PARACHUTE BUFFER MATERIAL
In one aspect, parachute buffer materials are described herein. In some embodiments, parachute buffer materials described herein comprise a fabric formed from a plurality of fibers and a coating disposed on at least one outer surface of the fabric. The fibers have an inner component formed from a thermoplastic material and an outer component formed from a non-thermoplastic material. In some cases, the fabric is a woven fabric. Additionally, the coating can comprise or contain a silicone along with, or without, other functional components. Moreover, materials described herein can be used to form various structures for parachute buffering applications, and the coatings of materials described herein can enhance the materials' buffering performance.
This application claims priority pursuant to 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 62/174,192, filed on Jun. 11, 2015, and to U.S. Provisional Patent Application Ser. No. 62/277,610, filed on Jan. 12, 2016, each of which is hereby incorporated by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENTThe invention was made under a contract with an agency of the U.S. Government. The name of the U.S. Government agency and Government contract number are: Department of the Army, Contract number W911QY-12-P-0343. The Government has certain rights in the invention.
FIELDThe present invention relates to parachute buffer materials and, in particular, to fabrics and/or surface treatments for such materials.
BACKGROUNDIn the development of the modern parachute, there have been two major shifts. The first such shift came in the early 1940s, when the United States ceased using silk and instead began to make parachutes from nylon. The second major shift came in the 1950s, when parachutes began to be used as a mechanism for the delivery of larger, heavier materials dropped from airplanes traveling at much higher speeds. It was discovered during the second major shift that if a nylon parachute canopy contacted another nylon surface, such as the outer nylon parachute bag, the resulting high speeds at the contact interface caused melt damage to the parachute canopy. In order to address this issue, “buffering” materials were developed that were used to construct “buffer” structures designed to provide protective surfaces between the nylon parachute canopy and other nylons surfaces during the deployment process. These structures included the primary buffering structure (the “parachute deployment bag” or “parachute buffer bag”) along with various other cords and small fabric structures. All of these structures were designed to minimize the potential for damaging nylon-on-nylon contact during the deployment process. The original parachute buffer structures were based on cotton. Such cotton-based structures (cotton parachute buffer bags, cotton cords, and related structures) provide the required separation of nylon surfaces, eliminating contact damage during the parachute deployment process.
Since the shift to the use of buffer bags and related buffer structures in the 1950s, the fabrics used to produce buffer bags and other fabric structures have been formed from a cotton “airplane cloth,” originally designed to cover the wings and other surfaces of airplanes. In order to obtain the desired properties for use in buffer structures, airplane cloth has traditionally been made or formed from 100% long staple cotton fibers. Unfortunately, such material suffers from several disadvantages or deficiencies. For example, obtaining and processing the high quality, long staple cotton necessary to provide the high strength cotton fabric is often difficult. Therefore, lower strength cotton fabrics have been substituted for the higher strength cotton fabrics, resulting in buffer bags with a reduced service life. Further, bags formed from 100% cotton fabric are often unusable after as little as one washing cycle due to the shrinkage-prone nature of the fabric. Thus, there is a need for improved buffer fabric/material that can be used in the preparation of parachute buffer bags and related buffer fabric structures. One objective of the present disclosure is to provide a new parachute buffer material that addresses one or more deficiencies of previous buffer materials.
SUMMARYIn one aspect, parachute buffer materials are described herein which, in some embodiments, can provide one or more advantages compared to other parachute buffer materials. For instance, in some cases, a parachute buffer material or fabric described herein can provide increased tear strength and/or increased ball burst strength as compared to prior parachute buffer materials or fabrics. In addition, in some instances, a parachute buffer material or fabric described herein can provide increased shrinkage resistance and/or increased air permeability as compared to prior parachute buffer materials or fabrics. Further, parachute buffer materials or fabrics described herein may also provide a lower cost to produce and/or may be formed from less expensive materials relative to prior parachute buffer materials or fabrics. Parachute buffer materials or fabrics described herein may also have a longer useful service life, including after multiple washing cycles.
