US20110011549A1

US20110011549A1 - Processes for molding pulp paper containers and lids

Info

Publication number: US20110011549A1
Application number: US12/821,054
Authority: US
Inventors: David Pierce; Edward Urquhart
Original assignee: Seanet Dev Inc
Current assignee: SEANET DEVELOPMENT Inc; Seanet Dev Inc
Priority date: 2009-04-27
Filing date: 2010-06-22
Publication date: 2011-01-20

Abstract

A process for molding recyclable, compostable, and disposable containers made of pulp paper is disclosed herein. The process includes disposing a wet pulp layer on a male or female mold, mating the mold with its counterpart, and applying a force on the pulp layer to remove moisture and thin the pulp. The process continues by applying a vacuum to either the male or female mold to hold the pulp layer, and removing the other mold. The process further comprises sequentially mating male and female molds until the pulp layer is the desired thickness and shape of the container. Embodiments of the process may include molding pulp containers to include pleats, stability features, reverse draft features, and puffed pulp configurations.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part patent application that claims the benefit of and priority to: U.S. patent application Ser. No. 12/767,765, titled PROCESSES FOR MOLDING PULP PAPER CONTAINERS AND LIDS, filed Apr. 26, 2010, which claims the benefit of and priority to U.S. Provisional Patent Application No. 61/172,965, titled MOLDED PULP PAPER CONTAINER FOR LIQUIDS AND BEVERAGES, filed Apr. 24, 2009; U.S. Provisional Patent Application No. 61/219,712, titled CREATING AND RUNNING A REVERSE DRAFT ON PAPER PULP MOLDING MACHINERY AND SUBSEQUENT POSSIBILITIES FOR FORMING UNIQUE SHAPES AND PROFILES, filed Jun. 23, 2009; and U.S. Provisional Patent Application No. 61/301,934, titled MOLDED PAPER CUP CONTAINER FOR LIQUIDS AND BEVERAGES, filed Feb. 5, 2010; each of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to containers made of paper, and more specifically to molding pulp or forming paper to form paper containers. The present invention also relates to containers for disks, and is more particularly concerned with a disk storage tray for storage of a disk.

BACKGROUND

Paper tubs, containers, and cups are made out of pulp, which is inherently fragile when wet, and, accordingly, the standard methods of manufacturing paper containers begin with dry sheets of finished paper. Using a paper cup as an example, paper sheets are first die cut into specific shapes and then wound onto a mandrel. A cylindrical shape is formed, and the pulp paper cup is then glued or sealed at a seam. Next, a base of the cup is die cut and glued or sealed at a base seam adjacent to the cylindrical portion of the cup. Most paper cups and other paper containers have a top edge portion that requires an additional manufacturing step, e.g., creating a lip roll, which provides the container with circumferential strength. In addition, since paper is water permeable, the paper used in containers must be pre-printed and laminated with a water resistant layer, either before or after manufacturing, to ensure the containers are capable of holding food and beverages. Furthermore, paper containers, especially cups, made with this standard manufacturing method often necessitate the use of thermal insulating sleeves to prevent a user from being burned by the hot contents of the container. Manufacturing thermal insulating sleeves requires an additional manufacturing step and additional machining tools. Therefore, the standard method of manufacturing paper containers requires numerous processes and numerous machine tools.
Molding plastic is a less complex method of manufacturing containers. The elasticity of plastic simplifies manufacturing to the following steps: pouring heated plastic into a mold having a desired container shape, allowing the plastic to harden, and removing the hardened plastic from the mold. More complex shapes may also be made during thermo forming of plastics since the elasticity of plastic allows it to bend in different directions and resiliently recover when drawn from a mold. Unfortunately, molding techniques used for plastic containers are generally incompatible with pulp paper because wet pulp is inelastic and fragile. Applying standard molding techniques causes the pulp to tear. Additionally, pulp molding is less capable of attaining complex shapes, e.g., reverse drafts on surfaces, since it cannot elastically recover when drawn from molds. Therefore, it is desirable to have a less complex method for manufacturing paper containers that accommodates the material characteristics of pulp.
Disk storage trays for storage and packaging of disks having a generally centrally situated circular aperture, for example compact disks (CD), digital video disks (DVD), High Definition digital video disks (HD-DVD), and Blu Ray® disks (BD) are well known in the art. Typically, such trays are constructed of injection formed plastic, thermoformed plastic, or molded cellulose pulp, for example molded paper or cardboard. Unfortunately, the use of petrochemical based molded or thermoformed materials, e.g. plastics, for the trays is undesirable due to the negative impact of such materials on the environment. Cellulose or paper materials offer environmentally friendly and sustainable options for making such trays, compared to plastics. However, such cellulose pulp materials generally offer inferior results for disk packaging trays, at least compared to plastics. In particular, trays made from cellulose pulp-based materials typically fail to retain the disk on the tray, via central posts or the like which insert through the aperture, compared to plastic trays. Thus, the disk is often not well retained in the tray for cellulose-based pulp trays, compared to plastic-based trays, increasing the risk that the disk may fall out of the tray during storage and/or transport and be damaged.
Accordingly, there is a need for an improved disk storage tray.

SUMMARY

The present disclosure is directed to a process for molding a pulp container that overcomes problems experienced in the prior art. The present disclosure is further directed to a method of molding a container that is made of recyclable, disposable, and/or compostable cellulose fiber materials. A generally accepted definition of compostable is a material that is able to break down into carbon dioxide, water and biomass at the same rate as paper. Compostable material also does not produce toxic material and is generally able to support plant life.
A container made in accordance with at least one embodiment of the present disclosure may be made from renewable resources that may include recycled materials, biodegradable materials, compostable materials, and organics, e.g., cellulose fiber, tapioca, wood, agricultural recycled crop materials, and plastics, e.g., PLA. The container may also be made from materials including non-organics, e.g., clay, metals, and petro plastics, e.g., silicone, PVC's, and PET styrene. An embodiment in accordance with the present disclosure includes molding a container made of pulp.
Embodiments of the present disclosure include processes for forming molded pulp containers, such as cups and/or lids. Some embodiments may include using molds having greater draft angles than typical molding to accommodate for the fragility of wet pulp. The processes disclosed herein may also result in greater insulation because the resulting pulp container has a less densely formed substrate due to the forming and pressing processes associated with embodiments of the invention. Molded containers manufactured with this process can include a variety of homogeneous and non-homogeneous shapes.
Embodiments in accordance with the present disclosure provide a process for molding containers that include a pleat. Pleats are advantageous since they allow containers to be molded with larger draft angles for easy removal from molds. The pleats are subsequently folded, thereby forming a seam and a container having a smaller draft angle, a smaller diameter, and a greater height than the mold.
Another embodiment of the present disclosure is drawn to processes that include containers having specially shaped edges. For example, cups may include a top edge having a contoured lip or roll. This forms a more desirable drinking surface and makes it easier to connect the cup to a lid.
Still other embodiments in accordance with the present disclosure provide a process for molding a container including a reverse draft feature. For example, lids include reverse draft features to securely connect to containers. Containers themselves also have reverse draft features. Embodiments in accordance with this process include first molding pulp along a horizontal axis to include pleat configurations, gradually bending the pulp to a reverse draft angle using sequential molds, removing the molds, and collapsing the pleats on the pulp to form the reverse draft feature.
It is therefore a general object of the present invention to provide an improved disk storage tray.
An advantage of the present invention is that the disk storage tray is made of pulp cellulose material, such as molded paper or cardboard, that is relatively environmentally friendly compared to plastics.
Another advantage of the present invention is that the disk storage tray is easy to manufacture.
Still another advantage of the present invention is the disk storage tray firmly holds the disk in the tray.
Yet another advantage of the present invention is that the disk may be easily removed and replaced in the tray.
In one aspect, the present invention provides a disk storage tray for a disk having a circular aperture formed therein and defined by an inner disk edge disposed generally centrally on the disk, the tray comprising:

