Patent Application
20070271965
A more complete appreciation of the present invention, and many of the attendant advantages thereof, will be readily ascertained and obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
The term “fiber” as used herein refers to a fundamental component used in the assembly of yarns and fabrics. Generally, a fiber is a component which has a length dimension which is much greater than its diameter or width. This term includes ribbon, strip, staple, and other forms of chopped, cut or discontinuous fiber and the like having a regular or irregular cross section. “Fiber” also includes a plurality of any one of the above or a combination of the above.
As used herein, the term “high performance fiber” means that class of synthetic or natural non-glass fibers having high values of tenacity greater than 10 g/denier, such that they lend themselves for applications where high abrasion and/or cut resistance is important. Typically, high performance fibers have a very high degree of molecular orientation and crystallinity in the final fiber structure.
The term “filament” as used herein refers to a fiber of indefinite or extreme length such as found naturally in silk. This term also refers to manufactured fibers produced by, among other things, extrusion processes. Individual filaments making up a fiber may have any one of a variety of cross sections to include round, serrated or crenular, bean-shaped or others.
The term “yarn” as used herein refers to a continuous strand of textile fibers, filaments or material in a form suitable for knitting, weaving, or otherwise intertwining to form a textile fabric. Yarn can occur in a variety of forms to include a spun yarn consisting of staple fibers usually bound together by twist; a multi filament yarn consisting of many continuous filaments or strands; or a mono filament yarn which consist of a single strand.
The term “composite yarn” (or “engineered yarn”) refers to a yarn prepared from two or more yarns (or “ends”), which can be the same or different. Composite yarn can occur in a variety of forms wherein the two or more ends are in differing orientations relative to one another, so long as the final composite yarn containing the two or more ends is stably assembled (i.e. will remain intact unless forcibly separated or disassembled). The two or more ends can, for example, be parallel, wrapped one around the other(s), twisted together, or combinations of any or all of these, as well as other orientations, depending on the properties of the composite yarn desired. Suitable composite yarns, which may be formed into fabric by any desired process, preferably knit or woven into the fabric, include, but are not limited to, those as described in U.S. Pat. No. 4,777,789, U.S. Pat. No. 4,838,017, U.S. Pat. No. 4,936,085, U.S. Pat. No. 5,177,948, U.S. Pat. No. 5,628,172, U.S. Pat. No. 5,632,137, U.S. Pat. No. 5,644,907, U.S. Pat. No. 5,655,358, U.S. Pat. No. 5,845,476, U.S. Pat. No. 6,212,914, U.S. Pat. No. 6,230,524, U.S. Pat. No. 6,341,483, U.S. Pat. No. 6,349,531, U.S. Pat. No. 6,363,703, U.S. Pat. No. 6,367,290, and U.S. Pat. No. 6,381,940, each to Kolmes, the contents of each of which are hereby incorporated by reference. Another term by which composite yarns are known is “engineered yarn”.
The present invention relates to a shaped knit protective fabric panel having a cut resistance of at least 500, according to the ASTM-F1790-04 (Standard Cut Test on Composite Yam), and a fabric weight of 27.9 ounces/sq. yd or less, and protective garments and coverings made therefrom.
The fabric panel of the present invention comprises sufficient cut, slash and/or abrasion resistant yarn to provide the fabric with the necessary level of cut resistance, such that the fabric has a cut resistance of at least 500 as measured by ASTM-F1790-04, the Standard Cut Test on Composite Yam, the entire contents of which are hereby incorporated by reference. These cut, slash and/or abrasion resistant yarns can be any high performance yarn, a composite yarn, a yarn blend comprising one or more high performance or composite yarns, etc. Suitable high-performance yarns include, but are not limited to, extended chain polyethylene (such as SPECTRA or DYNEEMA), aramids (such as KEVLAR), and liquid crystalline polyesters (such as VECTRAN). The fabric preferably has a cut resistance of from 500 to 6200, more preferably from 1000 to 6200. The fabric preferably may contain one or more composite yarns, either alone or in combination with any other natural or synthetic fiber. Such natural or synthetic fibers include, but are not limited to, cotton, wool, nylon, polyester, rayon, cellulose acetate, etc.