In some instances, a parachute buffer material described herein comprises a fabric formed from a plurality of fibers and a coating disposed on at least one outer surface of the fabric. The fibers have an inner component formed from a thermoplastic material and an outer component formed from a non-thermoplastic material, and the coating comprises silicone. In some embodiments, the inner component of the fibers is formed from a material selected from the group consisting of a nylon, a polyester, a polypropylene, and a polyethylene. Further, in some cases, the outer component of the fibers is formed from a material selected from the group consisting of cotton, linen, rayon, acrylic, and an aramid. In some instances, each of the fibers comprises between about 10 wt.-% and about 70 wt.-% inner component, based on the total weight of the fiber. Additionally, in some embodiments, each of the fibers comprises between about 20 wt.-% and about 80 wt.-% outer component, based on the total weight of the fiber. The fabric, in some cases, can be woven. For example, in some embodiments, the fabric is a woven fabric formed using a plain weave. Additionally, in certain instances, the coating can further comprise or include additional materials or components, such as a polymeric material, an anti-wicking agent, and/or an antimicrobial agent.
These and other embodiments are described in more detail in the detailed description which follows.
Embodiments described herein can be understood more readily by reference to the following detailed description, examples, and drawings. Elements, apparatus, and methods described herein, however, are not limited to the specific embodiments presented in the detailed description, examples, and drawings. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptations will be readily apparent to those of skill in the art without departing from the spirit and scope of the invention.
In addition, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein. For example, a stated range of “1.0 to 10.0” should be considered to include any and all subranges beginning with a minimum value of 1.0 or more and ending with a maximum value of 10.0 or less, e.g., 1.0 to 5.3, or 4.7 to 10.0, or 3.6 to 7.9.
All ranges disclosed herein are also to be considered to include the end points of the range, unless expressly stated otherwise. For example, a range of “between 5 and 10” should generally be considered to include the end points 5 and 10.
In one aspect, parachute buffer materials are described herein. Parachute buffer materials can be used to form part or all of any structure consistent with the objectives of the present invention. For example, in some embodiments, parachute buffer materials described herein can form part or all of a parachute buffer bag. Parachute buffer materials described herein may also be used to form part or all of a cord or other small fabric structure used as a parachute buffer material. In some instances, a parachute buffer material comprises a fabric formed from a plurality of fibers, the fibers having an inner component formed from a thermoplastic material and an outer component formed from a non-thermoplastic material. A “thermoplastic material,” for reference purposes herein, is a plastic material, such as a polymer, that becomes pliable or moldable above a specific temperature and solidifies upon cooling. For example, a thermoplastic material can be selected from the group consisting of a polyamide, a polyester, or a polyolefin. In some cases, an inner component can comprise, consist or consist essentially of nylon 6,6, nylon 6, polyethylene terephthalate (“PET”), poly-1,3-propylene terephthalate (“PPT”), poly-1,4-butylene terephthalate (“PBT”) and/or combinations thereof. A “non-thermoplastic material,” for reference purposes herein, can be any other naturally occurring or synthetic material that is not a thermoplastic material. For example, in some embodiments, a non-thermoplastic material can be selected from the group consisting of cotton, linen, rayon, acrylic, and an aramid. Examples of aramids usable as an outer component are KEVLAR® and NOMEX® (commercially available from E. I. du Pont de Nemours and Company).
The foregoing structure comprising an inner component comprising or formed from a thermoplastic material, and an outer component comprising or formed from a non-thermoplastic material exemplifies a preferred embodiment of a fiber usable in fabrics for parachute buffer materials described herein. However, other structures are also contemplated. For example, in some embodiments, fabrics can comprise or be formed from fibers comprising, consisting, or consisting essentially of an inner component comprising a non-thermoplastic material. Any non-thermoplastic material can be used. For example, a non-thermoplastic material usable as an inner component, in some embodiments, can be selected from the group consisting of cotton, linen, rayon, acrylic, and an aramid. In certain embodiments, a non-thermoplastic inner component can be selected having relatively high tensile strength as compared to other fiber materials.
Inner components and/or outer components of the fibers to be used in the preparation of fabrics for use in the construction of parachute buffer materials described herein can have any architecture, orientation or configuration not inconsistent with the objectives of the present invention. For example, in some embodiments, the inner component is a monofilament thread. In certain other embodiments, the inner component comprises or is formed from a plurality of monofilament threads. In such embodiments, one or more of the monofilament threads can be formed from a first thermoplastic material and one or more of the monofilament threads can be formed from a second thermoplastic material differing from the first thermoplastic material. In other cases, all or substantially all of the monofilament threads in such a configuration can be formed from the same or substantially the same thermoplastic material. Moreover, in some cases, the inner component can be a bicomponent or conjugate fiber formed from a plurality of thermoplastic materials.
