Patent Application
20150282544
The present invention relates to a material for apparel with a very low weight, improved tensile strength, and breathability.
For many years, there has been a need to develop lighter and stronger materials to improve quality, safety, and efficiency in a vast array of industries, including but not limited to aerospace, automotive, marine, apparel, sporting goods, fiber optics, industrial safety, military and law enforcement, and electronics.
Since the 1950's, there have been numerous breakthroughs in the development of high performance fibers having many times the strength of steel at a fraction of the weight. For many years, high performance fibers have been used in woven and non-woven arrangements to form multilayered composites and laminated structures. Examples of such high performance fibers include but are not limited to polyester fibers (such as the products sold under the trade name Dacron®), nylon fibers, aramid fibers (such as the products sold under the trade names Kevlar®, Techora®, and Twaron®), carbon fibers, ultra high molecular weight polyethylene (“UHMWPE”) (such as products sold under the trade names Ceran®, Dyneema®, and Spectra®), liquid crystal polymers (“LCP”) (such as products sold under the trade name Vectran®) and (poly (p-phenylene-2, 6-benzobisoxazole)) (“PBO”) (such as products sold under the trade name Zylon®), and polyethylene naphthalate PEN fibers (such as products sold under the trade name Pentex®).
For example, WO 2012/018959 describes the problems with using the high performance fibers in a woven configuration. Specifically, the weaving processes induce crimp in the fibers, which cause stress concentrations and wear points that significantly reduce the strength and long term performance of the fabric.
U.S. Pat. No. 5,333,568 also describes the crimping problem with woven configurations, while describing a reinforced nonwoven laminate that utilizes a reinforcing sheet of unidirectionally extruded monofilaments in which the reinforcing sheet or sheets form one or more uni-tapes laminated to outer layers of polyester film. The monofilaments are uniformly embedded in the uni-tape via an elastomeric polymer matrix. The resulting material has very low weight, high shear strength with increased rip resistance, and is waterproof (such as the product sold under the trade name Cuben fibers or CTF3™). However, because the elastomeric polymer matrix melts uniformly to form the uni-tape around the monofilaments, the material does not permit any air or moisture to pass through and therefore has no breathability.
U.S. Pat. No. 4,194,041 describes a waterproof and breathable laminate formed of an inner hydrophilic layer, which is a copolymer of tetrafluoroethylene and a monomer, and an outer layer, which is hydrophobic, porous, and permeable to gases. In short, the inner layer has pore sizes that are 20,000 times smaller than the size of a water droplet, but 700 times larger than a water vapor molecule. As a result, the inner layer is completely waterproof from the outside, while allowing perspiration to escape from the inside. In use, the inner layer is typically formed of polytetrafluoroethylene (“PTFE”) and the outer layer is typically nylon or polyester for strength.
However, because the unprotected inner PTFE layer quickly became clogged with oil and other contaminants when the unprotected inner PTFE layer was placed in contact with a person, a very thin polyurethane (“PU”) film was added in layer versions to protect the PTFE layer from contamination. Because the PU film is monolithic (i.e., solid), oils and other contaminants cannot pass through the PU film into the PTFE layer. In order to allow water to pass through the PU film, hydrophilic materials, such as polyethylene oxide, were incorporated into the PU film. The water is attracted to the inner side of the PU film, and gradually seeps through the PU film via diffusion due to the variance in concentration (or differential pressure) between the two sides of the PU film. Once the water reaches the other side of the PU film, the molecules evaporate and escape through the PTFE membrane as a gas. The problem is that a minimum differential pressure is required before the fabric begins to remove water.
U.S. Pat. No. 7,825,046 describes a waterproof and breathable laminate formed of a porous outer layer of fabric laminated to an inner microporous membrane of expanded polytetrafluoroethylene (“ePTFE”) that has been treated with an oil resistant treatment material (such as the product sold under the trade name eVENT®). Because the ePTFE membrane is protected from contaminants via the treatment material, an inner PU film is not required to protect the ePTFE membrane from contaminants. As a result, water vapor can pass directly through the ePTFE membrane without the need for a minimum differential pressure. The drawback of this membrane is the reduced durability.
