WO2025147620A1

WO2025147620A1 - Composite materials and articles produced from textiles, natural fibers, and polymer resin

Info

Publication number: WO2025147620A1
Application number: PCT/US2025/010250
Authority: WO
Inventors: Robert Fleming; Ethan ESCOWITZ
Original assignee: Equilisyn LLC
Current assignee: Equilisyn LLC
Priority date: 2024-01-03
Filing date: 2025-01-03
Publication date: 2025-07-10
Anticipated expiration: 2026-07-03

Abstract

Methods for manufacturing durable goods from waste textiles, and the articles made according to the methods, are provided. In an exemplary method used textiles are obtained, sorted, washed and dried. The used textiles are cut into suitable pieces, or joined into larger sections then cut into suitable pieces, then combined with a natural fiber and a suitable resin in a mold. The resin is then cured. Curing can be photoinitiated by exposure to a suitable type of radiation, or thermally initiated by heating, or both. At least some of the mold can be transparent to the suitable radiation where the curing is photoinitiated. The natural fibers can be provided in the form of a stiffener.

Description

Composite Materials and Articles Produced from Textiles, Natural Fibers, and Polymer Resin

BACKGROUND OF THE INVENTION

[0001] Field of the Invention

[0002] The invention relates generally to the field of repurposing waste materials, and more particularly to manufacturing durable goods from waste textiles.

[0003] Description of the Prior Art

[0004] The textile and clothing industry is one of the most ecologically detrimental industries, responsible for approximately 1.2 billion tonnes CO2 equivalent of greenhouse gas released into the earth’s atmosphere. It is estimated that the large and complex supply chains, high water, energy, chemical use, and the generation of textile waste cause the textile, footwear, and clothing industries generate 8-10% of global greenhouse gas emissions.

[0005] Approximately 6% of all waste generated in the United States is comprised of used clothing, about 16 million tons annually. Discarded clothing typically is turned into rags, recycled, or enters the waste stream. The vast majority, 85% of all discarded clothing, is directed either to landfills or incineration.

[0006] A very small proportion of discarded clothing, less than 1 %, is reprocessed to make use of the fibers. One reprocessing methodology involves melting, grinding, or pulverizing used clothing to a fine powder to be converted into a low-quality fiber, or to be used as a filler. Another reprocessing methodology involves chemically dissolving, breaking down, or thermally pyrolyzing the clothing to yield a raw chemical for chemical synthesis or fuel. Both of these methods are labor and energy intensive, leading to higher costs. Sorting and transporting the discarded clothing only adds to the costs.

[0007] Fiber reinforced polymer composites, or simply “composites” herein, are a class of materials that can offer advantageous properties to manufactured components such as a high strength to weight ratio, anisotropic properties such as stiffness in one direction and flexibility in another, corrosion resistance, chemical resistance, and unique shapes and surfaces. Composites include a fiber, to provide stiffness, disposed in a matrix of a polymer. Exemplary fibers comprise synthetic fibers, polymer fibers, carbon fibers, and glass fiber. The fibers are typically in the form of a filament, roving, woven fabric, or non-woven fabric and can be randomly oriented in the matrix, or directionally aligned in the matrix, and often are laminated with alternating fiber directions. The polymer matrix comprises a cured thermoplastic or thermosetting polymer resin, or “binder.” Composites are fabricated by mixing the fibers into the resin and then curing the mixture in a mold, or layering the resin between sheets of fibers in a mold, followed by curing.

[0008] Modern manufacturing of consumer goods and the like relies heavily on process controls, starting with the raw materials. In order to reliably produce uniform products of consistent quality, manufacturers seek to start with uniform starting materials, and then process the starting materials in precisely the same way, every time. Discarded clothing as a starting material is antithetical to modem manufacturing since it is a non-uniform mixture of different natural and synthetic fibers, that have been treated with different dyes, subjected to different detergents, body oils, and other contaminants. Thus, attempts to make use of discarded clothing and other textiles have sought to avoid these drawbacks by dissolving, breaking down, or pyrolyzing the fibers, reducing the fibers to a fine powder, or using the unwanted textiles as a filler.

[0009] The most common fibers used to reinforce resins are glass and carbon fibers. These fibers work extremely well at reinforcing the matrix but are expensive and have a high carbon footprint due to the high temperatures required to make the fibers, and the extraction and purification of the precursor materials. Despite these disadvantages, glass and carbon fiber reinforced polymer composites have many successful commercial applications in automotive, marine, wind, and aerospace, for example.

[0010] Natural fiber composites, on the other hand, have been less successful due to their high moisture absorption of the fibers and poor wetting and adhesion to the resin matrix to the fibers. The moisture can interact with many metal containing catalysts used to cure thermosetting polymers, effectively poisoning the catalyst and rendering it ineffective. The hydrophilic nature of the natural fibers causes poor interfacial interaction between the polymer matrix and the fiber. It is most often required to optimize the fibers by chemical surface treatments. An additional disadvantage is the limited thermal stability of natural fibers, which limits the maximum processing temperature and resin systems that can be utilized.