The inner component of a fiber described herein can form any proportion of the total weight of the fiber not inconsistent with the objectives of the present invention. In some embodiments, for instance, the fibers of a fabric described herein comprise between about 10 wt.-% and about 70 wt.-% inner component, based on the total weight of the fiber. In some cases, the fibers of a fabric described herein comprise between about 10 wt.-% and about 60 wt.-% inner component, or between about 10 wt.-% and about 50 wt.-% inner component. In some embodiments, the fibers can comprise between about 20 wt.-% and about 70 wt.-% inner component, between about 20 wt.-% and about 60 wt.-% inner component, or between about 30 wt.-% and about 50 wt.-% inner component, based on the total weight of the fiber.
The outer component of a fiber can be disposed around the inner component of the fiber in any manner not inconsistent with the objectives of the present invention. For example, in some embodiments, the outer component can be spun around or wrapped around a longitudinal axis of the inner component to form a core spun yarn. For example, in one embodiment, a monofilament thread formed from a thermoplastic material is used as a core, and one or more threads or fibers of a non-thermoplastic material are wound, spun or wrapped around the inner component to form an outer component. In another embodiment, a monofilament thread formed from a thermoplastic material is used as a core, and two or more threads or fibers of a non-thermoplastic material are wound, spun or wrapped around the inner component to form an outer component. In a further embodiment, a plurality of monofilament fibers are used to form a core portion and one or more staple fibers (short cut fibers) of a non-thermoplastic material are wound, spun or wrapped around the inner component to form an outer component.
An outer component described herein can form any proportion of the total weight of a fiber not inconsistent with the objectives of the present invention. In some embodiments, each of the fibers can comprise between about 20 wt.-% and about 80 wt.-% outer component, based on the total weight of the fiber. For example, in some cases, the fibers can comprise between about 20 wt.-% and about 70 wt.-% outer component, or between about 20 wt.-% and about 60 wt.-% outer component. In some instances, a fiber can comprise between about 30 wt.-% and about 80 wt.-% outer component, between about 40 wt.-% and about 80 wt.-% outer component, or between about 40 wt.-% and about 70 wt.-% outer component, based on the total weight of the fiber. Additionally, individual spun fibers may be plied to provide a stronger, more uniform fiber for weaving the desired fabric.
A fabric formed from fibers consistent with the foregoing description can have any structure or configuration not inconsistent with the objectives of the present invention. For example, in some embodiments, the fabric is woven. Any weaving pattern not inconsistent with the objectives of the present invention can be used. In some embodiments, the woven fabric is a plain woven fabric formed using a plain weave. In certain other cases, the woven fabric is formed using a satin weave or a twill weave. In addition, in some cases, the fabric can have a weight between about 3 oz./yd2 and about 5 oz./yd2, between about 3.5 oz./yd2 and about 4.5 oz./yd2, between about 3 oz./yd2 and about 4 oz./yd2, or between about 4 oz./yd2 and about 5 oz./yd2. Further, in some embodiments, the fabric can have a weight less than about 5 oz./yd2, such as less than about 4.5 oz./yd2. Further, fabrics usable in parachute buffer materials described herein can demonstrate a resistance to failure in a constant speed constant weight Draped Mandrel Test consistent with the description provided in the Examples provided hereinbelow.
In some embodiments, fabrics usable in parachute buffer materials described herein are provided uncoated or substantially uncoated. In such embodiments, fabrics described herein can provide superior characteristics or traits, such as high-speed fabric-on-fabric friction resistance. However, in certain preferred embodiments, parachute buffer materials can further comprise a coating disposed on at least one outer surface of the fabric. Such coatings are, in some instances, applied to fabrics described herein comprising fibers having an inner component formed from a thermoplastic material and an outer component formed from a non-thermoplastic material. In certain other cases, coatings described herein may be applied to other fabrics having a differing composition or structure. For example, in some embodiments, coatings described herein can be applied to cotton, nylon, polyester, cotton/polyester blended fabrics, or airplane cloth. Thus, in another aspect, methods of coating a fabric are described herein, the methods comprising coating a fabric with a coating or coating composition described herein. As described further hereinbelow, coating a variety of fabrics with a coating described herein can improve various properties of the fabrics, including for parachute buffer material applications.
