Formation of contoured finished flexible articles from flatter fibrous intermediate parts

Abstract

An apparatus and method for forming three-dimensional articles is provided. [Solution] The present invention is a method for forming a fibrous molded article, the method including providing an aqueous slurry containing a plurality of fibers; providing the slurry in a dewatering chamber to remove at least a portion of a quantity of water from the slurry and achieve an intermediate form; removing the fibrous intermediate form from the dewatering chamber and placing the fibrous intermediate form in a press having a first mold portion and a second mold portion, at least one of the first or second mold portions including undulations; applying at least one of heat and pressure to the press so as to cause at least interfiber bonding or chemical crosslinking of the fibers; and removing the three-dimensional solid fibrous molded part from the press.

Description

[Technical Field]

[0001] Priority claims This application claims the benefit of U.S. Provisional Patent Application No. 63 / 425,768, filed November 16, 2022, which is incorporated herein by reference in its entirety.

[0002] The field of the invention is apparatus and methods for forming three-dimensional articles, and more particularly, for forming a solid fibrous three-dimensional article from an aqueous slurry containing a plurality of fibers into a substantially flat or slightly contoured intermediate part, and then, in a post-forming operation, changing the shape of the formed fibrous intermediate part to a second shape. [Background technology]

[0003] Current processes for making flexible articles, such as clothing, footwear (e.g., shoe uppers), bags, furniture, medical supplies, cleaning tools and consumables, toys, automotive interior parts, cases and housings for home appliances, and other flexible articles, are often wasteful and involve multiple steps. Within each manufacturing step, there are separate, inefficient, labor-intensive processes that often require transporting materials between steps. Scrap material (e.g., fabric that was cut but not used) is often simply discarded, adding to the waste in the process. Additionally, creating molds for highly contoured items is often expensive and requires complex equipment, requiring, for example, multiple moving parts. It has also been found that certain flexible articles, particularly highly contoured flexible articles, are assembled from multiple parts. It has also been found that highly contoured flexible articles often do not stack well and are expensive to transport. These and other deficiencies in the prior art are addressed by the present invention, as disclosed herein. Summary of the Invention

[0004] According to one aspect of the present invention, a method for forming a fibrous molded article includes providing an aqueous slurry containing a plurality of fibers; providing the slurry in a dewatering chamber to remove at least a portion of a quantity of water from the slurry to achieve an intermediate form; removing the fibrous intermediate form from the dewatering chamber and placing the fibrous intermediate form in a press having a first mold portion and a second mold portion, at least one of the first or second mold portions including undulations; applying at least one of heat and pressure to the press to cause at least interfiber bonding or chemical crosslinking of the fibers; and removing the three-dimensional solid fibrous molded part from the press.

[0005] According to another aspect of the invention, the slurry is in the form of a mixture, a foam, or a homogeneous suspension after mixing.

[0006] According to a further aspect of the invention, the slurry comprises at least one type of fiber selected from natural fibers, semi-synthetic fibers, and synthetic fibers.

[0007] According to a further aspect of the invention, the slurry comprises at least one type of fiber selected from natural fibers, semi-synthetic fibers, and synthetic fibers.

[0008] According to a further aspect of the invention, the slurry comprises two or more types of fibers selected from natural fibers, synthetic fibers, semi-synthetic fibers, and synthetic fibers.

[0009] According to a further aspect of the invention, the slurry comprises bio-based molecules or polymers, including, for example, chitosan, starch, ionic starch, cellulosic materials such as, but not limited to, carboxymethyl cellulose, nanofibrillated cellulose, nanocellulose, natural rubber latex, collagen, gelatin, alginate, polylactic acid, polyglycolic acid, and / or polyhydroxyalkanoates.

[0010] According to yet another aspect of the present invention, at least one of the first mold section and the second mold section includes at least one of an undulation, a texture, and a pattern imparted onto the three-dimensional solid fibrous molded part.

[0011] One advantage of the present invention includes reducing mold costs by making the mold flatter and requiring less material.

[0012] Another advantage of the present invention includes reducing the complexity of the mold set by reducing the need for separable or flexible elements or by reducing the number of parts in the mold.

[0013] Further advantages of the present invention include a greater ability to stack partially fabricated items together for transport or storage prior to use.

[0014] These and other advantages will be apparent to those skilled in the art in light of this disclosure and drawings.