- generally adjacent and planar first and second tray portions, the tray portions together defining a top side and a bottom side of the tray;
- a connector pivotally connecting the first and second tray portions and upon which the tray portions are pivotal between an extended configuration for the tray, in which the tray portions extend substantially colinearly one another, and a retracted configuration for the tray, in which the tray portions are slanted towards one another on the top side;
- first and second generally opposed central portions extending, respectively, across the first and second tray portions adjacent the connector, each central portion being indented inwardly relative the bottom side; and
- first and second generally opposed posts protruding, respectively, upwardly from the top side adjacent the connector and flaring angularly outwardly relative the connector, the posts being spaced apart from one another at outer top edges thereof at a lesser distance than the diameter of the aperture in the retracted configuration, thereby enabling insertion and removal of the disk by passage of the posts through the aperture, and a greater distance than the diameter of the aperture in the extended configuration, thereby preventing passage of the posts through the aperture and enabling retaining of the disk on the tray.

Other objects and advantages of the present invention will become apparent from a careful reading of the detailed description provided herein, with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, the sizes and relative positions of the elements in the drawings are not necessarily drawn to scale. For example, the shapes of the various elements and angles are not drawn to scale, and some of these elements are arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn are not intended to convey any information regarding the actual shape of the particular elements, and have been solely selected for ease of recognition in the drawings. Understanding that these drawings depict only one embodiment of the disclosure and are not therefore to be considered as limiting of its scope, the disclosure will be described and explained with additional specificity and detail through the use of the accompanying drawings.

FIGS. 1A-H are schematic cross-sectional views illustrating a number of stages of a process for molding a pulp paper cup in accordance with an embodiment of the invention.

FIGS. 2A and 2B are schematic cross sectional views of a pulp layer between male and female molds of an alternate embodiment.

FIGS. 3A-3C are schematic cross-sectional views of a pulp layer between male and female molds of another alternate embodiment.

FIGS. 4A and 4B are schematic cross-sectional views of a pulp layer between male and female molds of another alternate embodiment.

FIG. 5A is a perspective view of a molded pulp paper cup having a pleat in accordance with an embodiment of the invention.

FIG. 5B is a top view of a molded pulp paper cup having a pleat in accordance with an embodiment of the invention.

FIG. 6 is a front view of a molded pulp paper cup having an angular base in accordance with an embodiment of the invention.

FIG. 7 is a perspective view of a molded pulp paper cup having fins in accordance with an embodiment of the invention.

FIGS. 8A-F are schematic cross-sectional views illustrating a number of stages of a process for molding an upper edge of a pulp paper cup in accordance with an embodiment of the invention.

FIGS. 9A-F are cross-sectional and perspective views illustrating a number of stages of a process for molding a reverse draft feature on a pulp paper lid in accordance with an embodiment of the invention

FIGS. 10A-D are schematic cross-sectional views illustrating a number of stages of a process for molding a puffed pulp construction in accordance with an embodiment of the invention.

FIG. 11 is a cross-sectional view of a molded pulp paper cup and lid assembly having a reverse draft feature with a puffed pulp construction in accordance with an embodiment of the invention.

FIG. 12 is a top perspective view of an embodiment of a disk storage tray in accordance with the present invention.

FIG. 13 is a bottom perspective view of the disk storage tray shown in FIG. 12.

FIG. 14 is a side elevational view of the disk storage tray shown in FIG. 12 demonstrating a retracted configuration therefore.

FIG. 15 is a side elevational view of the disk storage tray shown in FIG. 12 demonstrating an extended configuration therefor.

FIGS. 16A-16E are isometric and side elevation views of a disk storage tray in accordance with an embodiment of the present invention.

Appendix A includes prospective views of other molded pulp paper containers in accordance with embodiments of the invention.
From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.