[0011] Matrix resin systems used to bind the fibers can be of the thermoplastic or thermosetting type. Thermoplastic resins have the advantage that they can be remelted or shaped multiple times, the disadvantage is that the equipment required to process and mold parts is very expensive due to the high temperatures and pressures required. Thermosetting resins are reactive systems that typically start from monomers or pre-polymers and require lower processing temperatures. Thermosetting resins react and cure into a 3-dimentional molecular network that is no longer melt processable. The most commonly used thermosetting resin systems are of the vinyl ester type or the bisphenol A epoxy type. Both of these resin systems have significant health concerns. Bisphenol A epoxy contains BPA, a known endocrine disruptor, and vinyl ester resins contain styrene; an anticipated human carcinogen.

SUMMARY [0012] An exemplary method of forming an article of manufacture comprises cutting a textile, such as a used textile or scrap textile left over from a manufacturing process, into pieces and combining a piece of the textile with natural fibers and a resin in a mold, and curing the resin to form the article. In some embodiments, the natural fibers are disposed as a layer within the mold and in some of these embodiments comprises a stiffener. The resin can comprise isosorbide functionalized with an unsaturated fatty acid, an epoxy, an acrylate, a vinyl group, or an isocyanate group, in various embodiments. In those embodiments in which the textile is a used textile, the method can also comprise obtaining mixed used textiles including the used textile, sorting the mixed used textiles, washing, and drying the used textile before cutting the used textile. In further embodiments the UV transmissivity of the used textiles is measured as part of the sorting process. Pieces of used textile can be stitched around the edges or joined to other pieces of used textile before being placed in the mold. [0013] In various embodiments the mold comprises a UV transparent material and curing the resin includes exposing the resin to UV radiation through the mold. Curing can also comprise heating the article either still in the mold or after removal therefrom. Combining the piece of the waste textile and the natural fiber with the resin in the mold can also include, in some embodiments, impregnating the piece of waste textile and/or the natural fibers, with the resin before placing them in the mold. Combining the piece of the waste textile with the natural fibers and the resin in the mold includes placing the resin in the mold, then placing the piece of waste textile in the mold, then placing the natural fiber in the mold, and then placing more resin in the mold. The resin can be a thermosetting or thermoplastic polymer, and the resin can further include a photoinitiator or a thermal initiator, and in some instances the resin includes both thermosetting and thermoplastic polymers.

[0014] Curing can further comprise both exposing the resin to UV radiation through the mold combined with heating the article to yield high performance composite parts. This dual cure allows for the manufacture of thicker parts, for example, 5 mm or more in thickness, such as 10mm. The dual cure also allows articles to be cured that are highly filled with materials that are not UV transparent, such as fabric, natural fibers, and agricultural byproducts like hemp hurd or nut shells. The dual cure system also provides excellent surface finish with high manufacturing efficiency. For example, after as little as 1 minute of UV exposure on all sides, the article is sufficiently cured such that it can be removed from the mold, then curing can be completed in an oven. This allows the mold to be reused more quickly.

[0015] Articles of manufacture made by the methods of the present invention comprise a composite of a piece of a used textile and natural fibers within a cured resin.

BRIEF DESCRIPTION OF DRAWINGS

[0016] FIG. 1 is a flowchart illustrating an exemplary method for producing articles according to an embodiment of the present invention.

[0017] FIG. 2 is photograph of an exemplary strip of denim cut from a pair of jeans according to an embodiment of the present invention.

[0018] FIG. 3 is a photograph of an exemplary belt made according to an embodiment of the present invention.

[0019] FIG. 4 is a photograph of an exemplary purse made according to an embodiment of the present invention.

[0020] FIG. 5 shows a reaction of an unsaturated fatty acid with isosorbide to create an unsaturated polyester according to an embodiment of the present invention.

[0021] FIG. 6 is a photograph of an exemplary mold for an arm for sunglasses, two pieces of waste fabric and one natural fiber stiffener sized to fit the mold, according to an embodiment of the present invention. [0022] FIG. 7 is a photograph of exemplary molded left and right temple arms for a pair of sunglasses, according to an embodiment of the present invention.

[0023] FIG. 8 is a photograph of an exemplary mold for a front frame for sunglasses according to an embodiment of the present invention.

[0024] FIG. 9 is a photograph of a cut piece of a waste textile and a molded front frame made with the mold shown in FIG. 8, according to an embodiment of the present invention. [0025] FIG. 10 is a photograph of two molded front frames each with lenses according to embodiments of the present invention.

[0026] FIG. 11 is a photograph of a completed pair of sunglasses according to an embodiment of the present invention.

[0027] FIG. 12 is a photograph of a square mold and a decorative tile molded therein according to an embodiment of the present invention.

DETAILED DESCRIPTION

[0028] The present disclosure provides methods for efficiently turning waste textiles into high value articles. For instance, when an article of clothing, such as a pair of jeans or a shirt, has reached its end of life, it can be cut into shapes or strips suitable for a desired finished article, these pieces are then placed into a mold, individually or in overlapping stacks and patterns, along with natural fibers and a resin, and then cured. The result is a 3 dimensionally shaped composite product or article that can be bonded, sewn, stitched, or fastened into a finished item such as a belt, purse, backpack, hat, shoe, boot, waterproof bag, furniture, shelves, bicycle, vehicle, sunglasses, architectural tile, automotive interiors, wall board, composite panel or the like.