Coatings for buffer fabrics or other parachute buffer materials described herein can comprise or include one or more components. In particular, a coating described herein can comprise one or more of a silicone-containing component, a wax component, a polymeric acrylic or urethane-containing component, and an antimicrobial agent-containing component. Various combinations of such components can also be used in a coating described herein.
In certain cases, the coating can comprise or a silicone or a silicone-containing component. For example, in some embodiments, a silicone-containing component of a coating comprises LUROL® PS-11158 (commercially available from Goulston Technologies, Inc., Monroe, N.C.), LUROL® PS-662 (Goulston Technologies, Inc.), XIAMETER® MEM-0008 Emulsion (commercially available from Dow Corning Corporation, Midland, Mich.), XIAMETER® MEM-0037 Emulsion (Dow Corning), XIAMETER® MEM-0939 Emulsion (Dow Corning), and/or combinations thereof. Not intending to be bound by theory, it is believed that disposing a coating comprising or containing a silicone or silicone-containing component can provide superior friction resistance relative to prior coatings. Further, a coating disposed on a parachute buffer material described herein can comprise one or more additional components or materials intended to provide desirable characteristics to at least one outer surface of the fabric.
In some embodiments, the coating further comprises a wax material such as a material or composition comprising a wax or mixture of waxes. For example, in some embodiments, the wax component could be a polyethylene wax or a paraffin wax or a vegetable wax or a combination of waxes. Such waxes can be applied to the outer surface of the fabric, typically from emulsion during the fabric finishing process or applied to the fiber as it is produced by rubbing the fiber against a wax disk. Not intending to be bound by theory, it is believed that some wax components or materials, applied as coatings, can, in some embodiments, provide enhanced fiber and/or fabric frictional properties.
In some embodiments, the coating further comprises a polymeric material or polymeric component such as a composition or material comprising an acrylic polymer or a polyurethane. For example, in some embodiments, a polymeric component of a coating comprises acrylic polymers such as those supplied by Dow Chemical under the trade name Rhoplex or by Stan Chem Inc. under the tradename StanChem or urethane polymers such as those supplied by Bond Polymers under the trade name Bondthane or by Hauthaway under the trade name Hauthane. Not intending to be bound by theory, it is believed that some polymeric components or materials used in coatings can, in some embodiments, provide enhanced fiber and/or fabric structure stability.
Additionally, a coating can further comprise one or more anti-wicking agents. An anti-wicking agent, in some embodiments, can provide hydrophobicity to a fiber or fabric to reduce, minimize, or eliminate absorption of moisture in the fiber or fabric. In some embodiments, an anti-wicking agent of a coating described herein can comprise a fluorochemical such as a fluorinated polymer or fluorinated hydrocarbon. For example, in some embodiments, a fluoro chemical component of a coating comprises fluoro polymer such as those supplied by 3M corporation under the trade name Scotch Guard or by Dakin under the trade name Unidyme or fluoro polymers/extenders such as those supplied by Clariant under the trade name Nuva.