DETAILED DESCRIPTION

The following describes embodiments of a process for molding a pulp container in accordance with the present disclosure. Embodiments in accordance with the present disclosure are set forth hereinafter to provide a thorough understanding and enabling description of a number of particular embodiments. Several specific details of the disclosure are set forth in the following description and in FIGS. 1-7 to provide a thorough understanding of certain embodiments of the disclosure. For example, FIGS. 1-7 illustrate a pulp container as a cup and/or a lid. However, it should be noted that the process described below can be used to make any suitable container or insulating sleeve made of pulp paper. A cup and lid are only one embodiment of a molded pulp container made by the disclosed process. Appendix A illustrates other suitable shapes in accordance with the invention. One skilled in the art, however, will understand that the present disclosure may have additional embodiments, and that other embodiments of the disclosure may be practiced without several of the specific features described below.
Embodiments of processes in accordance with the present disclosure may include molds having tapered surfaces that form a draft angle between the mold and the parting line of the molded material. Draft angles allow for easy removal of the formed container for the mold. For example, FIG. 1A illustrates a pulp layer 1 positioned between a male mold 2 and a female mold 3. The pulp layer is held against the male mold 2 using a vacuum and the female mold 3 is removed. The angle θ is the draft angle between pulp layer 1 and male mold 2 that simplifies removal of the female mold 3. Features that are not positioned in the same direction as the mold is removed, i.e., the draw of the mold, are said to have reverse draft or be positioned on a negative draft angle.
FIGS. 1B-1H illustrate sequential stages of an embodiment of a process for forming a molded pulp cup in accordance with the disclosure. FIG. 1B, more specifically, is a cross-sectional view at the initial stage of the process in which a wet, pulp layer 101 is held against the exterior surface of a male forming mold 102. The pulp layer 101 is formed on the male forming mold 102 using any suitable method, e.g., positioning the male forming mold 102 in a slurry of wet pulp and drawing a vacuum (i.e., a negative pressure) through the mold surface to draw the pulp onto the mold until a sufficient amount of pulp covers the mold.
FIG. 1C illustrates a subsequent stage of the process that includes axially mating a first female mold 103 with the layer of pulp on the male forming mold 102, thereby sandwiching the pulp layer 101 between the female and male molds. During this first molding process, the layer of wet pulp is substantially compressed, thereby squeezing or otherwise removing a substantial amount of water out of the pulp layer. The distance between the two molds is known as an offset 110. The offset of the initial mold set in one embodiment is approximately 3 mm-5 mm and becomes sequentially smaller as the molding process continues in subsequent molds, so as to incrementally compress and thin the pulp without tearing. The male forming mold 102 and the first female mold 102 have a cross-section shape including a lower portion with a first draft angle and a splayed upper portion with a second draft angle greater than the first draft angle. This general shape, optionally including a large draft angle, helps to insure that the layer of fragile wet pulp does not tear during insertion or removal from a mold.
In the subsequent stage of the process illustrated in FIG. 1D, the male forming mold 102 is removed from the first female mold 103. The pulp layer 101 is held to the interior surface of the first female mold 103 by applying a vacuum to the first female mold, between the mold surface and the pulp. Additionally, pressurized air may be forced through the male forming mold 102 to assist in removal and work in conjunction with the vacuum to hold the pulp layer 101 against the first female mold 103.
In another embodiment in accordance with the present disclosure, the pulp layer 101 is formed directly on the first female mold 103 using with a process similar to the process discussed above. For example, the wet pulp can be initially coated or otherwise disposed on the interior surface of the female mold 103 and a vacuum can be drawn through the mold surface to hold the layer of pulp 101 against the first female mold 103. In this embodiment, the process begins at FIG. 1D. It is noted for the reader that the draft angle at the upper portion of the first female mold 103 is shown in an exaggerated manner to visually illustrate the difference in the draft angle of the upper portion relative to the lower portion of the female mold and to the draft angle of the male mold. In at least one embodiment, the draft angle of the lower portion of the female mold and the male mold is approximately 1°-7°, and the offset therebetween is approximately 0.01 mm-5 mm. The draft angle of the upper portion of the female mold is approximately 2°-14°, and the offset increases to approximately 4 mm-6 mm, depending upon the depth of mold draw. In one embodiment provided as an example, the draft of the lower portion of the molds is approximately 5°, and the draft of the upper portion of the molds is approximately 8°. Other embodiments can use other mold configurations.
FIG. 1E illustrates the subsequent stage of the process for molding a cup that includes mating a first male mold 104 with the first female mold 103. In this step illustrated in FIG. 1E, the molds 103 and 104 apply a force on the pulp layer 101 due to the wedging of the male mold against the female mold to provide compression from the molds against the pulp layer 101. The compressive force squeezes excess moisture (e.g., water) from the pulp, causing the pulp layer 101 to thin. In FIG. 1E, the offset upper portion of the first female mold 103 may be smaller at the lower region than the upper region.
The subsequent stages of the process are shown in FIGS. 1F and 1G, in which a vacuum is applied through the first male mold 104, thereby drawing the pulp layer 101 away from the first female mold 103 and holding the pulp layer 101 against male mold 104. Additionally, pressurized air may be applied to the first female mold 103 in accordance with the direction of the arrows in FIG. 1G. The additional pressurized airflow acts in conjunction with the vacuum to smoothly remove the pulp off the female mold 103 and firmly hold the pulp layer 101 against the male mold 103. Once the pulp layer is held against the surface of the male mold 104 as illustrated in FIG. 1G, the first female mold 103 is removed and moved away from male mold 104 and the pulp layer 101. As described above, the upper portion of the first female mold 103 may have a larger draft angle than subsequent female molds so as not to tear the pulp layer 101 while it is most fragile during the initial molding steps of the process.
In accordance with the subsequent stage of the process shown in FIG. 1H, a second female mold 105 mates with the male mold 104 that carries the pulp layer 101 thereon. This combination of the second female mold 105 and the first male mold 104 has a smaller offset than first female mold 103 in combination with the male mold 104. Upon pressing the male mold 104 and the pulp layer into the second female mold 105, wedging and compressive forces are applied to pulp layer 101 to squeeze out additional moisture and to further thin the pulp layer 101. Additionally, the second female mold 105 can be configured to provide an offset relative to the male mold 104 that is smaller at the upper region of the molds 104 and 105 than the offset between the lower region of the molds 104 and 105. This variation in the offset between the mating molds results in the molds exerting more force on the upper portion of pulp layer 101 than on the lower portion during this stage of the molding process. One of the benefits of this varied offset is that it minimized the risk of damage to the pulp layer when separating the male and female molds. It also provides a varied wedging forces to different portions of the pulp layer during different sequential molding steps.
In the next step of the process, the second female mold 105 is removed from the pulp layer 101, which remains on the male mold. This process is similar to that described above with reference to FIGS. 1F and 1G wherein a vacuum is drawn through the male mold 104, and, optionally, pressurized air is applied inwardly from the second female mold 105 so that pulp layer 101 is held against male mold 104 and the second female mold can be easily and safely removed without damaging the pulp layer 101.
In accordance with embodiments of the disclosure, the process includes mating additional female molds with the pulp layer on the male mold 104 until the pulp layer 101 is the desired shape and thickness of the cup. The process of mating an additional female mold is similar to the sequence of stages described above with reference to FIGS. 1E-H. Each subsequent female mold has a decreased offset relative to the male mold to apply compressive forces to the pulp layer 101 to squeeze out additional moisture and to sequentially thin the pulp layer 101 until a desired thickness of the pulp layer is achieved. The offsets created by each subsequent female molds may also vary within individual female molds in a manner that is essentially opposite from the previous female mold. For example, the offset between the female and male molds discussed above included a slightly greater offset at the lower region of the molds than at the upper regions of the mold. This provides greater compression and thinning of the upper portion of the pulp layer during this step of the molding process.