[0015] These and other features of the present disclosure will be more readily understood from the following detailed description of the various aspects of the disclosure, taken in conjunction with the accompanying drawings illustrating various embodiments of the disclosure. [Brief explanation of the drawings]

[0016] [Figure 1] 1 shows a schematic setup for adding at least a portion of the desired components of the slurry to a mixer. [Figure 2A] 1 illustrates one embodiment of a generally rectangular dewatering chamber intended to produce a substantially flat dewatered fibrous sheet. [Figure 2B] 1 shows another embodiment of a generally rectangular dewatering chamber intended to produce an undulating dewatered fibrous sheet. [Figure 3] An image of a dehydrated flat sheet is shown. [Figure 4]1 shows a schematic exploded view of an embodiment of a press chamber intended to press on a dewatered flat sheet double-door shoe upper. [Figure 5] 10 shows a schematic diagram of the steps of removing the double shoe upper from the press chamber and performing a secondary operation. [Figure 6] 1 is a photographic image of an example of an intermediate form of a shoe upper. [Figure 7] 1 is a photographic image of an example of an intermediate form that has been transformed into its final shape and attached to additional components to form a finished shoe. DETAILED DESCRIPTION OF THE INVENTION

[0017] Referring now to Figures 1-7, the present invention is an article 10, which is a three-dimensional solid fibrous molded part 12 containing at least one contour, and a method for making the article. The three-dimensional solid fibrous molded part 12 is first formed into an intermediate form 14 and then, in a secondary operation, transformed into a final shape and, optionally, attached or otherwise secured to additional components. Typical articles formed using the methods and apparatus disclosed herein include, but are not limited to, footwear, clothing and various other apparel, bags and various other accessories, automotive interiors and parts, consumer goods, furniture interiors, and soft medical products. Examples of footwear include, but are not limited to, shoe uppers. Examples of clothing articles include, but are not limited to, shirts, shorts, gowns and other medical garments, dresses, skirts, pants, socks, vests, sweaters, scarves, hats, gloves, mittens, and underwear. Examples of bags include, but are not limited to, handbags, wallets, backpacks, book bags, satchels, and clutches. Examples of automotive interior parts include, but are not limited to, interior panels, interior trim, seat covers, floor mats, dashboard covers, and steering wheel covers. Examples of consumer goods include, but are not limited to, laptop / computer housings, flexible circuit board covers, phone cases, flexible cleaning products, and feminine hygiene products. Examples of furniture interiors include, but are not limited to, chair and couch covers, and wall coverings or panels. Examples of soft medical products include, but are not limited to, bandages and various other covers, slings, and various other stabilizing elements, including soft articles for use within the body.

[0018] While the present disclosure is directed to making shoe uppers in accordance with the present invention, those skilled in the art will understand that the teachings herein can be used to make any of the above articles (or the like) without departing from the spirit or scope of the present invention. The above list of articles is intended to be exemplary and non-limiting.

[0019] The present invention includes a solid molded fiber part 12 formed from an aqueous slurry (hereinafter "slurry 20") containing a plurality of fibers 16. The slurry 20 can include natural fibers, semi-synthetic fibers, synthetic fibers, or combinations thereof. Natural fibers include wood fibers, plant fibers, and animal fibers. Wood-based fibers include, but are not limited to, bleached and / or unbleached and / or recycled hardwood and / or softwood fibers. Plant-based fibers can include, but are not limited to, cotton, flax, hemp, jute, ramie, bamboo, sisal, abaca, kapok, coir, and general agricultural waste. Animal fibers can include, but are not limited to, wool, silk, cashmere, alpaca, llama, mohair, yak, camel hair, chivito, vicuna, angora, and horsehair. Semi-synthetic fibers can include, but are not limited to, cellulosic fibers such as rayon, viscose, modal, Tencel, lyocell, and acetate. Synthetic fibers may include, but are not limited to, polyester, nylon, olefin, spandex / elastane, acrylic, PVC, aramid, and microfiber. Additionally, sustainable synthetic fibers such as polylactic acid (PLA) fibers and polyhydroxyalkanoate (PHA) fibers may be used. One or more fiber types may be added, and any other components, such as, but not limited to, bio-based and / or synthetic molecules / polymers and additives, may be added to the materials used either before forming (while in a fluid state), after the material has dried, or after the item (or portion of an item) has been formed. Bio-based molecules / polymers may be added as binders and / or retention agents to enhance the wet and dry strength of the solid fibrous molded part 12. These bio-based molecules / polymers include, but are not limited to, chitosan, starch, ionic starch, cellulosic materials such as, but not limited to, carboxymethylcellulose, nanofibrillated cellulose, nanocellulose, natural rubber latex, collagen, gelatin, alginate, polylactic acid, polyglycolic acid, and polyhydroxyalkanoates.Additionally, synthetic molecules / polymers and synthetic molecules / polymers with a certain amount of bio-based carbon can be used in the material to improve mechanical strength, such as, but not limited to, polyurethane emulsions, thermoplastic materials, and resins such as polyaminoamide-epichlorohydrin (PAE). One suitable slurry is disclosed in U.S. Patent Application No. 17 / 466,792, the disclosure of which is incorporated herein by reference.