Moreover, in some cases, a coating disposed on at least one outer surface of the fabric can comprise or contain an antimicrobial agent. An antimicrobial agent can be used in order to reduce, minimize, or eliminate growth of organisms such as viruses, fungi, or bacteria on or in the fabric. Any antimicrobial agent not inconsistent with the objectives of the present invention may be used. An antimicrobial agent, in some embodiments, comprises an inorganic composition, including metals and/or metal salts. In some embodiments, for example, an antimicrobial agent comprises metallic copper, zinc, or silver or a salt of copper, zinc, or silver or salts of these metallic elements. In other instances, an antimicrobial agent comprises an organic composition, including natural and synthetic organic compositions. In some cases, an antimicrobial agent comprises a β-lactam such as a penicillin or cephalosporin. An antimicrobial agent may also comprise an organic acid, such as lactic acid, acetic acid, or citric acid. In some embodiments, an antimicrobial agent comprises a quarternary ammonium species. A quarternary ammonium species, in some embodiments, comprises a long alkyl chain, such as an alkyl chain having a C8 to C28 backbone. In some cases, an antimicrobial agent comprises one or more of benzalkonium chloride, benzethonium chloride, methylbenzethonium chloride, cetalkonium chloride, cetylpyridinium chloride, cetrimonium, cetrimide, dofanium chloride, tetraethylammonium bromide, didecyldimethylammonium chloride, and domiphen bromide. In some embodiments, the antimicrobial agent may be a trialkoxy silane functionalized quaternary based on a C12 to C18 alkyl chain. For example, in some cases, an antimicrobial agent usable in a coating described herein can be LUROL® Ag 1000 (commercially available from Goulston Technologies, Inc.), MICROSILVER BG® (commercially available from Bio-Gate AG, Nurnberg, Germany), AEGIS MICROBE SHIELD® (commercially available from Microban International, Huntersville, N.C.), BIOSHIELD® 75 (commercially available from IndusCo, Ltd., Greensboro, N.C.), ZINC OMADINE® Enhanced CP Dispersion (commercially available from Lonza Group Ltd., Basel, Switzerland), and/or combinations thereof.
Some embodiments of parachute buffer materials described herein and fabrics utilized for such buffer materials are further illustrated in the following non-limiting examples.
Examples Parachute Buffer Materials or FabricsA series of fabrics consistent with various embodiments of parachute buffer materials described herein were prepared. A second series of reference fabrics were also prepared or acquired for comparative testing. A listing of the base fabric information for each of the Reference and Test Fabrics is provided in Table 1. Reference Fabric 1 and Test Fabric 1 were each formed from a plain weave of nylon fibers. Reference Fabric 2 and Test Fabric 2 were each formed from a plain weave of 100% polyester (PET) fibers. Reference Fabric 3 and Test Fabric 3 were formed from a plain weave comprising 35% cotton fibers and 65% PET fibers. Reference Fabric 4 and Test Fabric 4 were each formed from a plain weave of 100% cotton fibers. Reference Fabric 6 was a conventional, plain weave, cotton Airplane Cloth (APC). Test Fabric 5 and Test Fabric 6 were each formed from a Hybrid Fabric. The Hybrid Fabric was prepared from a core spun yarn prepared by spinning a long staple cotton outer component around a core or inner component of high strength, fully drawn polyester filament yarn. The core spun yarn was about 55 wt.-% polyester and about 45 wt.-% cotton, based on the total weight of the yarn. The yarn was then plied to provide a 46/2 count yarn used for weaving a fabric. The two ply, 46/2 core spun yarn was woven into a plain weave fabric. The fabric was prepared with 62 warp ends per inch and 62 weft ends per inch. The fabric was then scoured to remove any residual materials from the spinning and weaving process.
Test Fabrics 1-5 were each treated with a coating composition (“Coating 1”). Coating 1 comprised a silicone-containing component (LUROL PS 662), polymeric component (an acrylic polymer), and an antimicrobial agent (Aegis Microbial Shield). The properties of Reference Fabric 6 and Test Fabric 6 are provided below in Table 2.
In order to determine the time to break (“TTB”), an edge-sealed strip of parachute fabric is brought into contact with the surface of a fabric to be evaluated at a fixed high speed and with a predetermined tension applied, the following method was carried out.
Materials Time to BreakThe materials used for the test procedure were as follows: double sided tape, parachute canopy fabric, 50 cm×3.0 cm strips of a fabric to be tested, 100-500 g weights, a stopwatch, and a Draped Mandrel Tester (“DMT”). The DMT was constructed from a variable speed motor having a custom machined 6 inch aluminum wheel with side restraints and equipped with a tensiometer. An example of a DMT (100) usable in procedures carried out in the present example is illustrated in
First, the parachute canopy fabric (“PCF”) was cut into 1.25 cm×45 cm strips using a heat welder. A loop was created in the PCF (102) by folding the ends of the PCF (102) over and stapling the PCF (102) in place. The PCF (102) was then secured onto the wheel (104) of the DMT (100) using the double sided tape with an overlap of approximately 1 cm. Once the PCF (102) was placed on the wheel (104), the PCF (102) was folded down on both sides of the wheel (104) and fastened into position with the side restraints (106a, 106b), which were bolted onto the DMT motor (not shown). With the PCF (102) being fastened to the DMT (100), the fabric to be tested (108) was first attached at one end to the tensiometer (110). The fabric to be tested (108) was then draped across the top of the DMT wheel (104) and tensioned using the pre-tensioning weights (112). The cumulative angular contact of the test specimen against the friction-inducing surface (“wrap angle”) was maintained at 90°. Guide loops (114) were also used to ensure that the fabric to be tested (108) was held in the appropriate position in the middle section of the DMT wheel (104) during the test.