The next female mold can be configured so that, when combined with the male mold, the molds will have an offset A at the lower portion of the mold that is slightly less than the an offset B at the upper portion molds. This provides greater compression and thinning of the lower portion of the pulp layer during this step of the molding process. The subsequent female molds, when combined with the male mold, may have alternating variations of the offsets A′ and B′ at the lower and upper portions of the mold, respectively Varying the offsets within individual molds and alternating the position of the varied offset of subsequent molds decreases the defects on the completed pulp paper container since the pulp is not continuously compressed against the same portions of the male mold. In the illustrated embodiment, the final pair of female and male molds will have a selected offset, uniform or varied, that provides the desired thickness of the pulp layer for the final product. For example, if the final product is designed to have a uniform thickness, the offset between the final set of female and male molds will have a uniform offset.
FIGS. 2A and 2B illustrate an alternate embodiment wherein the pulp layer 101 is retained female mold 203, and the male mold 204 is inserted into the female mold 203 to compress and thin the pulp layer. The male mold is configured with different draft angles relative such that the offset between the lower portion 206 of the female and male molds 203 and 204 is greater than the offset between the upper portion 208 of the female and male molds.
In accordance with embodiments of the present disclosure, the process may also include a varying number of molding steps for molding the pulp layer between selected sequential sets of male and female molds depending upon the desired thickness and shape of the container. For example, one embodiment forms the molded pulp product using three molding steps with three sets of sequential pairs of molds, each having increasingly smaller offsets. Other embodiments can includes five to seven sequential molding steps with the selected pairs of male and female molds. Additional embodiments in accordance the present disclosure may include more or less repetitions. In some embodiments, the use of a greater number of molding steps can provide for better throughput in the molding process to provide a greater number of molded pulp products in a selected time period.
The molding process described above with reference to FIGS. 1E-H includes sequential mating of multiple female molds with one male mold 104 (which that retains the pulp layer on it throughout the molding process. In an alternate embodiment, the molding process can include sequential mating of multiple male molds with one female mold that retains the pulp layer therein throughout the molding process. For example, this embodiment of the process included holding a pulp layer against a female mold having the desired exterior diameter of the container with a vacuum. A first male mold is then mated with the female mold, applying a wedging and compressive force on the pulp layer, thereby removing excess moisture from the pulp and thinning the pulp layer. Next, a vacuum is drawn the female mold to hold the pulp layer against the female mold. Additionally, pressurized air may be blown radially from the first male mold to act in conjunction with the vacuum, holding the pulp layer on the female mold and helping remove the first male mold. In the next step of the process, a second male mold is mated with the female mold, wherein this second set of molds has a smaller offset compared to the offset of the first pair of molds. The reduced offset removes additional moisture and further thins the pulp layer.
In accordance with this embodiment of the process, each subsequent male mold has a greater diameter than the previous male mold so as to decrease the offset between the molds, and the number of male molds may vary depending upon the desired thickness and shape of the resulting molded pulp product. Additionally, as described above with reference to female molds, the male molds can be configured to provide varied offsets between different portions of a set of male and female molds, i.e., the lower portion compared to the upper portion of the mold. The positions of the varied offset may alternate between subsequent male molds.
Still further embodiments in accordance with the present disclosure can include alternating the vacuumed surface between male and female molds so that the pulp layer 101 is retained on a male mold at one molding station and then on the female mold at the next molding station. For example, as illustrated in FIGS. 3A-3C, a layer of pulp 101 may first be held against a first female mold 303, and a first male mold 304 may be mated with the first female mold, exerting a compressive force on the pulp layer to remove excess moisture and thin the pulp layer. The illustrated first male mold 304 has variable draft angles. A vacuum is then drawn through the first male mold 304 to hold the pulp layer against it and pressurized air may be forced through the first female mold 303 to work in conjunction with the vacuum, holding the layer of pulp against the first male mold and aiding in the removal of the first female mold. A second female mold 306 (FIG. 3B) is then mated with the first male mold 304, decreasing the offset and exerting a compressive force on the pulp layer 101 to remove excess moisture and further thin the pulp. Next, a vacuum is drawn through the second female mold 306, thereby holding the pulp layer 101 against it, and the first male mold 304 is removed. A second male mold 308 is then mated with the second female mold 306. This process may be repeated until the pulp layer is the desired thickness and shape. With each repetition, the offset is decreased. Additionally, in some embodiments the offset may be varied within the molds and alternated as described above. Switching the mold on which the pulp layer is held allows the pulp to “paddy-cake” between the male and female molds, and further decreases any defects transferred to the inner and outer surfaces of the pulp layer since the pulp layer is not retained on the same male or female mold during the molding process. In an additional embodiment, the pulp may first be vacuumed to the female mold, subsequently vacuumed onto the male mold, and continue with the “paddy-cake” sequence described above.
FIGS. 4A and 4B are schematic cross-sectional views of an alternate embodiment having male and female molds used to mold a pulp layer 101 into a selected molded pulp product. In the illustrated embodiment, the female mold 403 is similar to the female molds discussed above. The male mold 404 is a multi-segmented partially conical shaped mold assembly that includes a plurality of shaped mold segments 406. In the illustrated embodiment the mold segments 406 are carried by a central shaft 408. The mold segments 406 are axially moveable on the central shaft 408 so the segments can be spaced apart from each other to form an initial molding position as shown in FIG. 4A. The mold segments can be moved relative the shaft to a final mold position wherein the mold segments are stacked upon each other. Accordingly, the draft angle of the male mold when in the initial position is less than the draft angle of the male mold when in the final mold position.
In operation of one embodiment, the pulp layer 101 is carried by the female mold 403 as discussed above. The male mold 404 is in the initial molding position with the mold segments 406 spaced apart before the male mold is inserted into the female mold. When the male mold 404 is axially inserted into the female mold 403 to compress the pulp layer, the first (bottom mold) segment 410 pressed into the bottom portion of the pulp layer to compress the pulp layer against the female mold. In this position, when the mold segments are still in the initial position, which defined the first drat angle, the mold segments provide some compressive forces against the pulp layer. The remaining mold segments 412-420 are then moved axially along the central shaft until the segments are stacked upon each other and in the final mold position. As the mold segments are moving to the final mold position, the effective draft angle of the male mold increases and the segments provide increased wedging and compression forces against the pulp layer that drives moisture from the pulp layer 101 and further thins the pulp layer. In one embodiment, the mold segments 412-420 can all be substantially simultaneously moved into the final mold position. In another embodiment, the mold segments can be moved sequentially into to their respective final mold positions. Although the illustrated embodiment shows male and female molds with a cup shape, other embodiments can provide molds for forming molded pulp containers with other shapes.
As shown in FIGS. 5A and 5B, additional embodiments in accordance with the present disclosure include processes for forming a pulp cup 500 having a pleat 501. Pulp is molded in accordance with any of the processes described above, except the male and female molds each have an indentation configured to form a pleat similar to pleat 501 on cup 500. After the molding process is completed, the molded product has the pleat in an expanded, unfolded position. The pleat can then be folded to a collapsed position so as to decrease the diameter and the draft angle of the molded product. The folded pleat will appear to be a vertical seam on the sidewall of the molded pulp cup. Embodiments in accordance with the present disclosure may include more than one pleat positioned around the circumference of the cup or other container. Molds including an indentation configured to form a pleat have the advantage of permitting the use of a greater draft angle, thereby decreasing the difficulty of removing the fragile pulp layers from the molds, especially during the initial molding steps. This results in a reduced risk of tears or defects within the pulp layer during the molding process.
