFLEX. Marketed as.

Once manufactured, the web must be properly stabilized and hardened to retain its shape. Inclusion of a sufficient amount of soluble fiber and subsequent thermal adhesion is the preferred method for obtaining proper stabilization. The method is believed to allow for proper adhesion on the surface as well as in the center of the thick material.

As mentioned above, at least the cover layer and the intake / distribution layer of the system are co-perforated, thus creating a structure that allows for rapid intake of the fluid and absorption on the designed absorbent layer. The other layers may optionally be co-perforated with each other or co-perforated with the cover layer and the intake / distribution layer or not at all. Co-perforating the cover with the absorption system improves material permeability, reducing the fluid intake rate. Making voids through all the layers also creates the necessary passages for the fluid to be absorbed in the desired layer under high or ejection flow conditions. This provides a balance in fluid absorption in the XY and Z directions, where the Y-direction is towards the rear of the product, the Z-direction enters the interior of the product perpendicular to the Z-direction, and the X-direction is Perpendicular to both Z directions. Simultaneous perforation of layers also provides a greater degree of structural integrity to the system.

The shape of the various layers is not considered important to the success of the present invention. However, the airlaid intake / distribution layer and absorbent core or retention layer also have a reduced dimension rectangular strip geometry that prevents fluid wicking to the pad edges when used, for example, in feminine hygiene products. It should be understood that may include. The retention layer shape may be the same or different than the other layers and may be rectangular, hourglass, track or other shapes. In addition, embossing may be added to the retention layer and / or other layers to improve the integrity of the layer. Co-perforation may only be performed at the center of the product to improve the functionality of the product in the target area and visually inform the user of the remaining life of the product. Alternatively, the product may be co-perforated over its entire dimension or in another local area.

The cover can be treated with a surfactant to improve its wettability. Such surfactants may be placed across the entire pad, in particular regions or zones, or may be mixed internally into the fiber. In this last embodiment, when the material is perforated using hot fins, the surfactant “swells” or moves towards the outer surface of the fiber, creating a wettable zone surrounding the perforation to improve the intake properties of the material. Enough heat should be applied. Examples of chemicals that can be used on the material are trademarks AHCOVEL (ICI Surfactants, Wilmington, Delaware), GLUCOPON (Henkel Corporation, Chemical's Group, Cincinnati, Ohio), PLURONICS (BASF, Germany), TRITON X-102 (Union Carbide Corporation, Danbury, Connecticut) and MASIL SF-19 Commercially available from (PPG Industries, Inc., Gurnee, Illinois) or combinations thereof, but is not limited thereto.

The optional fluid delivery delay layer according to the present invention is designed to enhance the distribution in the x-y plane by delaying fluid delivery from the intake / distribution layer to the retention layer. The delivery delay layer allows fluid to be delivered to the retention layer when high pressure, high flow rates or high saturation levels occur. Such controlled delivery mechanisms can lengthen the contamination pattern in the retentive layer, help prevent oversaturation in the excretory area, and provide the wearer with a visual signal indicating that the remaining life of the product is reduced.

The delivery delay layer provides a permeability and wettability gradient by preventing intimate contact between the two layers between the intake / distribution layer and the underlying retention layer. Thus, the delivery retardation layer should have relatively low permeability and wettability, thus promoting fluid lateral fluid distribution in the intake / distribution layer under continuous flow conditions to regulate fluid motion in the Z-direction. However, under ejection flow conditions, the perforations in the delivery retardation layer allow the fluid to pass immediately to the underlying retention layer. The wettability of the delivery delay layer can be modified by a topical chemical treatment agent as described above for the cover layer.

Another embodiment of the present invention may include co-perforation of multiple layers that may constitute an absorbent core, allowing fluid to migrate to and absorb the desired product layers and to improve fluid absorption. This increases the absorber utilization efficiency and forms different absorption patterns.

The following examples were run and tested to determine the amount of improvement provided by examples of systems according to the invention.

<Example 1>

The layers described below were cut into 4 "x 4" pieces and placed on top of each other in the order described using no adhesive.