[0029] As used herein, a used textile is a textile that was produced for another purpose, and employed for the other purpose. Used textiles expressly excludes manufactured textiles that have not been previously used, such as fabrics specially made for forming composite materials. Used textiles are morphologically distinguishable from freshly manufactured textiles in that the fibers can be frayed and modified by exposure to various environments resulting in surface modifications such as bleaching from sunlight, exposure to chlorine, and so forth.

[0030] In this invention waste textiles can comprise used textiles such as discarded clothing including jeans, pants, shirts, jackets, skirts, dresses, and the like. The used textiles can also be from linens, bed sheets, blankets, or draperies. Further, the waste textiles can comprise scraps and left over materials from industrial applications such as upholstery fabric, industrial coverings, wall coverings, awnings, carpet, cuttings from textile manufacturing, and the like. The fibers of the waste textiles can be cotton, silk, wool, coir, kenaf, hemp, flax, bamboo, banana, protein, cellulose, nylon, polyester, acrylic, polyolefin, polyurethane, spandex and blends thereof. The waste textile can also be made of synthetic fibers produced from petroleum sources such as nylon, polyester, acrylic, polyolefin, polyurethane, nylon, spandex and blends thereof.

[0031] Suitable waste textiles can be either woven or nonwoven, though woven is preferred in some embodiments as these typically provide better modulus and break strength. The resin used to bind the fibers into the desired final shape can be thermosetting polymers, for example of the epoxy, acrylate, vinyl ester, or polyurethane type; or thermoplastic, for example of the polyamide, polylactic acid (PLA), polyurethane, or polyester type.

[0032] Combining a thermoplastic or a thermosetting resin with both woven and nonwoven pristine textiles of natural or synthetic fibers is well known in the art. It is also well known that the wetting, penetration, and adhesion of the resin to the fibers is critical to the final performance of the produced composite. Natural fibers, however, are comprised primarily either of cellulose or protein, both of which are hydrophilic, making the wetting and bonding of the hydrophobic resin difficult. It is a surprising result, therefore, that used textiles made from natural fibers and that have been worn and washed display surprisingly good wetting and adhesion to certain resins, most likely because the mechanical and chemical action of washing and wearing loosens the fiber bundles and the surfaces of the fibers are activated for wetting and bonding with the resin. When cost and performance are considered together used textile composites offer excellent advantages.

[0033] FIG. 1 illustrates an exemplary method 100 for producing articles of manufacture according to the present invention. The method 100 comprises obtaining waste textiles 110, and in those instances where the waste textiles are used textiles, optionally sorting the used textiles 120 and washing and drying the used textiles 130. Method 100 further comprises cutting the waste textiles into pieces 140, providing a natural fiber of a desired shape 145, combining a piece cut from the waste textiles with the natural fiber and a resin in a mold 150, and curing the resin to form the article 160. In various embodiments, any or all of the first three steps 110, 120, and 130 are optional.

[0034] Method 100 can be used to incorporate waste textiles into articles of manufacture such as purses, hats, shoes, boots, backpacks, waist packs, wallets, cell phone covers, eyeglass cases, book covers, raincoats, luggage, sporting good equipment, furniture, bookshelves, vehicle parts, composite panels, etc. The method 100 does not require the extra step of grinding, milling, dissolving, or breaking down the fiber which requires added cost and energy, and also damages the structural integrity of the 1'ibers. In such prior art methods, end materials may have a tensile strength ten times lower than the original material resulting in significantly lower performance at the expense of a greater amount of energy consumed. [0035] The resin can be supplied into the mold as a melted liquid thermoplastic, or as a liquid thermosetting material. Preferably the resin used is comprised substantially from biobased sources. After the resin is cured in the mold the article is removed and optionally further cured outside of the mold in an oven. The article can be further modified by sewing, stitching, gluing, bolting, screwing, or bonding to attach, for example, buckles, buttons, zippers, hinges, screws, bolts to yield a finished item.

[0036] Suitable resins should have good mechanical properties, properly wet and bond to both the natural fiber and waste textile, and have good optical properties such as optical clarity. The resin used to bind the fibers into the desired final shape can be thermosetting polymers, for example of the epoxy, acrylate, vinyl ester, or polyurethane type. The resin can also be thermoplastic, for example of the polyamide, polylactic acid, polyurethane, or polyester type. In various embodiments, the resin does not contain bisphenol A (BPA) or styrene and is a thermosetting resin of the urethane, epoxy, or acrylic type. Resins formulated from acrylate monomers, prepolymers, and urethanes that contain monomers and prepolymers from biobased sources advantageously reduce the carbon footprint of the manufactured items. In some embodiments the resin contains a UV activated catalyst and is UV cured, or contains a thermally activated catalyst and is thermally cured, or a combination of both.

[0037] It is a further surprising result that the combination of UV catalyzed and UV cured and thermally catalyzed and thermally cured formulated acrylic systems give very short cure times but also gives excellent resin penetration into the fibers as well as excellent adhesion to the fibers, resulting in a molded part with excellent stiffness and toughness and short processing times. These systems are also advantageous in that they can be processed and cured quickly at temperatures significantly lower than 200C, the temperature at which many natural fibers may start to break down.