Additional embodiments in accordance with the present disclosure include processes for molding pulp products having non-cylindrical features. For example, FIGS. 6 and 7 illustrate different shapes or features that may be included in the pulp molding processes disclosed above. FIG. 6 illustrates a cup 600 that has an angular sections 601 on the lower portion of the cup that provide stability and greater surface area through which heat may dissipate. Additionally, the shape of cup 600 permits the use of greater draft angles for easier removal of pulp from the molds. In further embodiments of containers made in accordance with the process of the present disclosure, FIG. 7 illustrates a cup 700 that has fins 701 protruding from the base of the cup 702. These fins 701 provide greater stability. The pulp molding process used to form cup 600 and cup 700 may include any of the molding processes described above, except that the male and female molds include the desired features of the cups 600 and 700. It should be noted that non-cylindrical cup features are not limited to the structures shown in FIGS. 6 and 7. These are merely an illustration of some features that may be included in pulp molding.
Each of the above embodiments may further include a process for forming an upper edge feature on a container. FIGS. 8A-F illustrate stages of an embodiment of a process for forming an edge on a molded pulp cup in accordance with the disclosure. More specifically, FIG. 8A is a cross-sectional view at the initial stage of forming an edge wherein a pulp layer 101 is held against a first female mold 803, the pulp layer 101 extending beyond the first female mold 803. In the subsequent stage of the process illustrated in FIG. 8B, a first male mold 802 is mated with the female mold 803. The first male mold 802 has an upper portion 802 a that pushes vertically down on the portion pulp layer 101 extending beyond the first female mold 803 and causes the pulp layer 801 to bend outwardly over edge of the first female mold 803.
FIGS. 8C and 8E illustrate the next sequential steps in the process in accordance with the disclosure. As described above, a vacuum is applied to the first male mold 802 and pressurized air may be blown radially inward from the first female mold 803 to hold the pulp layer on the first male mold 802 and remove the first female mold 803. The pulp 101 is held against the first male mold 802 as illustrated in FIG. 8C. Next, a second female mold 804 is mated with the first male mold 802, the second female mold having an upper edge angled downward as shown in FIG. 8D. The first male mold 802 is then removed from the pulp layer 101 by using the vacuum and optional pressurized air process described above, leaving the pulp layer 101 held against the second female mold 804 as shown in FIG. 8E. Subsequently, a second male mold 805 is mated with the second female mold 804, as illustrated in FIG. 8F. The second male mold has edges angled downward, similar to the second female mold separated by an offset, that force pulp layer 101 to curl downward as shown in FIG. 8F. As discussed above with reference to molding the cup 100 in FIGS. 1A-H, the process of mating male and female molds to create an edge may be repeated as many or as few times to obtain the appropriate edge shape and thickness. Additionally, as described above, each additional mold set may decrease the offset between the molds to thin the edge and to remove excess moisture from the pulp. As also described above, the process may include varying offset within individual mold sets and alternating offset between subsequent mold sets to decrease defects. It should be noted that the shape of the edge formed in FIGS. 8A-8F is only an example of one shape of an edge that can be formed. Any suitable edge to a cup or container may be formed using the above process, including, but not limited to an inward edge, an angular edge, and a stepped edge. Moreover, an edge may be formed simultaneous to molding the cup, rather than after the cup is molded. This can decrease manufacturing time.
Still other embodiments of the present disclosure include processes for forming a container with a reverse draft. As described above, a reverse draft feature is one whose angle runs against the draw of the mold. FIGS. 9A-F illustrate a reverse draft feature molded on a cup lid. However, it should be noted that the process for molding a reverse draft feature may apply to any paper container feature having a negative draft angle.
FIGS. 9A-C illustrate sequential steps of an embodiment of a process for forming a molded pulp lid with a reverse draft. FIG. 9A, more specifically, is a schematic cross-sectional view of the first stage of the process of forming a lid 900 with a flange 911 that will include reverse draft features (discussed in greater detail below). A wet pulp layer 901 is held against a first male mold 902 using a vacuum. A first female mold 903 is mated with the first male mold 902, the two molds having an offset. The first male and female molds 902 and 903 begin the molding of the flange 911 on the horizontal axis.
FIGS. 9B and 9C illustrate the next steps of the molding process in which the flange 911 is pressed from the horizontal axis to the vertical axis. The first male and female molds are removed from the pulp layer 901 in any one of the processes described above for forming a cup, i.e., vacuuming the pulp layer to one mold and concurrently applying pressurized air from the mated mold while it is removed. Next, as shown in FIG. 9B, a second male mold 904 and second female mold 905, having a smaller offset than the first molds 902 and 903, are mated around the pulp layer 901. The second molds 904 and 905 include portions angled between the horizontal and vertical axis to bend the flange 911 to an intermediate position between the horizontal orientation and vertical orientation. During the next sequential step shown in FIG. 9C, the second male and female molds 904 and 905 are removed using any of the methods described above and a third male mold 906 and third female mold 907 are mated around the pulp layer 901, the third molds having a smaller offset than the second molds. The third molds further move and bend the flange 911 into the vertical orientation. The molds are then removed from the pulp layer 901. Again, removal of the molds may include anything in accordance with the methods described above.
As shown in FIG. 9D, the flange 911 connects to the body of the lid at a radially inward portion forming an intersection. The sequential bending of the flange 911 at this intersection from the horizontal orientation to the vertical orientation compresses the pulp material on the underside of the flange at the intersection, which causes the fibers of the pulp to bunch together, forming a projection, such as a bump 910, that extends radially inwardly to create a reverse draft feature. FIG. 9D is a cross-sectional view of the pulp layer during stages of the molding process including a magnified view of the corner portion of the reverse draft feature. The magnified image illustrates the bump 910, caused by the bunching of pulp at the flange intersection while forming the reverse draft feature 911 (FIGS. 9A-C). The bump 910 creates the reverse draft that allows a molded pulp lid to connect or snap onto a lip area of container, e.g., a rolled rim of cup.
In the process described above, three sequential male and female molds move the reverse draft feature from a horizontal plane to the vertical plane, thereby creating the bump 910 at a negative draft angle. However, it should be noted that more or less pairs of molds may be used to create a reverse draft feature. For example, each sequential pair of molds may change the angle of a pulp layer only a few degrees until the desired reverse draft feature is obtained. As discussed above, each additional mold set decreases offset to apply force to the pulp and extract excess moisture. Additionally, the offset may be varied within individual molds and alternate between sequential molds in order to decrease the defects transferred to the pulp.
In additional embodiments illustrated in FIGS. 9E and 9F, the flange 911 is molded to provide additional reverse draft features, which are illustrated as a plurality of pleats 912 and/or protrusions 913. When the flange is in the horizontal position, the pleats 912 are generally in an open configuration with a generally V-shape cross-section described above may include pleats. During the sequential bending of the flange 911 from the horizontal orientation to the vertical orientation described above, the pleats 912 pinch together from the open V-shaped configuration to a closed orientation. FIG. 9F illustrates a perspective view of the lid 900 after the final stage of molding, wherein the pleats 912 are collapsed so as to extend radially inwardly to form reverse draft features. The molded pleats 912 create a reverse draft, so as to supplement the bump 910 created during compression of the pulp as discussed above, so that it may firmly attached to the container and remain firmly in position during use. When the lid 900 is in a relaxed position (i.e., not yet snapped onto the lip of the cup), the flange 911 (in the vertical orientation) lid has a reduced circumference or diameter. When the lid is snapped onto the rim of the cup, the molded pleats allow the flange to radially expand to a slightly larger circumference or diameter to fit over the rim of the cup (or other selected container). Once, the lid has been fully snapped onto the rim of the cup, the molded pleats return toward the relaxed position, with the flange in the vertical orientation so that the flange fits over and is positioned with the reverse draft features at least partially radially inward of the rim of the cup, firmly securing the lid onto the rim of the cup. Additionally, the pleats 912 facilitate removal of the male and female molds from the pulp layer because they can expand in response to any force exerted on the reverse draft feature. The memory of the pleats causes the circumference of the lid to collapse back into the desire reverse draft shape after the molds are removed.