Cover Layer: 20.3 gsm (0.6 osy) ESCORENE PD-3445 Polypropylene Spunbond Nonwoven with 3.5 dpf Fiber. Topical Applied 0.3% by volume AHCOVEL Treated with surfactant.

Intake / distribution layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 250 gsm, density 0.14 g / cc.

Delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE PD-3445 Polypropylene Spunbond Nonwovens, 0.3 Volume% AHCOVEL With surfactant.

Absorbent layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 175 gsm and 0.10 g / cc.

<Example 2>

The layers described below were cut into 4 "x 4" pieces and placed on top of each other in the order described using no adhesive.

Cover Layer: 20.3 gsm (0.6 osy) ESCORENE PD-3445 Polypropylene Spunbond Nonwoven with 3.5 dpf Fiber. Topically applied 0.5% by volume AHCOVEL Treated with surfactant.

Intake / distribution layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 250 gsm, density 0.14 g / cc.

Delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE PD-3445 Polypropylene Spunbond Nonwovens, 0.3 Volume% AHCOVEL With surfactant.

Absorbent layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 175 gsm and 0.10 g / cc.

<Example 3>

The layers described below were cut into 4 "x 4" pieces and placed on top of each other in the order described using no adhesive. A pin puncture process using a pin roller and another (female) roller was used to co-punch only the cover layer and the intake / distribution layer, resulting in a 14% puncture open area with 8 holes / cm 2. The temperature used was 280 ° F (138 ° C) on the pin rolls and 170 ° F (77 ° C) on the arm rolls at a speed of 40 feet / minute.

Cover Layer: 20.3 gsm (0.6 osy) ESCORENE PD-3445 Polypropylene Spunbond Nonwoven with 3.5 dpf Fiber. Topical Applied 0.3% by volume AHCOVEL Treated with surfactant.

Intake / distribution layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 250 gsm, density 0.14 g / cc.

Delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE PD-3445 Polypropylene Spunbond Nonwovens, 0.3 Volume% AHCOVEL With surfactant.

Absorbent layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 175 gsm and 0.10 g / cc.

<Example 4>

The layers described below were cut into 4 "x 4" pieces and placed on top of each other in the order described using no adhesive. Only a cover layer and an intake / distribution layer were co-punched using a pin puncture process using a pin roller and another (female) roller to create a 14% puncture open area with 8 holes / cm 2. The temperature used was 280 ° F. (138 ° C.) on a pin roll and 170 ° F. (77 ° C.) on an arm roll at a speed of 40 feet / minute.

Cover Layer: 20.3 gsm (0.6 osy) ESCORENE PD-3445 Polypropylene Spunbond Nonwoven with 3.5 dpf Fiber. Topically applied 0.5% by volume AHCOVEL Treated with surfactant.

Intake / distribution layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 250 gsm, density 0.14 g / cc.

Delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE PD-3445 Polypropylene Spunbond Nonwovens, 0.3 Volume% AHCOVEL With surfactant.

Absorbent layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 175 gsm and 0.10 g / cc.

Example Intake time (seconds) Rewet (g) One 103 0.11 2 75 0.13 3 50.5 0.12 4 33.5 0.23

As can be seen in Table 1 above, increasing the surfactant content on the nonwoven reduces the intake time of the absorption system. In addition, co-perforating the layers reduces the intake time even further. Combining high surfactant levels with co-perforated layers enhances this effect.

Example 5

The absorber prototypes were assembled with cover adhesives at an add-on level of 2-3 gsm to ensure safety zones as currently marketed in the US market. Kotex with Ultrathin Maxi product was formed.

Cover Layer: 20.3 gsm (0.6 osy) ESCORENE PD-3445 Polypropylene Spunbond Nonwoven, 3.5 dpf. Topical Applied 0.3% by volume AHCOVEL Treated with surfactant. The cover layer was 8 cm x 24.2 cm.

Intake / distribution layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 250 gsm, density 0.14 g / cc. This layer was 10.2 cm x 19 cm.

Delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE PD-3445 Polypropylene Spunbond Nonwovens, 0.3 Volume% AHCOVEL With surfactant. This layer was 5 cm x 20.5 cm.