[0038] Exemplary resins can include meltable thermoplastics such as Nylon 6, polyethylene terephthalate (PET), polylactic acid (PLA), and polyurethane. The resin can also be cross-linkable such as acrylates, epoxies, urethanes, silanes, silicones, unsaturated polyesters, and vinyl compounds. These thermoplastic or cross-linkable resins can be partially or substantially derived from biobased sources such as agricultural crops, biomass, or from fermented sources. Exemplary UV curable resins include a broad range of UV curable acrylates, such as from Arkema Sartomer, for example urethane acrylates such as CN975, CN3211, CN1964, CN9024. Exemplary UV curable resins can also include epoxy acrylate resins such as CN120, CN2602, or SR349, polyester acrylates such as CN2102E, CN973J5, aliphatic multifunctional acrylate resins such as SR351, SR9020, SR238, SR399, SR494, SR833s, bio-based UV curable resins under the Sarbio name from Arkema Sartomer such as Sarbio 7205, 7107, 7106, 6102, 6101, 6100, 5106, 5102, 5201, 5103, and 5100.

[0039] Allnex also supplies suitable commercial UV curable resins under the tradename Ebecryl, for example polyester based acrylates such as Ebercryl 876, 853, 892, 109, 110, 113 and 114, and urethane acrylates such as Ebercryl 1258, 1271, 1290, 1291. Allnex also supplies suitable biobased resins that could be used such as Ebecryl 5850, 5849, 5848, 767, 242, 4491, 4683, R1872, and IBOA. IGM Resins supplies suitable urethane acrylate resins under the Photomer tradename such a Photomer 6008, 6010, 6024, 6578, polyester acrylates, epoxy acrylates, and a line of biobased resins under the name PureOmer for example PureOmer 5433, 5437, 5443, 5450, 5662, 5850.

[0040] Unsaturated polyester or vinyl ester resins can also be employed, CN154 by Sartomer is a suitable vinylester methacrylate resin. Vinyl ester resins can be of the epoxy vinyl ester type, orthphthalic polyester type, or vinylpolyester type for example as supplied by AOCResins, the INEOS Group, or Interplast Corporation. INEOS Composites also supplies a suitable unsaturated polyester resin containing biobased materials. The resins can be cured by the photoinitiators and/or thermal initiators as described below. Cationic photoinitiators can also be employed. For epoxy resins, amine, anhydride or photocationically cured resins can also be used. For instance, a bisphenol A epoxy such as Epon 828 as supplied by Hexion can be cured with a Versamid supplied by Huntsman

Corporation. A range of epoxy resins and curing agents can be supplied by Huntsman Corporation, Hexion, DowDuPont, or Olin, for example. Epoxies used can also be obtained from biobased sources such as epoxidized soybean oils. Epoxy resins can be cured with a range of diamines or anhydrides.

[0041] Photoinitiators are added to UV curable resin to initiate polymerization, and suitable examples include Speedcure BPO, EMK, TPO, TPO-L supplied by Allnex. BASF supplies a range of suitable acrylate monomers and acrylate resins under the Laromer name, and also supplies suitable photoinitiators under the Irgacure tradename such as Irgacure 184, 819, and 907. IGM Resins supplies suitable photoinitiators under the Omnirad name such as Omnirad 184, 1173, 127, 1000, ITX, EMK, MBF, OMBB. In addition to, or in place of, the photoinitiator a thermal initiator can be employed that generates a free radical by thermal decomposition. Akzo makes a line of suitable thermal initiators of many types such as the ketone peroxide type like Butanox M-50 or the diacyl peroxide type like Perkadox GB50L or Perkadox L40, Perkadox AMBN, Perkadox AIBN, or Peroxyesters like Trigonox 421, or azobisisobutylnitrile. Arkema makes a line of thermally activated organic peroxides such as Luperox A98, Luperox LP, Luperox A75, and Luperox 10, for example. Also, iron-type catalysts under the Nouryact name by Akzo can be used. These iron type catalysts are less sensitive to moisture, unlike the cobalt type that are susceptible to poisoning by moisture.

[0042] Fillers can also be added to the resin to enhance performance, such as to impart flame resistance, modulus, or to lower cost, examples of fillers include ground up waste materials or low-cost minerals. Talc, mica, gypsum, silica, kaolin, clays, aluminum trihydrate, melamine pyrophosphate; metal oxides and hydroxides such as zirconia, and iron, magnesium, and aluminum hydroxides are examples of fillers that can be used. [0043] The mold can be made of metal, plastic, glass, ceramic, recycled materials, or combinations thereof. Molds typically comprise two pieces that mate together, and in various embodiments one or both pieces are UV transparent. But if pieces of the mold are made from a material that is not UV transparent, such pieces can include a transparent window to admit UV light. Low-cost acrylic molds are preferred in some embodiments, such as molds made of polymethylmethacrylate (PMMA). UV transparency is desirable for molds intended for use in combination with UV curable resins. Metal molds are suitable for heat conduction for use with thermally cured resins. For embodiments that combine both UV curable and thermally curable resins, metal molds with one or more transparent windows can be employed, for instance.