An additional embodiment in accordance with the present disclosure includes a process for forming a pulp product or a portion of a pulp product with a less dense construction, referred to as a puffed pulp construction. In some embodiments, this puffed pulp construction can be used to form portions that will elevate a reverse draft feature, such as on a container or a lid. FIGS. 10A-D are schematic cross-sectional views showing an embodiment of forming the puffed pulp construction. More specifically, FIG. 10A illustrates the first stage of the process of forming a puffed pulp construction. A male forming tool 1002 is submerged into a pulp slurry 1000. A vacuum is applied to the male forming tool 1002 to attach a layer of pulp 1004 to the male forming tool 1004. A female pressing tool 1006, positioned above the pulp slurry 1000 and can apply pressurized air.
FIGS. 11B-C illustrate removal of the pulp layer 1004 from the pulp slurry 1000. Male forming tool 1002 is lifted above the pulp slurry 1000, e.g., manually or mechanically. Pressurized air can be applied to male forming tool 1002 while a vacuum is applied to the female pressing tool 1006. This holds the pulp layer 10004 against the female pressing tool 1006, so that the male forming tool 1002 can be removed. As shown in FIG. 10C, once the male forming tool 1002 is removed, a male pressing tool 1008 is introduced to the process.
As illustrated in FIG. 10D, in the subsequent step, the male pressing tool 1008 is mated with the female pressing tool 1006. Both the female and male pressing tools 1006 and 1008 include a portion with an expanded region, i.e., greater offset D, that forms the puffed pulp construction. A vacuum is applied to both the male and female pressing tools 1006 and 1008, thereby creating a less dense pulp in the expanded region. Heat can also be added to one or both of the pressing tools during the formation of the less dense pulp. After formation, the less dense and, consequently, softer puffed pulp configuration facilitates removal from the pressing tools while retaining enough memory to create an engaging force having a reverse draft.
This process of molding a pulp product with the puffed pulp process can be used to provide a wide range of products, including containers with or without lids. For example, the puffed pulp configuration can be used when forming a lid to provide a reverse draft feature that can engage a rim of a cup or other container. FIG. 11 shows a cross-sectional view of a puffed pulp reverse draft feature 1111 in accordance with an embodiment of the disclosure. The advantage of the puffed feature is that it allows a container part, e.g., a lid, to snap onto an adjoining rim of a container, e.g., a cup. This puffed pulp construction may be formed in conjunction with any of the processes described above.
All of the above processes may include heating the male and/or female mold. Heating the molds during the vacuum and the pressurized air application stages of the process facilitates a more rapid removal of the moisture from the pulp by turning it into steam. Adding heat is also advantageous in containers having a reverse draft feature as described above because it increases the memory of the pulp, thereby making it easier for the pulp layer to collapse from its horizontal orientation to its desired position after removal from the molds.
In each of the above embodiments, subsequent processes may be applied to the molded containers. For example, the containers may be printed, coated with a waterproof coating, and die cut. A coating may be applied to the containers while a vacuum holds a pulp layer against either the male or female mold. This has the additional advantage of assisting the coating in adhering to the container because the vacuum operates through the pours of the pulp paper container. The processes may further include applying a smooth and pleasing surface by using heat and press-in-place techniques. In additional embodiments, other surfaces and/or textures can be added to the container.
Each of the pulp molding processes described above may be performed by machines. These machines may include linear distribution lines wherein pulp layers are molded between male and female molds along an assembly line. The machines may also include circular revolving molds. It should be noted that any suitable machine for sequentially molding pulp into a container may be used to accelerate the process.
With reference to the annexed drawings the preferred embodiments of the present invention will be herein described for indicative purpose and by no means as of limitation.
Reference is now made to FIGS. 12 and 13, which show, respectively, top and bottom perspective view of a disk storage tray, shown generally as 10, for a disk, shown generally as 18 as a notional CD, BD, or DVD, in accordance an embodiment of the present invention. The tray 10 includes first and second tray portions 12 a, 12 b, which are constructed from a molded cellulose pulp material, such as molded cardboard or paper, and which together, define a top face or side 14 and a bottom face or side 16 of the tray 10.
The tray portions 12 a, 12 b are pivotally, and preferably resiliently, connected to one another by connector 20 disposed therebetween. For the embodiment shown, the connector 20 is a crease or fold 20 formed in the cellulose pulp material and which extends contiguously adjacent and between the tray portions 12 a, 12 b from one tray side 22 to the other tray side 22. More specifically, the crease 20 is of lesser thickness and rigidity than the tray portions 12, such that than the tray portions 12 a, 12 b can pivot thereon relative one another. Thus, for the embodiment shown, the tray 10, including tray portions 12 and connector 20, are formed from a single piece of molded cellulose pulp material, with the connector 20 extending generally centrally between the tray portions 12. It should be noted, however, that the connector could be formed from hinges or other pivotal connection means.
Preferably, the tray portions 12 a, 12 b are mirror images of one another and, preferably, are sized and shaped such that at least a portion, and preferably the entire surface area, of the disk 18 can be completely seated on the tray 10 with the top side 14 extending thereunder. Additionally, the trays portions 12 are, preferably, rectangular in shape, thus rendering the overall tray 10 preferably rectangular in shape.
Referring now to FIGS. 1, 2, 3, and 4, the tray 10 has first and second generally opposed central portions or ridges 26 a, 26 b extending, respectively, across the first and second tray portions 12 a, 12 b contiguously adjacent the connector 20 from first tray side 22 a to second tray side 22 b. Each central ridge 26 is indented inwardly, forming a corresponding central indentation 26 for the ridge 26. First and second generally opposed, and preferably semicircular, flanges or posts, generally 30 a, 30 b, protrude, respectively, upwardly from the top side 14 adjacent the connector 20 and flare angularly outwardly relative the connector 20. The posts 30 are also preferably centrally situated adjacent tray sides 22 and ends 38, and therefor are preferably disposed generally centrally on the tray 10. Corresponding post indentations 32 for the posts 30 are formed in the bottom side 16. Each post 30 generally has an outer post face or wall 34, preferably round and semi-circular in shape, that extends, outwardly and upwardly from the top side 14 and slantingly outwardly and upwardly relative the connector 20, from an intersection with the top side 14 to an outer top edge 36 of the post 30. Thus, the outer post wall 34 of each post 30 on each tray portion 12 extends, at the outer top edge 36 laterally further away from the connector 20, i.e. further towards tray end 38 on the respective tray portion 12, than it does proximal the top side 14.
Reference is now made to FIGS. 3 and 4. As shown, from an extended configuration, shown generally as 42, the tray portions 12 can be pivotally moved on connector 20 in direction D1 towards one another on the top side 12 to place the tray 10 in a retracted configuration, shown generally as 40. Conversely, from the retracted configuration 40, the tray portions 12 can be pivotally moved on connector 20 in direction D2 away from one another on the top side 12 to place the tray 10 in the extended configuration 42, in which the tray portions 12 extend generally colinearly end-to-end, i.e. at substantially 180 degrees relative one another. In other words, the tray portions 12 can be pivotally folded and unfolded on connector 20 between, respectively, retracted configuration 42 and extended configuration 40, the tray portions 34 on top side 14, and notably the posts 30 being moved proximal one another for the retracted configuration 40 and away from each other for the extended configuration 42.