Absorbent layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 175 gsm and 0.10 g / cc. This layer was 6.4 cm wide x 21.5 cm long.

<Example 6>

These absorbent prototypes were assembled with cover adhesives at an added level of 2-3 gsm to ensure safety zone as currently marketed in the US market. Kotex with Ultrathin Maxi product was formed. Only a cover layer and an intake / distribution layer were co-punched using a pin puncture process using a pin roller and another (female) roller to create a 14% puncture open area with 8 holes / cm 2. The temperature used was 280 ° F. (138 ° C.) on a pin roll and 170 ° F. (77 ° C.) on an arm roll at a speed of 40 feet / minute.

Cover Layer: 20.3 gsm (0.6 osy) ESCORENE PD-3445 Polypropylene Spunbond Nonwoven, 3.5 dpf. Topically applied 0.5% by volume AHCOVEL Treated with surfactant. The cover layer was 8 cm x 24.2 cm.

Intake / distribution layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 250 gsm, density 0.14 g / cc. This layer was 10.2 cm x 19 cm.

Delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE PD-3445 Polypropylene Spunbond Nonwovens, 0.3 Volume% AHCOVEL With surfactant. This layer was 5 cm x 20.5 cm.

Absorbent layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 175 gsm and 0.10 g / cc. This layer was 6.4 cm x 21.5 cm.

The product backing was a layer of 0.6 mils polyethylene film used as fluid restraint device. This layer was attached to the absorbent layer using 20 gsm hot melt adhesive. The backing layer was 8 cm wide x 24.2 cm long.

<Example 7>

The absorbent prototypes were assembled with the cover adhesive at an addition level of 2-3 gsm to SAFETY ZONE as currently marketed in the US market by Kimberly-Clark Corporation. KOTEX with MAXI The product was formed.

Cover Layer: 20.3 gsm (0.6 osy) ESCORENE PD-3445 Polypropylene Spunbond Nonwoven, 3.5 dpf. Topical Applied 0.3% by volume AHCOVEL Treated with surfactant. The cover was 8 cm wide at the target area, 9 cm on the lobes, and 22.0 cm long.

Intake / distribution layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 250 gsm, density 0.14 g / cc. This layer was 9.4 cm x 15.6 cm.

Delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE PD-3445 Polypropylene Spunbond Nonwovens, 0.3 Volume% AHCOVEL With surfactant. This layer was 4.8 cm wide and 20.0 cm long.

Absorbent layer: air formed NB416 pulp fluff, 430 gsm and 0.07 g / cc, 6.0 cm wide at the target area, 7.0 cm on the product lobe and 20.0 cm in length.

Second absorbent layer: air foamed NB416 pulp fluff, 400 gsm, density 0.09 g / cc, width 4.5 cm and length 16.0 cm.

The product backing was a 1.1 mils polyethylene film layer used as a fluid restraint device. This layer was attached to the absorber layer using 40 gsm hot melt adhesive. The backing layer was 8 cm wide in the target area, 9 cm in the lobe, and 22 cm long.

<Example 8>

The absorbent prototypes were assembled with the cover adhesive at an addition level of 2-3 gsm to SAFETY ZONE as currently marketed in the US market by Kimberly-Clark Corporation. KOTEX with MAXI The product was formed.

Only a cover layer and an intake / distribution layer were co-punched using a pin puncture process using a pin roller and another (female) roller to create a 14% puncture open area with 8 holes / cm 2. The temperature used was 280 ° F (138 ° C) on the pin rolls and 170 ° F (77 ° C) on the arm rolls at a speed of 40 feet / minute.

Cover Layer: 20.3 gsm (0.6 osy) ESCORENE PD-3445 Polypropylene Spunbond Nonwoven, 3.5 dpf. Topically applied 0.5% by volume AHCOVEL Treated with surfactant.

Intake / distribution layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 250 gsm, density 0.14 g / cc. This layer was 9.4 cm x 15.6 cm.

Delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE PD-3445 Polypropylene Spunbond Nonwovens, 0.3 Volume% AHCOVEL With surfactant. This layer was 9.4 cm x 15.6 cm.