[0044] The desired article of manufacture can be designed in a computer automated design (CAD) software tool. From the designed article, a mold is then designed. The mold material can be steel, aluminum, glass, plastic, or a combination of these materials. The mold material is then formed into the mold by methods such as machining, 3D printing, or laser cutting/etching. Typically, the mold has a top and bottom half, the top and bottom halves of the mold can be comprised of the same material or dissimilar materials. As one example, the bottom half of the mold could be a machined aluminum and the top half could be glass or PMMA such that the part could be UV cured through the top half and then the top half of the mold is removed and the remaining aluminum bottom half of the mold and the article is further cured in an oven at a temperature higher than what can be use with PMMA molds alone. If the article is not UV cured but only thermally cured, then a conventional metal mold can be used. Mold materials are selected based on the curing methods used, curing temperature, release from the mold, and mold life (how many times a mold can be reused), and part quality. [0045] Waste textiles are obtained in step 110. The waste textiles can be obtained from a wide range of sources, for example organizations such as Goodwill that collect used clothing. Where the waste textiles that are obtained in step 110 are used textiles comprising a mixture of different articles, the used textiles can be sorted in step 120, such as by material type, color, pattern, and by size, for example. Image analysis software can optionally be used to categorize the sorted materials. The material type can be determined from affixed tags or labels, or by measured physical properties of the used textiles, or by chemical analysis methods such as infrared spectroscopy or another optical analysis. An appropriate resin formulation can be chosen for different combinations of textiles and natural fibers as different formulations may be more or less effective depending on the different constituents of the textiles and natural fibers for reasons such as adhesion and curing conditions. The color and patterning of the waste textile can impact the aesthetics of the finished article and in some embodiments will also influence the curing method and conditions. For instance, darker dyed fabrics may require a different formulation and curing condition (i.e. UV curing) than a lightly colored fabric. It may be desirable to measure the UV transmissivity of the used textiles as part of sorting in step 120.

[0046] In step 130 the used textiles are washed and dried. This can serve to remove oils and dirt that could negatively affect adhesion. Drying removes moisture that can also negatively affect adhesion and curing. Step 130 can take place before step 120, in some embodiments.

[0047] In step 140 the waste textiles are cut, or otherwise sectioned, to a desired shape. Cutting can be performed, for instance, by die cutting to repeatedly cut the same shape from the used textiles. Other methods for cutting include use of a shredder, a shearing blade, or a laser. In various embodiments the laser is computer controlled and attached to an x-y stage. In some embodiments the pieces cut from the used textiles have the same shape as a footprint of the mold into which they will be placed.

[0048] Additionally in step 140, once the textile is cut into its desired shape, it may be advantageous to add stitching or printing for cosmetic reasons but also for functional reasons such as to control sharply defined edges for better molding and to prevent fraying. In some embodiments, it may be desirable to join, such as by stitching or bonding, the cut textile sections together prior to cutting into pieces, such as to create a long continuous length that can be rolled up for more efficient processing (i.e. coating or molding). In other cases, it may be desirable to join the cut fabric sections together to be cut into shapes larger than the original pieces of used textile, or to impart differing material properties to different regions of the finished article, and/or differing aesthetics in different regions of the finished article.

[0049] In a step 145 a natural fiber is selected and cut to a desired shape. The natural fiber can be in the form of a loose fiber, yarn, non-woven, or woven fabric. The natural fiber can optionally be impregnated with resin and cured before being cut to shape. Suitable natural fibers have a high modulus and high break strength, for example, the natural fibers in Table 1 below.

Table 1 [0050] Table 1 is taken from Frontiers in Materials; Sustainable Fibers as Sustainable and

Renewable Resource for Development of Eco-friendly Composites: A Comprehensive Review, September 2019, Volume 6, Article 226.

[0051] The natural fiber serves to reinforce the molded article and improve the modulus and toughness thereof, whereas the waste textile constituent primarily adds other important attributes like unique and desirable aesthetics. In some embodiments, the combination of natural fibers and waste textiles yields articles that are flexible and leather-like. The waste textile can comprise used clothing such as jeans, pants, shirts, jackets, skirts, dresses, and the like. The waste textile can also be from linen, bed sheets, blankets, or drapery, but can also be waste fabric from industrial applications such as upholstery fabric, industrial coverings, wall coverings, awnings, carpet, cuttings from textile manufacturing, and the like. The waste textile can be from a natural source such as cotton, silk, wool, coir, kenaf, hemp, flax, bamboo, banana, or pineapple, for example. The waste textile can also be made of synthetic fibers produced from petroleum sources such as nylon, polyester, acrylic, polyolefin, polyurethane, nylon, spandex or blends.

[0052] Optionally, the natural fiber can be pre-impregnated with resin and cured into sheets, either by batch or continuous processes. These sheets can also be formed to impart a curvature before being cured. Upon curing, the sheet is cut into sections, for instance, by mechanical or laser methods. Individual planer or non-planer shapes or stacks of shapes may be used. A composite of natural fibers in cured resin is referred to as a “stiffener” herein, and stiffeners can be inserted into the mold along with the waste textile. Advantages of this method include that it offers better resin impregnation, curing, and fiber alignment. Reduced volume shrinkage of the final part is a further possible benefit.