[0020] Referring to FIG. 1 , a slurry 20 can be made by combining fiber 16, water 26, and any other desired ingredients in a mixer 28. FIG. 1 illustrates an exemplary setup in which a series of raw material sources 30 are in communication with the mixer 28, allowing amounts of various raw materials to be provided (e.g., pumped or gravity-fed) into the mixer 28 as desired. In the illustrated example, up to six raw material sources 30 are provided. Additionally, a water source 32 and a fiber 16 source are also provided for adding desired amounts of fiber 16 to the mixer 28. Upon entering the mixer 28, the ingredients are generally mixed until all ingredients are thoroughly mixed and / or dispersed, and the slurry takes the form of a mixture, foam, or homogeneous fiber dispersion. An example of the above-described slurry may contain, but is not limited to, the following contents: water (20-99.99%), fiber (0.0075-60%), and other additives (0.0025-20%).

[0021] Referring now to FIGS. 2A and 2B, once mixed to the desired consistency, the slurry may be poured, pumped, gravity-fed, or provided by any other known means into the dewatering chamber 18. The screen may be flat (see FIG. 2A) or may include at least one contour (see FIG. 2B). The dewatering chamber 18 is comprised of walls 22, a bottom screen 23, and a container for collecting waste liquid. The screen has openings 25 that generally prevent at least fibers 16 from the slurry 20 from exiting the dewatering chamber 18 while allowing at least a portion of the water 26 from the slurry to drain, effectively causing dewatering. After the slurry has been dewatered to the desired extent, a substantially flat or contoured fibrous material 24 is obtained and removed from the dewatering chamber 18. The dewatering chamber 18 can be 3D printed or fabricated from PVC, nylon, and wood materials. An example of a fibrous cuboid material removed from the dewatering chamber is shown in FIG. 3.

[0022] After removal from the dewatering chamber 18, the fibrous material may be substantially flat, or the contoured material may optionally be further dried. To achieve the desired intermediate form 14, the substantially flat or contoured fibrous material 24 is then formed in a pressing operation.

[0023] Referring now to FIG. 4 , the substantially flat or contoured fibrous material 24 can be placed in a press 34 including a first mold portion 36 and a second mold portion 38. For example, one of the mold portions is typically a positive mold and the other a negative mold. However, the invention is not so limited; for example, the mold portions may be partially negative and partially positive. When the substantially flat or contoured fibrous material 24 is pressed between the first and second mold portions, the substantially flat or contoured fibrous material 24 undergoes a shape change. Furthermore, the application of pressure, and optionally heat, causes fiber-to-fiber, polymer-to-polymer, and / or polymer-to-fiber bonding and chemical crosslinking to create a material with desired structural stability. The first and second mold portions 26, 28 can be 3D printed or fabricated from metal. The first and second mold sections 26, 28 may also include additional undulations, textures, and / or patterns that leave desired surface effects in the final three-dimensional solid fibrous molded part 12.

[0024] In an alternative embodiment, not shown, a substantially flat or contoured fibrous material 24 can be bladder pressed against a single 3D printed or metal mold part. In a further embodiment, it may be desirable to achieve a substantially flat or contoured fibrous material 24 by forming the slurry 20 into the intermediate form 14 rather than dewatering the slurry 20 and then pressing it.

[0025] Once the intermediate form 14 is achieved, further drying and / or trimming may be necessary. For example, as shown in FIG. 5, a substantially flat or contoured fibrous material 24 was pressed into a sheet with two distinct sections formed into a single sheet. While FIG. 5 shows the intermediate form 14 with two sections, the intermediate form 14 could have a single final section, or three or more final sections, without departing from the scope of the present invention. Preferably, the intermediate component 14 comprises a flatter or less contoured version of the final component, e.g., a stackable shape. For example, in FIG. 5, one section is a "gate" shoe upper and the second section is the heel of the shoe. In this shape, the product is much more stackable and potentially cheaper to ship than its final form as a completed shoe (also shown in FIG. 5). The components are then separated from the extraneous material. In embodiments in which intermediate piece 14 has multiple components therein, or is a single component but has excess material, the component(s) may be trimmed by any known means, including cutting, stamping, or trimming. Finally, the final shape and / or product can be achieved through further processing via gluing, sewing, tying, taping, or welding to another object to achieve the desired final shape / product. For example, in the example shown in FIG. 5, two molded components (a shoe upper and a shoe heel) cut from intermediate piece 14 are glued together, holes are drilled in the material for laces, and a sole is attached. The final product can include highly contoured items and include surface effects while being made with fewer components and a reduced number of manufacturing steps than traditional methods.