Absorbent layer: Airformed NB416 pulp fluff, 430 gsm and 0.07 g / cc, 6.0 cm wide at target area, 7.0 cm on product lobe and 20.0 cm long.

Second absorbent layer: air foamed NB416 pulp fluff, 400 gsm, density 0.09 g / cc, width 4.5 cm and length 16.0 cm.

The product backing was a 1.1 mils polyethylene film layer used as a fluid restraint device. This layer was attached to the absorber layer using 40 gsm hot melt adhesive. The backing layer was 8 cm wide in the target area, 9 cm in the lobe, and 22 cm long.

Table 2 shows the test results of the above materials according to the intake and rewet tests shown above.

Example Intake time (seconds) Rewet (g) 5 67.17 0.13 6 33.52 0.16 7 113 0.09 8 41.11 0.09

As can be seen from these results, the co-perforation of the materials showed that the absorption time of the excretion was significantly reduced without adversely affecting the rewet value. By providing a system that will provide a faster intake time, the inventors reduce the run-off of the fluid from the cover, which also reduces the chance of wicking of the fluid through the liner and the user's body causing leakage. It is believed to make.

Co-perforating different product layers allows product developers to control which layers distribute or absorb fluid to what extent. Table 3 presents the fluid distribution test data for Examples 5-8, showing the percentage of fluid retained in each layer. (Examples 6 and 8 were co-punched).

Example Fluid retained in the intake / distribution layer Fluid retained in the first absorbent layer Fluid retained in the second absorbent layer 5 72.14 27.85 N / A 6 47.35 52.64 N / A 7 71.36 23.55 5.08 8 56.20 31.70 12.06

As can be seen from the data in Table 3, the co-perforated system allows for better fluid distribution into the lower absorbent layer, which allows the fluid to stay farther from the cover, giving the wearer a drier surface, To make better use of the total absorbed volume of the product. The amount of fluid in the absorbing layers relative to the intake / distribution can be expressed as a ratio, in this case as the fluid distribution ratio. The fluid distribution ratio for the materials according to the invention should be 70/30 to 20/80, or more preferably 60/40 to 20/80.

Clearly, the choice of raw material and the choice of layers to be co-perforated determine how well the product will perform. One area where the present invention benefits is in systems with higher density absorbers closer to the cover. Such systems tend to provide elasticity to the product in order to reduce agglomeration or warping during use, and to preferentially distribute the fluid in the X-Y plane. This allows for more effective absorption of multiple excretion.

One skilled in the art can readily design products with different material densities and absorbents that benefit from the co-perforation of selected layers that allow for faster absorption and fluid retention in the desired area of the product. The aperture arrangement can be designed for different layers to improve fluid movement through the product.

Another example of a cover co-perforated with an intake layer can be seen in the following examples:

Example 9

Cover layer: 20.3 gsm (0.6 osy) polypropylene spunbond nonwoven, 3.5 dpf. Topical 0.3 volume% AHCOVEL Treated with surfactant.

Intake / distribution layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 175 gsm, density 0.14 g / cc. This layer was 19.0 cm wide and 37 cm long.

Delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE PD-3445 Polypropylene Spunbond Nonwovens, 0.3 Volume% AHCOVEL With surfactant. This layer was 20.6 cm long and 4.8 cm wide.

Absorbent layer: Airform NB416 pulp fluff, 500 gsm, 0.09 g / cc, length 20.6 cm and width 4.8 cm. The lower fluff has a basis weight of 600 gsm, a density of 0.09 g / cc, a length of 29.5 cm, a width of 6.5 cm at the center and 7.5 cm at the lobe.

The product backing was a 1.1 mils polyethylene film layer used as a fluid restraint device. This layer was attached to the absorber layer using 40 gsm hot melt adhesive. The backing layer was 8.5 cm wide in the target area, 9.5 cm in the lobe, and 31.5 cm long.

<Example 10>

Only a cover layer and an intake / distribution layer were co-punched using a pin puncture process using a pin roller and another (female) roller to create a 14% puncture open area with 8 holes / cm 2. The temperature used was 280 ° F (138 ° C) on the pin rolls and 170 ° F (77 ° C) on the arm rolls at a speed of 40 feet / minute.