[0053] In step 150 pieces cut from the waste textiles are combined in a mold with a resin and the natural fibers produced in step 145. In an exemplary process, resin is added to the bottom of the mold cavity, a piece cut from waste textile is next added to the mold cavity, the natural fiber is then added to the mold cavity, optionally in the form of a stiffener, and then additional resin is added to the mold cavity. It will be appreciated that multiple layers of pieces cut from waste textiles can be laminated, optionally with alternating additions of natural fibers and the resin. Air bubbles can be squeezed from the mold cavity by assembling the mold or otherwise closing the mold, and then squeezing the mold, or by inserting the mold into a chamber or bag and applying a vacuum. Ports can be added to the mold to both add additional resin and to apply a vacuum to degas and remove air bubbles. Various methods can be used to improve the impregnation the fibers with the resin such as heating, and/or the use of a vacuum.

[0054] In other embodiments the cut piece of waste textile is impregnated with resin before being placed in the mold cavity. For instance, the cut piece of used textile can be submerged in the resin to impregnate the fabric. This is particularly advantageous where the cut pieces of used textile are stitched together into long lengths that can be passed through the resin, molded, and cured in a continuous or semi-continuous manner.

[0055] In step 160 the resin in the mold cavity is cured to form the article. Resin distribution within the mold and relative to the pieces of textiles and natural fibers ensures desired wet-out and impregnation of the fibers of both the textiles and natural fibers as well as the desired cosmetic and functional attributes. The resin can be cured in the mold by applying heat in the range of 45C to 200C, by applying radiation such as UV (Ultraviolet) or IR (infrared) radiation or by applying a combination of heat, and/or UV, and/or IR. If the resin is a thermoplastic, then the molten resin will be combined with the fabric in the mold then cooled to solidify. In further embodiments, the part is partially cured in the mold then removed from the mold prior to being further cured in an oven or by heating with IR. [0056] It is yet another surprising result that the UV curable acrylate formulations disclosed herein can have good curing, wetting, and bonding to the natural fibers and fabrics comprising natural fibers other than used textiles. It is even more surprising that even better performance can be obtained when UV catalyzed and cured systems are combined with thermally catalyzed and cured systems in the same formulation, particularly thermal catalysts of the organic peroxide type. These dual-cure systems appeared to have better adhesion to the natural fibers and a better extent of curing.

[0057] FIG. 2 is a photograph of a 1.25” x 36” strip of denim 200 cut from used denim jeans. The strip of denim 200 and a UV curable resin were placed in a UV transparent mold made of Plexiglass acrylic, exposed to UV radiation while in the mold to cure the resin, and then the article 210 was removed. After trimming the edges of the article 210, a buckle was attached to the end of the article 210 to produce a belt 300 as shown in the photograph of FIG. 3.

[0058] FIG. 4 is a photograph of a purse 400 created according to an exemplary embodiment of the present invention. In this example a Plexiglas acrylic sheet was shaped into an inner mold, and a textured Plexiglas acrylic sheet was shaped into an outer mold in order to create the purse 400. A used Hawaiian style shirt was cut into a shape that would fit into the mold. A UV curable resin was coated onto the surface of the inner mold, the piece of the Hawaiian fabric was placed over the resin and pressed down into it so the resin completely wetted and penetrated the fabric. A layer of resin was then coated on top of the Hawaiian fabric, the outer mold was applied to the resin coated fabric on the inner mold and the inner mold and outer molds we squeezed with pressure to eliminate air bubbles and to get complete wetting of the resin into the fabric and complete wetting on the mold surfaces. The part was then U V cured with an Omnicure 2000 U V curing apparatus. After curing the fabric composite was removed from the mold, and assembled into the complete purse 400 by attaching a strap.

[0059] The present disclosure also provides novel resins suitable for the manufacture of the disclosed articles. In order to limit the impact of global warming it is critical to move away from petroleum-based chemistries to bio-based chemistries that result in products with a lower carbon footprint. For example, sources of bio-based chemistries can be oils from plant, animal, seaweed, or algae sources. Sugars and cellulose can be derived from plants or seaweeds, they could also be derived from fermentation processes or fermented into other chemicals such as polyesters or alcohols, for example.

[0060] Natural oils contain triglycerides based on glycerol and fatty acid chains which contain a degree of unsaturation (double bonds). These triglycerides can be used in resin formulations or chemically modified such as by oxidation to alcohols or epoxides to facilitate alternative reactions. The trigylcerides can be broken down into glycerol and fatty acids to be further chemically modified. For example, glycerol can be reacted with acrylic acid to make a substantially bio-based acrylate monomer. The fatty acids can be chemically modified and reacted with other alcohols to make other bio-based monomers that can be later used in resins. Other bio-based organic diacids and diols can be produced from fermentation of sugars by yeast or bacteria.

[0061] Starch from plants can also be chemically modified into other useful building blocks. For example, starch can be broken down into glucose and used or broken down further into sorbitol and then formed into isosorbide. Isosorbide is a diol that can be used as a bio-based building block to make polyesters, polyurethanes, acrylics, epoxies, or polycarbonates.

[0062] Some of the disadvantages of triglyceride-based monomers is that the resulting polymers have a lower glass transition temperature because the fatty acid chain softens the matrix. Because triglycerides are multi-functional they can also be more brittle. Bisphenol A based polymers usually have excellent hardness, toughness, and chemical resistance. In various embodiments, isosorbide functionalized with epoxy, acrylate, vinyl groups, or isocyanate groups is formulated into the bio-based resin used herein.