For a constant speed variable weight test, a standard speed can be selected that is appropriate to replicate parachute deployment conditions. For the present example, a speed of 1800 meters per minute was selected which corresponds to a value near the upper limit during parachute deployment. A constant pretension weight between 100 g and 500 g for each trial of each fabric was also used, and the test was stopped when the fabric to be tested generated a break in the parachute canopy fabric, at which point the TTB was measured, or until 90 seconds if the parachute canopy fabric did not fail. Weight was increased by 50 g for each subsequent trial, and the weight used for the highest weight pass and lowest weight fail were recorded.
Results Time to BreakThe results of the Draped Mandrel Test for Reference Fabrics 1-6 and Test Fabrics 1-6 at a speed of 1800 meters per minute are provided in Table 3 below. In Table 3 below, “Pass” refers to the maximum pretension weight for which a Reference Fabric or Test Fabric does not fail within 90 seconds. “Fail” refers to the pretension weight at which the Reference Fabric or Test Fabric fails along with the TTB in seconds.
Selected Reference and Test Fabrics were comparatively tested according to a number of additional test protocols. Namely, Reference Fabric 5 and Test Fabrics 5 and 6 were compared. Comparative data is provided in Table 4 below.
Various embodiments of the invention have been described in fulfillment of the various objectives of the invention. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptations thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the invention.
Claims
1. A parachute buffer material comprising:
- a fabric formed from a plurality of fibers, the fibers having an inner filament fiber component formed from a thermoplastic material and an outer staple fiber component formed from a non-thermoplastic material; and
- a coating disposed on at least one outer surface of the fabric, the coating comprising a silicone.
2. The parachute buffer material of claim 1, wherein the inner component is formed from a material selected from the group consisting of a nylon, a polyester, and a polyolefin.
3. The parachute buffer material of claim 1, wherein the outer staple fiber component is formed from a material selected from the group consisting of cotton, linen, rayon, acrylic, and an aramid.
4. The parachute buffer material of claim 1, wherein the outer component is formed from cotton.
5. The parachute buffer material of claim 1, wherein the inner component is a monofilament thread.
6. The parachute buffer material of claim 1, wherein the inner component comprises a plurality of monofilament threads.
7. The parachute buffer material of claim 1, wherein the outer component is spun around the inner component.
8. The parachute buffer material of claim 1, wherein the inner filament fiber component forms between about 10 wt.-% and about 70 wt.-% of the total weight of the fibers.
9. The parachute buffer material of claim 1, wherein the inner filament fiber component forms between about 30 wt.-% and about 50 wt.-% of the total weight of the fibers.
10. The parachute buffer material of claim 1, wherein the outer staple fiber component forms between about 20 wt.-% and about 80 wt.-% of the total weight of the fibers.
11. The parachute buffer material of claim 1, wherein the outer staple fiber component forms between about 40 wt.-% and about 70 wt.-% of the total weight of the fibers.
12. The parachute buffer material of claim 1, wherein the fabric is woven.
13. The parachute buffer material of claim 12, wherein the fabric is plain woven.
14. The parachute buffer material of claim 1, wherein the coating further comprises a silicone polymer.
15. The parachute buffer material of claim 1, wherein the coating further comprises a wax or blend of waxes.
16. The parachute buffer material of claim 1, wherein the coating further comprises an acrylic polymer and/or a polyurethane polymer.
17. The parachute buffer material of claim 1, wherein the coating further comprises an anti-wicking agent.
18. The parachute buffer material of claim 1, wherein the coating further comprises an antimicrobial agent.
Type: Application
Filed: Jun 10, 2016
Publication Date: Mar 2, 2017
Inventors: Thomas W. THEYSON (Matthews, NC), Roger J. Crossfield (Matthews, NC), John T. Wilson (Charlotte, NC)
Application Number: 15/178,689