The fabric of the present invention further has a fabric weight that is sufficiently lightweight to be practical for wearing, having a fabric weight of no more than 27.9 ounces/square yard (OPSY), preferably a fabric weight of from 7 to 27.9 OPSY, more preferably from 8 to 20 OPSY, most preferably from 8 to 17 OPSY.
The protective garments of the present invention are made from the protective fabric and can be any form of garment, including, but not limited to, shirts, socks, sweaters, vests, undergarments, pants, jumpsuits, dickeys, and head coverings. The protective garment of the present invention can provide one or more of the following advantages, including the prevention or reduction of injury to the wearer, resistance to damage, and light-weight construction. In a preferred embodiment of the invention, the protective garment comprises a fabric made entirely from cut, slash and/or abrasion resistant composite yarns. The garments are made according to any known method useful for preparing garments from fabrics. Preferably, the garments are made by shaped knitting during preparation of the fabric. Shaped knitting is a process by which the various panels of a garment are formed directly in the shape needed for assembly, during the knitting process. This is preferred for the present invention, since the fabrics of the present invention have cut and slash resistance and are therefore extremely difficult to cut using conventional fabric cutting means. While it is possible to cut the fabric, the cutting process is very hard on the cutting surfaces, significantly reducing the interval between servicing of the cutting equipment, and thus increasing the cost of operations. Accordingly, shaped knitting is preferably used to prepare the panels of fabric which are assembled to prepare the present invention garments. These panels are then linked together to form the garment. Many types of seam construction can be used to attach panels to one another. Since these panels have been shaped during their construction, linking, looping of collars or cup seaming are the most preferred, due to the higher comfort provided by the seam against the wearer's skin as well as strength. The Knit Construction may be in various Gauges such as 3, 4, 5, 6, 7, 8, 10, 12, 13, 14, 16, and 18 gauges wherein within the context of the present invention, the term “gauge” means needles per inch on the specific machine on which the pieces are knit. By way of example, 18 Gauge would normally make a fine textured piece, whereas a 3 gauge piece would normally be of a coarser texture.
In a preferred embodiment, the fabric is prepared into a garment or other type of covering that is seamless. Such garments or coverings can be prepared using a knitting machine such as the “WholeGarment” machine sold by Shima Seiki Mfg., Ltd. of Wakayarna, Japan, or the “Stoll Knit-and-Wear” machinery of H. Stoll & Co. Kg. of Reutlingen, Germany. These garments or coverings could have any desired construction, but would typically be substantially tubular knit in construction, although the tubular construction could have apertures through which appendages could protrude when wearing the garment, or when the covering is applied to an object. The coverings made from the present invention fabrics could be any type of covering, including but not limited to, book covers, wiring protection, sacks, and scuba air hose covers (or socks).
As exemplary embodiments, fabrics are made from the following types of yarns:
Core: Fiberglass #450
Bottom cover: 215 denier SPECTRA wrapped at 9.7 turns per inch (tpi)
Middle cover: 70 denier polyester (PET) wrapped at 18.5 tpi
Top cover: 70 denier polyester (PET) wrapped at 16.3 tpi
Core 1: Spun polyester 36/1 combined with
Core 2: Fiberglass #225 wrapped by 0.002 in wire at 9.9 tpi, followed by a top cover of 375 denier SPECTRA at 7.8 tpi
Bottom cover: 150 denier Polyester (PET) wrapped at 7.5 tpi
Top cover: Spun polyester 36/1 wrapped at 5 tpi
Core 1: 650 denier SPECTRA
Core 2: 3 parallel strands of wire of 0.0035, 0.003 and 0.003 in
Cores 1 and 2 being parallel in orientation
Bottom cover: 1000 denier polyester (PET) wrapped at 9.9 tpi
Top cover: 1000 denier polyester (PET) wrapped at 8.0 tpi
Core: 70 denier LYCRA T-162C (from DuPont)
Cover: 375 denier SPECTRA wrapped at 7.8 tpi
The resulting fabrics have the cut resistances (measured according to ASTM-F1790-04) and fabric weights shown below:
As an example of a garment prepared according to the present invention,
Numerous additional modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.