WO 2011/163643 describes an attempt to improve the breathability of the nonwoven laminate described in U.S. Pat. No. 5,333,568 through various combinations with the PTFE membrane described U.S. Pat. No. 7,825,046. In particular, the nonwoven laminate is adjusted by either reducing the amount of elastomeric polymer matrix so that there is a sufficient amount to adhere to other layers, but not sufficient to form a continuous layer surrounding the monofilaments or by substituting a hydrophilic polymer in place of the elastomeric polymer matrix or using a hydrophilic polymer (such as polyurethane (“PU”)) to fill in the gaps left by the elastomeric polymer matrix. While the change in concentration and/or formulation of the matrix may have improved the breathability of the nonwoven laminate, the bond between the layers is reduced and thus more prone to delamination problems.
Thus, it is desirable to provide a nonwoven multilayered composite and/or laminated structure, wherein each layer comprises unidirectional high performance fibers, which provides a very low weight material with high tensile strength, good breathability, and good bonding between the layers to prevent delamination after repeated use.
The terms “invention,” “the invention,” “this invention” and “the present invention” used in this patent are intended to refer broadly to all of the subject matter of this patent and the patent claims below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the patent claims below. Embodiments of the invention covered by this patent are defined by the claims below, not this summary. This summary is a high-level overview of various aspects of the invention and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification of this patent, any or all drawings and each claim.
According to certain embodiments of the present invention, multilayered breathable and waterproof material comprises at least two nonwoven fiber layers, each fiber layer comprising a plurality of unidirectionally oriented fibers coated with a matrix material, wherein the fibers in a first one of the at least two nonwoven fiber layers form an angle of approximately 90° with respect to the fibers in another one of the at least two nonwoven fiber layers, an outer layer adhered to a side of one of the at least two nonwoven fiber layers, and a polyurethane inner membrane adhered to another side of the at least two nonwoven fiber layers, wherein at least the inner membrane is embossed.
In some embodiments, the fibers in a first one of the at least two nonwoven fiber layers may form an angle in a range of 80°-100° with respect to the fibers in another one of the at least two nonwoven fiber layers.
In some embodiments, a plurality of gaps are formed between the fibers in each nonwoven fiber layer. A second hydrophilic matrix material may be applied fill in the plurality of gaps between the fibers and bond the nonwoven fiber layers, the outer layer, and the inner membrane.
In certain embodiments, the second hydrophilic matrix material is polyurethane. In some embodiments, the matrix material is polyurethane. In certain embodiments, the outer layer is formed of nylon, polyester, or a combination thereof.
According to certain embodiments, the inner membrane has a thickness of approximately 11 microns. In some embodiments, material has a breathability greater than approximately 20,000 grams/m2/24 hr B1 JIS.
The fibers may be formed of ultra high molecular weight polyethylene, other polyethylenes, polyester, nylon, Basalt, aramid, carbon, polymer/carbon composites, liquid crystal polymers, or high performance films.
In certain embodiments, at least the inner membrane is embossed with a stamp emboss having a crowned surface.
According to certain embodiments of the present invention, a multilayered breathable and waterproof material comprises at least two nonwoven fiber layers, each fiber layer comprising a plurality of unidirectionally oriented fibers embedded within a hydrophilic matrix material, wherein the fibers in a first one of the at least two nonwoven fiber layers form an angle of approximately 90° with respect to the fibers in another one of the at least two nonwoven fiber layers, a outer layer adhered to a side of one of the at least two nonwoven fiber layers, and a polyurethane inner membrane adhered to another side of the at least two nonwoven fiber layers.
In some embodiments, the fibers in a first one of the at least two nonwoven fiber layers may form an angle in a range of 80°-100° with respect to the fibers in another one of the at least two nonwoven fiber layers.