Cover layer: 20.3 gsm (0.6 osy) polypropylene spunbond nonwoven, 3.5 dpf. Topical Applied 0.3% by volume AHCOVEL Treated with surfactant.

Intake / distribution layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 175 gsm, density 0.14 g / cc. This layer was 19.0 cm wide and 37 cm long.

Delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE PD-3445 Polypropylene Spunbond Nonwovens, 0.3 Volume% AHCOVEL With surfactant. This layer was 20.6 cm long and 4.8 cm wide.

Absorbent layer: Airformed NB416 pulp fluff, 500 gsm, 0.09 g / cc, 20.6 cm in length and 4.8 cm in width, lower fluff layer having a basis weight of 600 gsm, density of 0.09 g / cc, length of 29.5 cm , 6.5 cm wide at the center and 7.5 cm on the lobe.

The product backing was a 1.1 mils polyethylene film layer used as a fluid restraint device. This layer was attached to the absorber layer using 40 gsm hot melt adhesive. The backing layer was 8.5 cm wide in the target area, 9.5 cm in the lobe, and 31.5 cm long.

<Example 11>

Only a cover layer and an intake / distribution layer were co-punched using a pin puncture process using a pin roller and another (female) roller to create a 14% puncture open area with 8 holes / cm 2. The temperature used was 280 ° F (138 ° C) on the pin rolls and 170 ° F (77 ° C) on the arm rolls at a speed of 40 feet / minute.

Cover Layer: 20.3 gsm (0.6 osy) ESCORENE PD-3445 Polypropylene Spunbond Nonwoven, 3.5 dpf. Topical Applied 0.3% by volume AHCOVEL Treated with surfactant.

Surge layer: 23.7 gsm (0.7 osy) 6 dpf ESCORENE PD-3445 Polypropylene Spunbond Nonwoven Polypropylene Fiber Web, with HR6 Finish. Fiber with a finish available from Chisso Corp. This layer was 19.0 cm wide, 37 cm long and 1.3 mm thick.

Intake / distribution layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 175 gsm, density 0.14 g / cc. This layer was 19.0 cm wide and 37 cm long.

Delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE PD-3445 Polypropylene Spunbond Nonwovens, 0.3 Volume% AHCOVEL With surfactant. This layer was 20.6 cm long and 4.8 cm wide.

Absorbent layer: Airformed NB416 pulp fluff, 500 gsm, 0.09 g / cc, length 20.6 cm and width 4.8 cm, the lower fluff layer has a basis weight of 600 gsm, 0.09 g / cc, length 29.5 cm and at center Width is 6.5 cm and 7.5 cm on the lobe.

The product backing was a 1.1 mils polyethylene film layer used as a fluid restraint device. This layer was attached to the absorber layer using 40 gsm hot melt adhesive. The backing layer was 8.5 cm wide in the target area, 9.5 cm in the lobe, and 31.5 cm long.

<Example 12>

A pin punching process using a pin roller and another (female) roller was used to co-perforate the intake / distribution layer and the transfer retardation layer to produce a 14% puncture open area with 8 holes / cm 2. The temperature used was 280 ° F (138 ° C) on the pin rolls and 170 ° F (77 ° C) on the arm rolls at a speed of 50 feet / minute.

Cover layer: vacuum perforated polyethylene film, 17% open area, 100 holes / cm 2, 19 gsm.

Intake / distribution layer: 90 wt% NB416 pulp and 10 wt% KoSa T-255 binder fibers, 175 gsm, density 0.14 g / cc. This layer was 19.0 cm wide and 37 cm long.

Delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE PD-3445 Polypropylene Spunbond Nonwovens, 0.3 Volume% AHCOVEL With surfactant. This layer was 20.6 cm long and 4.8 cm wide.

Absorbent layer: Airformed NB416 pulp fluff, 500 gsm, 0.09 g / cc, length 20.6 cm and width 4.8 cm, the lower fluff layer has a basis weight of 600 gsm, density of 0.09 g / cc, length 29.5 cm, Width 6.5 cm in the target area and 7.5 cm on the lobe.