[0026] 1, the ingredients to the slurry 20, including at least water 26, a single type of fiber or multiple fiber types 16, and optionally additives, are provided to a mixer 28. The ingredients are mixed until the slurry 20 becomes a mixture, foam, or homogeneous suspension.

[0027] 2A and 2B, the slurry 20 is then added to the dewatering chamber 18 where some, most, or all (depending on the final product material) of the water from the slurry 20 is drained, effectively dewatering the material during the process of converting the slurry 20 to the intermediate form 14.

[0028] Referring to Figure 3, the intermediate form 14 is removed from the dewatering chamber 18 and, optionally, further dried. Next, referring to Figure 4, the intermediate form 14 is placed in a press 34 between a first mold section 36 and a second mold section 38. Pressure and / or heat are applied to the intermediate form 14 to cause fiber-to-fiber, polymer-to-polymer, and / or polymer-to-fiber bonding and chemical crosslinking to create a material with the desired structural stability. The result is a three-dimensional solid fibrous molded part 12.

[0029] 5, one or more parts can be trimmed from the three-dimensional solid fibrous molded part 12, after which secondary operations can be performed to obtain the final product. The secondary operations can be performed in the same location as other processes, or can be performed in a different, more convenient location after the three-dimensional solid fibrous molded part 12 has been shipped.

[0030] In the following claims, corresponding structure, material, acts, and equivalents of all means-plus-function or step-plus-function elements are intended to include any structure, material, or act for performing that function in combination with other specifically claimed elements. The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The embodiments were chosen and described in order to best explain the principles and practical applications of the disclosure and to enable others skilled in the art to understand the disclosure in various embodiments with various modifications suitable for the particular use contemplated.

Claims

1. 1. A method for forming a fibrous molded article, comprising: providing a slurry containing at least a quantity of water and a plurality of fibers; providing the slurry in a dewatering chamber, the dewatering chamber having a screen capable of allowing water to flow therethrough but substantially preventing the fibers from the slurry from passing through the screen; dewatering the slurry by allowing at least a portion of the quantity of water to flow through the screen until a substantially flat or undulating fibrous material is achieved; removing the fibrous intermediate form from the dewatering chamber; placing the fibrous intermediate form in a press having a first mold portion and a second mold portion, at least one of the first or second mold portions including undulations; applying at least one of heat and pressure to the press to create at least interfiber bonding or chemical crosslinking of the fibers; and removing the intermediate piece from the press, wherein the intermediate piece is comprised of a three-dimensional solid fibrous material.

2. The method of claim 1 , wherein the slurry is in the form of a mixture, a foam, or a homogeneous suspension after mixing.

3. The method of claim 1 , wherein the slurry comprises at least one type of fiber selected from natural fibers, semi-synthetic fibers, and synthetic fibers.

4. The method of claim 3 , wherein the slurry comprises at least two types of fibers selected from natural fibers, synthetic fibers, semi-synthetic fibers, and synthetic fibers.

5. The method of claim 1 , wherein the slurry comprises a bio-based molecule or polymer.

6. 6. The method of claim 5, wherein the bio-based molecule or polymer is one of chitosan, starch, ionic starch, cellulosic materials such as but not limited to carboxymethyl cellulose, nanofibrillated cellulose, nanocellulose, natural rubber latex, collagen, gelatin, alginate, polylactic acid, polyglycolic acid, and / or polyhydroxyalkanoate.

7. The method of claim 1 , wherein at least one of the first mold part and the second mold part includes at least one of an undulation, a texture, and a pattern imparted onto a three-dimensional solid fibrous molded part.

8. The method of claim 1 , wherein heat and pressure are applied in the press.

9. The method of claim 1 , wherein the three-dimensional solid fibrous molded part comprises one or more of a final part and excess material.

10. The method of claim 9 , wherein the excess material is removed from the one or more final parts.

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