In some embodiments, the hydrophilic matrix material is polyurethane. In certain embodiments, the outer layer is formed of nylon, polyester, or a combination thereof.
According to certain embodiments, the inner membrane has a thickness of approximately 11 microns. In some embodiments, the material has a breathability greater than approximately 20,000 grams/m2/24 hr B1 JIS.
The fibers may be formed of ultra high molecular weight polyethylene, other polyethylenes, polyester, nylon, Basalt, aramid, carbon, polymer/carbon composites, liquid crystal polymers, or high performance films.
In some embodiments, an insulating inner layer is coupled to the inner membrane.
According to certain embodiments of the present invention, a multilayered breathable and waterproof material comprises at least two nonwoven fiber layers, each fiber layer comprising a plurality of unidirectionally oriented fibers coated with a hydrophilic matrix material, wherein the fibers in a first one of the at least two nonwoven fiber layers form an angle of approximately 90° with respect to the fibers in another one of the at least two nonwoven fiber layers, an outer layer adhered to a side of one of the at least two nonwoven fiber layers, and a polyurethane inner membrane adhered to another side of the at least two nonwoven fiber layers, wherein at least the inner membrane is embossed, wherein the material has a breathability of greater than 20,000 grams/m2/24 hr B1 JIS.
In some embodiments, the fibers in a first one of the at least two nonwoven fiber layers may form an angle in a range of 80°-100° with respect to the fibers in another one of the at least two nonwoven fiber layers.
In some embodiments, the hydrophilic matrix material is polyurethane. In certain embodiments, the outer layer is formed of nylon, polyester, or a combination thereof.
According to certain embodiments, the inner membrane has a thickness of approximately 11 microns.
The fibers may be formed of ultra high molecular weight polyethylene, other polyethylenes, polyester, nylon, Basalt, aramid, carbon, polymer/carbon composites, liquid crystal polymers, or high performance films.
In the following detailed description, embodiments of the invention are described referring to the following figures:
The subject matter of embodiments of the present invention is described here with specificity to meet statutory requirements, but this description is not necessarily intended to limit the scope of the claims. The claimed subject matter may be embodied in other ways, may include different elements or steps, and may be used in conjunction with other existing or future technologies. This description should not be interpreted as implying any particular order or arrangement among or between various steps or elements except when the order of individual steps or arrangement of elements is explicitly described.
Embodiments of the present invention provide textile materials having low weight, high tensile strength, good breathability, and good bonding between the layers to prevent delamination after repeated use. While the textile materials are discussed having two fiber layers, an inner membrane, and an outer fabric layer, they are by no means so limited. Rather, embodiments of the textile materials may include any suitable number of fiber and/or other layers as needed or desired to achieve the desired properties.
While the embodiments shown in
The outer layer 12 is included to improve the overall look and feel of the material 10, as well as providing the ability to stitch the material 10. The outer layer 12 also requires good abrasion resistance to provide durability to the material 10.
The outer layer 12 further requires sufficient air permeability with a value greater than 1 CFM in certain embodiments, which will vary according to the size of the spaces between the yarn. Thus, thickness, weight, density of weave and finishing of the material all play a role in the air permeability of the outer layer 12.
The outer layer 12 also requires good hydrophobic properties to force diffused moisture 20 to evaporate from the outer surface of the material 10. The hydrophobic properties also work to prevent moisture 22 from entering the material 10 from outside. In certain instances, an additional coating, such as fluorocarbon C6, may be added on an outer surface 24 of the outer layer 12 to improve the water repelling properties.
Suitable materials for the outer layer 12 include but are not limited to nylon, polyester, a combination of nylon and polyester, or other suitable materials. Nylon provides good abrasion resistance and some hydrophobic properties. Polyester also provides good hydrophobic properties, but provides less abrasion resistance. Thus, a combination of nylon and polyester may provide an outer layer 12 with both enhanced hydrophobic and abrasion resistance properties.