The product backing was a 1.1 mils polyethylene film layer used as a fluid restraint device. This layer was attached to the absorber layer using 40 gsm hot melt adhesive. The backing layer was 8.5 cm wide in the target area, 9.5 cm in the lobe, and 31.5 cm long.

The examples were tested according to the triple intake test and the rewet test described above and the results are shown in Table 4.

Example Intake time of the first excretion in seconds Intake time of second excretion in seconds Intake time of the third excretion in seconds Rewet (g) 9 43 58 132 0.45 10 41 49 98 0.19 11 8 13 23 0.15 12 12 17 24 0.03

As can be seen in these examples, co-perforating the cover with different absorbent layers in multiple excretion situations has shown an advantage in reducing material intake time. In Example 10, the available open area can be further optimized and processed, for example, to further reduce the intake time of the system. It can also be seen from the data that the larger empty volume material in the cover generally has a faster intake time for multiple excretion and shows a significant reduction compared to the non-perforated absorption system.

As will be appreciated by those skilled in the art, changes and variations to the present invention are contemplated as being within the skill of those skilled in the art. Such changes and variations are intended to be within the scope of the present invention by the inventors.

Claims (20)

A cover layer adjacent the intake / distribution layer, the intake / distribution layer adjacent the absorbent core on the opposite side of the cover layer, and the cover layer and the intake / distribution layer are co-perforated (co-). apertured) system for hygiene products. The system of claim 1, further comprising a delivery retardation layer between the intake / distribution layer and the absorbent core. The system of claim 1 wherein the open area of 2 to 25% and the perforation area is less than 19.6 mm 2. The system of claim 3, wherein the third excretion intake time is less than 35 seconds. The system of claim 3 wherein the re-wet value is less than 0.3 g. The system of claim 1 wherein the basis weight of the intake / distribution layer is between 50 and 500 gsm. The system of claim 1, wherein the cover material is treated with a wettable surfactant. The system of claim 1, wherein the cover material is treated with a skin health additive. The system of claim 1 wherein the cover material is an embossed nonwoven fabric. The system of claim 1 wherein the fluid distribution ratio of the system is between 60/40 and 20/80. And a non-woven cover layer, an intake / distribution layer, and an absorbent layer, wherein the cover layer and the intake / distribution layer are co-perforated. 12. The pad of claim 11 further comprising a propagation delay layer adjacent said absorbent core. The pad of claim 12, wherein the delivery retardation layer is a material selected from the group consisting of spunbond fabrics, meltblown fabrics, carded fabrics, and films. 12. The pad of claim 11 wherein the delivery retardation layer is a spunbond fabric having a basis weight of about 15 to 50 gsm. The group of claim 11, wherein the intake / distribution layer is comprised of airlaid fabric, bonded carded web, coform material, hydroentangled pulp fabric, and meltblown fabric. The pad is a material selected from. 12. The pad of claim 11 wherein the intake / distribution layer is an airlaid fabric having a basis weight of about 100 to 300 gsm and a density of about 0.06 to 0.18 g / cc. The pad of claim 11, wherein the cover layer, intake / distribution layer, and delivery retardation layer are co-perforated at a density of about 1 to 15 perforations / cm 2. 12. The pad of claim 11 further comprising a surge layer between the cover layer and the intake / distribution layer. 19. The pad of claim 18, wherein said cover layer, surge layer, and intake / distribution layer are co-perforated at a density of about 1 to 15 perforations / cm &lt; 2 &gt;. Polypropylene fiber nonwoven cover layer, pulp and binder fiber intake / distribution layer with density of about 0.09 to 0.19 g / cc and basis weight of about 100 to 300 gsm, nonwoven delivery delay layer, density of about 0.05 to 0.10 g / a first absorbent layer comprising a pulp fluff having a cc and a basis weight of 150 to 500 gsm, and a second absorbent layer having a density less than the first absorbent layer and comprising pulp fluff, wherein the layers are from 1 to 1 Feminine hygiene pad, co-drilled at a density of 15 punctures / cm 2.