The posts 30 are spaced part from one another and positioned such that, when the tray 10 is in retracted configuration 40, the outer top edges 36, 36 are at a lesser distance X1 than the diameter X3 of disk aperture 44. Thus, in the retracted configuration 40, the posts 30 may pass between circular disk inner rim 46, and thereby through the disk aperture 44 defined by the rim 46. Accordingly, when the tray 10 is in the retracted configuration 40, the disk 18 can be removed from the tray 10 or seated thereon and the posts 30 extended through the aperture 44. Conversely, the posts 30 are also spaced apart and positioned such that, in the extended configuration 42, the outer top edges 36, 36 are at greater distance X2 from one another than diameter X3 and the outer post walls 34 are spaced apart one another adjacent the top side 12 at a distance approximately equal to or slightly less than X3. Thus, when the tray 10 is in the extended configuration 42, a disk 10 previously inserted thereon in the retracted configuration 40 with the outer posts walls 34 extending through the aperture 44 cannot be removed as the walls 34 extend through the aperture 44, generally in snug abutment with the disk inner edge 46 proximal the top side 14 and overlaying the disk inner edge 46 at outer top edges 36. Specifically, in the extended configuration 42, the top outer edges 36 prevent passage of posts 36 through aperture 44 of disk 18.
In use, to seat a disk 18 on the tray 10, the tray portions 12 are moved slightly, i.e. vertically flexed, in direction D1 to place the tray 10 in the retracted configuration 40 such that the posts 30 are radially compressed towards one another to pass through aperture 44 as described above. The tray portions 12 are then moved in direction D2, i.e. flattened, to place the tray 10 in extended configuration 42 in which posts 30 are radially expanded to prevent removal of disk 18, as described above. To remove the disk 18, the tray portions 12 are again moved slightly in direction D1 to place the tray 10 in the retracted configuration 40, such that the posts 30 can pass through aperture 44.
Advantageously, as the ridges 26 are indented within the bottom side 16, they are raised, i.e. elevated, relative any generally planar surface 50 upon which the bottom side 16 of tray 10 may rest. Thus, when the tray 10 is placed on the surface 50, say a table top or shelf, with the bottom side 16 facing the surface 50, the ridges 26, posts 30, and connector 20 are spaced apart, and notably elevated, relative the surface 50. Accordingly, by simply applying a force F on the posts 36 or on the connector 20 between posts 36, a user may cause the tray portions 12 to pivotally flip towards one another in direction D1 as the connector 20 and posts 36 move towards the surface 10, thus placing the tray 10 in the retracted configuration 40 to enable seating and removal of the disk 18. To return the tray 10 to the extended configuration 42, a user has simply to release the force F, allowing gravitational force to move tray portions 12 in direction D2. Use of the resilient crease 20, biasing in direction D1 as connector 20 further facilitates placement of the tray 10 back and forth between extended and retracted configurations 40, 42. Conveniently, respective inner post wall 52 of each post 30 also flairs outwardly and angularly away relative the connector 20, thus reducing risk that these walls 52 will prevent movement in direction D1, for example by being blocked by a user's finger, which might impede placing of the tray 10 in the retracted configuration 40.
Optionally, but preferably, the tray 10 has two pairs of first and second support legs, generally 54 a, 54 b, extending outwardly on the bottom side 16 at the ridge 26, and forming leg indentations 56 in the top side 14. The support legs 54 a, 54 b of each pair are generally opposite and facing one another with the connector 20 extending adjacently therebetween, each pair of legs 54 being situated preferably adjacent a tray side 22 with the posts 30 situated between the pairs. As opposed to posts 30, the support legs 36 flair, i.e. are slanted, angularly inwardly from the bottom side 16 towards the connector 20 and have rounded leg ends 58. The legs 54 a, 54 b provide additional space between the posts 30 and connector 20 and surface 50 and thus provide additional room for connector 20 and posts 30 to move towards surface 50 when force F is applied. Thus, the legs 54 provide for additional movement of tray portions 12 in direction D1 and facilitate such movement towards the retracted configuration 40 on surface 50. Further, as the posts 30 a, 30 b are compressed towards one another by movement of tray portions 12 in direction D1, the legs 54 a, 54 b, and notably rounded leg ends 58 of each pair move away from one another, facilitated by rounded character of leg ends 58. Due to slanted configuration of the legs 54, when the tray 10 on surface 50 is in retracted configuration 40, the legs 30 extend generally perpendicular the surface 50, providing firm support for the tray 10 thereon and facilitating removal and seating of disk 18 thereon. At the same time, once the force F is released the support legs 30 are moved back towards one another as tray portions 12 move in direction D2 driven by gravitational force or by user. Thus, the legs 54, in combination with the connector 20 and posts 30, provide a spring flex mechanism for moving the tray between extended and retracted configurations 42, 40.
Reference is now made again to FIGS. 1, 2, 3, and 4. Optionally, but preferably, the try 10 has a, preferably circular, disk cavity, shown generally as 60, formed on the top side 14 and which is of similar, but slightly larger circumference than disk 18. The disk cavity 60 consists of a lower cavity floor 70 extending outwardly from ridges 26, but slightly therebelow, to generally semicircular outer cavity walls 72 of semicircular perimeter protrusions 74, one for each tray portion 12. Each perimeter protrusion 74 has a corresponding perimeter protrusion indentation 76 formed on the bottom side 14. The outer cavity walls 72 slope, i.e. slant, preferably outwardly relative the posts 30. Each perimeter protrusion 74 has and outer cavity wall 72 has first and second elevated sections 80 situated proximal tray side 22 and an intermediate recessed section 82 extending between elevated sections 80 but recessed compared to the elevated sections 80. The slanted outer cavity wall 72 at elevated sections 80 guides the outer disk 78 upwardly away from top side 14 when the tray portions 12 are moved in direction D1 and limits passage of dust and dirt under the disk 18 when seated on the tray 10. The recessed section 82 facilitates use of a user's finger on outer disk edge 78 to grasp disk 10. At the same time, support protrusions 62 on ridges 26, generally spaced circumferentially around posts 30 but extending from top surface 14 generally below posts 30, support inner ring of disk 62 while keeping outer ring 64 of disk 18 slightly spaced apart from ridges 26 and wall 72. Support protrusions 62 also have corresponding support protrusion indentations 68 in bottom side 16.
An additional outer cavity 84 on each tray portion 12 may extend on top side 14 from the perimeter protrusion 74 between tray side 22 to tray end 38. Tray side wall ridges 92 and tray end wall ridges 94 on top side, and corresponding indentations 96 and 98 may be, respectively, formed at tray sides 22 and tray ends 38. In particular, tray side wall ridges 92 provide side walls 92 which may abut one another in extended configuration 42, thus preventing excessive movement in direction D2.
The tray 10 is manufactured by molded pulp forming of the cellulose pulp in the retracted configuration 40, which helps to avoid creation of any difficult to manufacture reverse angles. Specifically, this forming technique allows for forming of the tray 10, including all of the posts 30, legs 54, protrusions 54, 62, ridges 26, connector 20, and any corresponding indentations 28, 32, 56, 68, 76, cavities 60 described above, in the positive and not the negative. Advantageously, as the tray 10 is constructed of a single molded piece of cellulose pulp, with each post 30, legs 65, protrusion 54, 62, and ridge 26 having corresponding indentations 28, 32, 56, 68, 76, the tray 10 can be formed by simply interposing of top and bottom molds, not shown, having corresponding mold protrusions and indentations onto the pulp and subsequently curing the pulp to form the tray 10 in the molds.
Although the present disk holding tray has been described with a certain degree of particularity, it is to be understood that the disclosure has been made by way of example only and that the present invention is not limited to the features of the embodiments described and illustrated herein, but includes all variations and modifications within the scope and spirit of the invention as hereinabove described.
From the foregoing, it will be appreciated that specific embodiments of the disclosure have been described herein for purposes of illustration, but that various modifications may be made without deviating from the disclosure. Furthermore, aspects of the disclosure described in the context of particular embodiments may be combined or eliminated in other embodiments. Further, while features and characteristics associated with certain embodiments of the disclosure have been described in the context of those embodiments, other embodiments may also exhibit such features and characteristics, and not all embodiments need necessarily exhibit such features and characteristics to fall within the scope of the disclosure. Accordingly, the disclosure is not limited, except as by the appended claims.