In some embodiments, fibers 26 in the first and second fiber layers 14, 16 are formed of UHMWPE. UHMWPE fibers can be up to 15 times stronger than steel, but up to 40% lighter than materials like aramids. UHMWPE fibers have very little elasticity and are very difficult to break. Other fiber materials may include polyester fibers (such as the products sold under the trade name Dacron®), nylon fibers, natural fibers such as Basalt, aramid fibers (such as the products sold under the trade names Kevlar®, Techora®, and Twaron®), carbon fibers, high performance films (such as polyethylene naphthalate (“PEN”) films and products sold under the trade name Mylar®), polymer/carbon composites (such as single-wall carbon nanotubes (“SWCNT”) or graphene) and may include but is not limited to combinations of polyvinylalcohol/carbon and/or polyacrylonitrile/carbon, liquid crystal polymers (“LCP”) (such as products sold under the trade name Vectran®) and (poly (p-phenylene-2,6-benzobisoxazole)) (“PBO”) (such as products sold under the trade name Zylon®), polyethylenes (such as products sold under the trade names Ceran®, Dyneema®, and Spectra®) and PEN fibers (such as products sold under the trade name Pentex®), or other suitable materials. The first and second fiber layers 14, 16 may be formed of the same or different materials to achieve the desired properties.
In certain embodiments, the fibers 26 have a thickness of less than 1 denier. The shear strength of the material 10 is influenced by the density or number of crossover points between the fiber layers 14, 16. Higher crossover densities may be achieved by smaller diameter fibers and/or increasing the number of threads in a given area. However, a person of ordinary skill in the relevant art will understand that different fiber thicknesses and concentrations may be used in the various fiber layers 14, 16 to achieve the desired properties.
Each fiber layer 14, 16 may be formed by coating each fiber 26 with the matrix material and pulling the coated fibers 26 in parallel through a die so that the fibers are laterally married to form a unidirectional tape. Additional details of the general formation of each fiber layer 14, 16 are described in U.S. Pat. No. 5,333,568 and U.S. Pat. No. 5,470,632, the contents of each of which is incorporated herein by reference.
In certain embodiments, the matrix material may be a non-hydrophilic material, which is applied in sufficiently thin concentrations to allow gaps to form between the fibers 26. These gaps may remain open to allow diffused moisture to pass through to the outer layer 12. In other embodiments, the gaps may be filled by a hydrophilic adhesive, such as PU or PES. In yet other embodiments, the entire matrix material may be a hydrophilic adhesive. Additional details of the formation of each fiber layer 14, 16 with breathable properties are described in WO 2011/163643, the contents of which is incorporated herein by reference.
In the embodiments where there are no gaps between the fibers 26, the matrix material (which either replaces the non-hydrophilic matrix material or fills in the gaps left by the non-hydrophilic matrix material) must have a sufficient hydrophilic properties to allow water to continue to diffuse through the material 10 from the inner membrane 18 to the outer layer 12, so as not to negatively impact the breathability of the material 10. In certain embodiments, the matrix material may be formed of the same material as the inner membrane 18 or may be formed of different materials. In some embodiments, to further improve breathability, the inner membrane 18 may be omitted so that the inner surface of the fiber layer 16 forms the inner surface of the material 10.
In the embodiments where the matrix material is configured to leave gaps between the fibers 26, a porous film of matrix material may be used or the matrix material may be applied in a dotted pattern. The matrix material may also be hydrophilic in these embodiments to further pull the moisture through the fiber layers 14, 16 toward the outer layer 12. In other embodiments, the matrix material may be hydrophobic to force the water to evaporate from the fiber layers 14, 16 even before the water reaches the outer layer 12.