[0063] Triglyceride is an ester derived from a glycerol and 3 fatty acids. Triglycerides can be derived from plants, animals, and algae. Copolymers of isosorbide and triglycerides can be synthesized by first oxidizing the double bonds in the triglyceride to the alcohol then reacting the alcohol groups, including the isosorbide, with methacrylate anhydride. While isosorbide increases the glass transition temperature (Tg) and modulus of the system, one of the drawbacks is that isosorbide also substantially decreases the break strain, which also limits the toughness of the system.

[0064] Fatty acids contain an aliphatic chain with a carboxylic acid group on one end, where the aliphatic chain can be unsaturated (contains some double bonds) or saturated (does not contain double bonds). The aliphatic chain length can range from a few carbons to 22 carbons or more. It is believed that an unsaturated fatty acid can be reacted with isosorbide to create unsaturated polyester described in the reaction shown in FIG. 5.

[0065] The theoretical advantages of this isosorbide diester include that it can he substantially greater than 80% to essentially 100% bio-based, that it is stable but contains functional groups for later cross-linking or polymer grafting reactions, that it can be designed to be a liquid at room temperature for ease of processing, and it can impart flexibility into the fully formulated resin system as compared to functionalized isosorbide reported in the literature. A wide range of properties can be imparted depending on the type of fatty acid chosen. Examples of unsaturated fatty acids that can be used in this invention include, but are not limited to, oleic acid, linoleic acid, stearidonic acid, nervonic acid, palmitoleic acid, and arachidonic acid. Optionally, the double bonds in the unsaturated fatty acid can be oxidized to an epoxy or alcohol to facilitate alternative cross-linking or polymer grafting reactions.

Examples

[0066] Sunglasses were produced by separately molding in separate molds, a left temple arm, a right temple arm, and a front frame. FIG. 6 shows a UV transparent left temple arm mold, a piece of a waste textile and a resin-impregnated piece of waste textile, and a natural fiber stiffener made from hemp fiber, in this example. In FIG. 6, the piece below the mold is the stiffener, the piece in the middle is the resin-impregnated piece of waste textile, and the bottom piece is simply the piece of waste textile. Not shown in FIG. 6 is a metal insert used to reinforce the hinge section. FIG. 7 shows exemplary molded left and right temple arm examples. The reinforcing metal inserts can be seen in the photograph in FIG. 7. FIG. 8 shows a front frame mold including both fill and vacuum ports. FIG. 9 shows examples of cut waste textile and molded front frame. FIG. 10 shows exemplary front frames molded with the mold of FIG. 8, with tinted lenses attached to the front frames. FIG. 11 shows an exemplary finished pair of sunglasses. The several molded parts are described further below. [0067] The temple arms in FIG. 7 were made by preparing a resin by mixing 30 grams of Ebecryl 5850 with 1 gram of Irgacure 819 and 0.5 grams of Luperox EP, the mixture was heated to 40-48C with stirring until the Irgacure and Luperox dissolved, then 22 grams of Ebecryl 4491 was added to the mixture and stirred until it became a transparent solution. Hemp yam from Hemp Basics (4501 - Single Strand Bleached Hemp "Super Fine Lace Weight" Yam) was wrapped around a sheet of *4” thick PMMA sheet. The resin was then coated on top of the hemp yam then a top sheet of *4” PMMA was applied with pressure to infuse the resin into the hemp yarn and remove the air bubbles. Both sides of the hemp/resin/PMMA sheet were cured with UV light exposure from an Omnicure Series 2000 light source. The PMMA sheets were removed and the hemp-resin laminate was cut into the temple arm shape using a razor blade or a laser (see the first piece below the mold in FIG. 6). A sheet of a waste textile was twice cut into the shape of a temple arm using a razor blade or a laser (see the bottom two pieces below the mold in FIG. 6), where one is impregnated with resin while the other was not. The two pieces are presented as alternatives, only one was used to make the finished product.

[0068] The resin was added to the mold shown in FIG. 6 as a thin, uniform layer. The hemp-resin stiffener was added to the mold, then another thin layer of resin was added to the mold over the hemp-resin stiffener. One of the two alternate waste textile pieces was added to the mold and more resin was added to completely fill the mold. The top was added to the mold and the mold was clamped shut. Excess resin was purged through the mold with a syringe through a hole in the hinge section of the mold until all of the air was removed from the mold. The mold was illuminated with UV from the Omnicure 2000 light source from all sides of the mold. The mold was then placed into an oven at 80C for 2 hours. The mold was removed from the oven and allowed to cool to room temperature and the finished temple arm was removed from the mold.

[0069] The sunglass front frame was made in a similar manner using the same resin formulation. A sheet of waste textile was cut into the shape of a front frame using a razor blade or a laser. The resin was added to the mold shown in FIG. 8 as a thin uniform layer, and the cut piece of the waste textile was added to the mold. In this example a natural fiber stiffener was also added to the mold, but it should be understood that the stiffener is optional and could be replaced with a woven natural fiber fabric cut to the appropriate shape. More resin was added to completely fill the mold and then the top was added and the mold was clamped shut. Excess resin was purged through the mold with a syringe through a port until all of the air was removed from the mold, and optionally vacuum was applied to further remove air bubbles and moisture. The mold was exposed with UV from the Omnicure 2000 light source from all sides of the mold. The mold was then placed into an oven at 80C for 2 hours, after which the mold was removed from the oven and allowed to cool to room temperature, and the finished part was then removed from the mold.