Claims

1. A process for making a molded pulp disk tray comprising:

disposing a pulp layer on a first mold;

mating a second male mold with the first mold, the first and second molds being separated by a first offset and configured to exert a compressive force on the pulp layer to remove moisture and thin the pulp layer;

drawing a vacuum through the second mold, the vacuum being configured to hold the pulp layer against the second mold;

removing the first mold from the second mold and the pulp layer;

mating a third mold with the second mold, the second and third molds being separated by a second offset, less than the first offset and configured to exert a compressive force on the pulp layer to further thin the pulp layer;

drawing a vacuum through one of the second and third molds, the vacuum being configured to hold the pulp layer against the one of the second and third molds; and

removing the other one of the second and third molds from the one of the second and third molds with the pulp layer thereon.

2. The process of claim 1 wherein the pulp layer is first disposed on a forming mold, mated with the first mold, and the forming mold is removed by drawing at least one of a vacuum through the first mold and pressurized air through the forming mold.

3. The process of claim 1, further comprising:

applying pressurized air through at least one of the first and third molds when they are removed from the second mold.

4. The process of claim 1 wherein the first offset is greater in upper portions of the first and second molds and smaller in lower portions of the first and second molds, the process further comprising:

varying the portions of subsequent male and female molds having a greater offset; and

decreasing the size of subsequent offsets.

5. The process of claim 1, further comprising:

repeating the mating and removing of subsequent molds until the container is a desired thickness and shape.

6. The process of claim 1, further comprising:

repeating the mating and removing of subsequent molds;

alternating the mold on which the vacuum operates to hold the pulp layer.

7. The process of claim 1, further comprising:

mating a fourth mold with the second mold, the pulp layer having a portion extending beyond the fourth mold;

drawing a vacuum through the fourth mold, the vacuum being configured to hold the pulp layer against the fourth mold;

removing the second mold;

mating a fifth mold with the fourth mold, the fifth mold having an upper portion configured to mold the portion of the pulp layer extending beyond the fourth mold at least partially against the fourth mold; and

repeating the mating and removal of subsequent mating molds configured to mold the portion of the pulp extending beyond the fourth mold at least partially against the subsequent mating molds.

8. The process of claim 1 wherein first, second and third molds each have a draft angle, the draft angle configured to prevent the pulp layer from tearing when it is removed from at least one of the first, second and third molds.

9. The process of claim 1 wherein first, second and third molds have at least one indentation configured to form at least one pleat on the container.

10. The process of claim 1 wherein the first, second and third molds have a plurality of indentations configured to form a plurality of pleats on a circumference of the pulp layer, the process further comprising:

molding a plurality of pleats about a circumferential portion of the pulp layer, wherein at least a portion of the pleats provides a reverse draft feature positioned at a negative draft angle.

11. The process of claim 10 wherein at least one of the first, second and third molds has a reverse draft portion with a greater porosity and a greater offset than the remainder of the mold, the reverse draft portion being configured to create a less dense pulp portion.

12. The process of claim 1 wherein the first, second and third molds are configured to imprint a pattern onto the pulp layer.

13. The process of claim 1 wherein first, second and third molds include angular lower portions, the angular lower portions configured to form stability features on the paper container.

14. The process of claim 1, further comprising:

heating at least one of the first, second and third molds during mating.

15. The process of claim 1, further comprising:

heating at least one of the first, second and third molds while a vacuum is applied to hold the pulp layer against it; and

applying a coating to the pulp layer.