In the embodiments illustrated in
In the embodiments that comprise more than two fiber layers, the three fiber layers 14, 16, 17 are arranged in a regular pattern in the range of (−60°/0°/60°). In other words, in the examples illustrated in
In certain embodiments, the arrangement of at least three fiber layers in the material 10 may range anywhere from (−25° to −65°)/0°/(+25° to +65°), may range anywhere from (−30° to −60°)/0°/(+30° to +60°), may range anywhere from (−35° to −55°)/0°/(+35° to +55°), or may range anywhere from (−40° to −50°)/0°/(+40° to +50°). Furthermore, the orientation of the fiber layers within these ranges may be symmetrical, such as the (−60°/0°/60°) embodiments illustrated in
According to certain embodiments, the inner membrane 18 is formed of a hydrophilic nonporous material. Suitable materials may include polyurethane (“PU”), polyester, polysulfone (“PES”), or other suitable materials. Moisture 20 is attracted to an inner surface 28 of the inner membrane 18, and gradually seeps through the inner membrane 18 via diffusion due to a variance in concentration (or differential pressure) between the two sides of the inner membrane 18. A certain minimum thickness of the inner membrane 18 is required to achieve an overall long term durability and sufficiently good bonding between the layers to prevent delamination after repeated use. However, a thinner inner membrane 18 is better for breathability. In some embodiments, a thickness of approximately 11 μm (microns) pre-lamination is generally preferred.
As illustrated in
In certain embodiments, as illustrated in
Certain exemplary embodiments are set forth below:
Required standards of physical characteristics for the material 10 are as follows:
Breathability: ≧20,000 gram/m2/24 hr B1 JIS
Hydrostatic head: ≧15,000 mm/24 hr ISO 811 (preferably 20,000 mm/24 hr ISO 811)
Tensile Strength: ≧400 N (preferably 400-500 N)
Tear Strength: >2× stronger than known 50 D-70 D 3 L waterproof materials
External abrasion resistance: 50 cycles (400 grade grit paper)
Weight below 100, preferred 50-80 g/m2
Each of the examples 1-2 had translucent appearance, as opposed to a clear/transparent look, and were very light and within the preferred weight range. Examples 1-2, using a 10 D face fabric, showed a good level of translucency, but the 10 D materials failed abrasion resistance requirements. Specifically, examples 1 and 2 had difficulties with bonding the polyester membrane to the fiber layers, thus demonstrating poor bonding between the layers.
As a result, a 20 D face fabric was used for all subsequent trials.
Example 3 demonstrated a weight of 68 g/m2. Example 3 was also more durable to washing and abrasion than Examples 1-2. The material meets the criteria.
Example 4 has positive performance. Specifically, in certain embodiments, example 4 demonstrates a weight of approximately 67 g/m2, a breathability of ≧18,000 gram/m2/24 hr B1 JIS, a hydrostatic head of ≧20,00 mm/24 hr ISO 811, and 2-3% Shrinkage.
To prevent shrinkage, a non continuous stamp emboss was added to the internal membrane 18 to stabilize wash shrinkage and improve the feeling of internal dryness by reducing surface contact area. The scale of the emboss stamp is one that requires multiple pressing across the width and length of the internal membrane 18 material in a non continuous process.
In some embodiments, a crowned surface may be used with the stamp emboss so that a central region of the stamp emboss leaves a deeper embossed design on the material 10 than edges of the stamp emboss. As a result, it is less critical to ensure perfect alignment between each press to avoid overlapping edges that are pressed more than once.
Other embodiments may include roller embossing in a continuous process across the full width of the internal membrane 18 material. The embossing pressure, scale, and pattern have been optimized to reduce any negative effect on non-shrinkage related performance characteristics (i.e., tensile and tear strength). Embossing could be applied in an continuous lamination process or in an continuous post process.
Different arrangements of the components depicted in the drawings or described above, as well as components and steps not shown or described are possible. Similarly, some features and sub-combinations are useful and may be employed without reference to other features and sub-combinations. Embodiments of the invention have been described for illustrative and not restrictive purposes, and alternative embodiments will become apparent to readers of this patent. Accordingly, the present invention is not limited to the embodiments described above or depicted in the drawings, and various embodiments and modifications may be made without departing from the scope of the claims below.