[0070] In another embodiment, the front frame and/or the temple arms in the prior example can be produced by optionally shredding the waste textile instead of cutting the fabric to a specific shape. Here, resin is added to the mold, then shredded waste textile is carefully placed into the mold, then more resin is added, and the part is completed as described above. FIG. 10 shows examples of front frames including tinted lenses produced from shredded waste textile (top) and cut waste textile (bottom). One of the front frames from FIG. 10 and temple arms from FIG. 7 are assembled with screws and bolts into a final pair of sunglasses shown in FIG. 11.

[0071] FIG. 12 illustrates further embodiments of articles of manufacture that can be fabricated according to embodiments of the invention. FIG. 12 shows a mold and a decorative tile molded therein according to the same steps described above. In this example, waste textile was cut into squares sized to fit the mold.

[0072] The embodiments discussed herein are illustrative of the present invention. As these embodiments of the present invention are described with reference to illustrations, various modifications or adaptations of the methods and or specific structures described may become apparent to those skilled in the art. All such modifications, adaptations, or variations that rely upon the teachings of the present invention, and through which these teachings have advanced the art, are considered to be within the spirit and scope of the present invention. Hence, these descriptions and drawings should not be considered in a limiting sense, as it is understood that the present invention is in no way limited to only the embodiments illustrated.

Claims

CLAIMS What is claimed is:

1. A method of forming an article of manufacture, comprising: cutting a waste textile into pieces; combining a piece of the waste-textile with natural fibers and a resin in a mold; and curing the resin to form the article.

2. The method of claim 1 wherein the natural fibers are disposed as a layer within the mold.

3. The method of claims 1 or 2 wherein the resin comprises isosorbide functionalized with an epoxy, an acrylate, a vinyl group, or an isocyanate group.

4. The method of claims 1, 2, or 3 wherein the resin comprises isosorbide functionalized with an unsaturated fatty acid.

5. The method of claims 1-3 or 4 wherein the resin comprises a mixture of thermoplastic and thermosetting resins.

6. The method of claim 5 wherein the thermosetting resin comprises an acrylic.

7. The method of claims 1-5 or 6 wherein the waste textile comprises a used textile.

8. The method of claims 1-6 or 7 wherein the waste textile comprises a scrap textile.

9. The method of claims 1-7 or 8 wherein cutting the waste textile comprises shearing, shredding, or laser cutting the waste textile.

10. The method of claims 1-8 or 9 further comprising forming the natural fibers into a stiffener and the step of combining the piece of the waste-textile with the natural fibers and the resin in the mold includes placing the stiffener in the mold.

11. The method of claim 1-9 or 10 wherein the mold comprises a UV transparent material and curing the resin includes exposing the resin to UV radiation through the mold.

12. The method of claim 11 wherein curing the resin further includes heating the article to complete the cure of the resin.

13. The method of claims 1-11 or 12 further comprising washing and drying the waste textile before cutting the waste textile.

14. The method of claims 1 -12 or 13 wherein combining the piece of the waste textile with the resin in the mold includes impregnating the piece with the resin before placing the piece in the mold.

15. The method of claims 1-13 or 14 wherein combining the piece of the waste textile with the natural fiber and the resin in the mold includes placing the resin in the mold, then placing the piece in the mold, and then placing more resin in the mold.

16. The method of claims 1-14 or 15 wherein the resin is a thermosetting or thermoplastic polymer.

17. The method of claims 1-15 or 16 wherein the resin includes a photoinitiator.

18. The method of claims 1-16 or 17 wherein the resin includes a thermal initiator.

19. The method of claims 1-17 or 18 wherein the thermal initiator is of an organic peroxide.

20. The method of claims 1-18 or 19 further comprising obtaining mixed used textiles including the waste textile, and sorting the mixed used textiles.

21. The method of claim 20 further comprising measuring the UV transmissivity of the used textiles.

22. The method of claim 20 further comprising washing and drying the used textiles.

23. The method of claims 1 -21 or 22 further comprising stitching the piece of the waste textile before combining the piece of the waste textile with the natural fibers and the resin in the mold.

24. The method of claims 1-22 or 23 further comprising heating the piece of the waste textile with the natural f ibers and the resin in the mold.

25. The method of claims 1-23 or 24 wherein combining the piece of the waste textile with the natural fibers and the resin in the mold further comprises combining a second piece of a textile in the mold with the piece of waste textile and the natural fibers and the resin, such that the piece of the waste textile and the second piece of textile are layered.

26. The method of claim 25 wherein the second piece of textile is of a glass, carbon fiber, or synthetic fiber textile.

27. An article of manufacture comprising: a composite of a piece of a waste textile and natural fibers within a cured resin.

28. A method of forming a resin comprising: reacting an unsaturated fatty acid with isosorbide to create an unsaturated polyester resin.