| Highly cut-resistant yarn and protective articles made there from -> Monitor Keywords |
|
|
  Highly cut-resistant yarn and protective articles made there fromUSPTO Application #: 20080090479Title: Highly cut-resistant yarn and protective articles made there from Abstract: A cut-resistant composite yarn, comprising a high strength organic fiber having a tenacity greater than 15 grams per denier and a hard-particle-filled thermoplastic fiber useful in making fabrics from which protective articles, such as gloves are made. (end of abstract) Agent: E I Du Pont De Nemours And Company Legal Patent Records Center - Wilmington, DE, US Inventor: Alan Sanford Koralek USPTO Applicaton #: 20080090479 - Class: 442189000 (USPTO) Related Patent Categories: Fabric (woven, Knitted, Or Nonwoven Textile Or Cloth, Etc.), Woven Fabric (i.e., Woven Strand Or Strip Material), Including Strand Which Is Of Specific Structural Definition The Patent Description & Claims data below is from USPTO Patent Application 20080090479. Brief Patent Description - Full Patent Description - Patent Application Claims
[0001] This is a divisional application that claims priority from U.S. application Ser. No. 10/997,721, filed on Nov. 23, 2004. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates to cut-resistant fibers and yarns and particularly their use in gloves and other protective apparel. [0004] 2. Description of Related Art [0005] Improved resistance to cutting with a sharp edge has long been sought. Cut-resistant gloves are beneficially utilized in the meatpacking industry and in automotive applications. As indicated by U.S. Pat. Nos. 4,004,295, 4,384,449, and 4,470,251, and by EP 458,343, gloves providing cut resistance have been made from yarn which includes flexible metal wire or which consist of highly oriented fibers having high modulus and high tensile strength, such as aramids, thermotropic liquid crystalline polymers, and extended chain polyethylene. A drawback to gloves made from yarn that includes flexible metal wire is hand fatigue with resultant decreased productivity and increased likelihood of injury. Moreover, with extended wear and flexing, the wire may fatigue and break, causing cuts and abrasions to the hands. In addition, the wire will act as a heat sink when a laundered glove is dried at elevated temperatures, which may reduce tensile strength of the yarn or fiber, thereby decreasing glove protection and glove life. [0006] Improved flexibility and comfort and uncomplicated laundering are desirable in cut-resistant, protective apparel. Therefore, there is a need for a flexible, cut-resistant fiber that retains its properties when routinely laundered. Such a fiber may be advantageously used in making protective apparel, in particular highly flexible, cut-resistant gloves. [0007] Polymers have been mixed with particulate matter and made into fibers, but not in a way that significantly improves the cut resistance of the fiber. For example, small amounts of particulate titanium dioxide have been used in polyester fiber as a delustrant. Also used in polyester fiber is a small amount of colloidal silicon dioxide, which is used to improve gloss. Magnetic materials have been incorporated into fibers to yield magnetic fibers. Examples include: cobalt/rare earth element intermetallics in thermoplastic fibers, as in published Japanese Patent Application No. 55/098909 (1980); cobalt/rare earth element intermetallics or strontium ferrite in core-sheath fibers, described in published Japanese Patent Application No. 3-130413 (1991); and magnetic materials in thermoplastic polymers, described in Polish Patent No. 251, 452 and also in K. Turek et al., J. Magn. Magn. Mater. (1990), 83 (1-3), pp. 279-280. Also, U.S. Pat. No. 5,597,649 is directed to a yarn, which is a composite of a high modulus fiber and a particle-filled fiber, wherein the high modulus fiber can be an aramid fiber. [0008] Various kinds of gloves have been made in which metal has been included in the fabrication of the glove to impart protective qualities to the glove. For example, U.S. Pat. Nos. 2,328,105 and 3,185,751 teach that a flexible, X-ray shield glove may be made by treating sheets of a suitable porous material with a finely divided, heavy metal which may be lead, barium, bismuth or tungsten, or may be made from a latex or dispersion containing heavy metal particles. As illustrated by U.S. Pat. No. 5,020,161, gloves providing protection against corrosive liquids have been made with a metal film layer. These gloves also do not appear to have significantly improved cut resistance. SUMMARY OF THE INVENTION [0009] In one embodiment, this invention is a cut-resistant composite yarn, comprising a high strength organic fiber having a tenacity greater than 15 grams per denier and a hard-particle-filled thermoplastic fiber useful for making cut-resistant fabrics that can be made into protective articles, such as gloves, aprons, chaps, sleeves, and the like. BRIEF DESCRIPTION OF THE DRAWINGS [0010] FIGS. 1a and 1b are schematic sketches of the chamber used in the Torture Chamber Test. [0011] FIG. 2 is a sketch of a test glove as used in the Torture Chamber Test. DETAILED DESCRIPTION OF THE INVENTION [0012] The invention is a highly cut resistant yarn and articles for personal protective use such as gloves, aprons, chaps, and the like and the process for manufacturing them. The articles are made from yarns that are a combination of a high strength organic fiber and a thermoplastic carrier fiber filled with hard particles. [0013] Within the embodiment of this invention the term "high strength organic fiber" is understood to mean a fiber with a tenacity greater than 15 grams per denier that is formed by any of the polymerization reactions commonly known in the art from monomers based on a carbon backbone. Preferably, high strength organic fibers do not include carbon fiber. Typical high strength organic fibers embodied by this invention include but are not limited to fibers with a tenacity greater than 15 grams per denier formed from para-aramid, polybenzazole, polybenzoxazole, polybenzothiazole, polybenzimidazole, polyacrylate, and copolymers thereof. [0014] In one embodiment of this invention, the carrier fiber is formed from an isotropic semi-crystalline polymer. Typical fibers are fibers formed from polymers such as poly (alkylene terephthalate), poly (alkylene naphthalate), poly (arylene sulfide), aliphatic, and aliphatic-aromatic polyamide, and polyesters made from monomer units derived from cyclohexanedimethanol and terephthalic acid. In another embodiment of this invention, the carrier fiber is formed from a liquid crystalline polymer (LCP) that is preferably thermotropic. Typical LCP fibers are formed from polymers such as aromatic polyester, aliphatic-aromatic polyester, aromatic poly (estercarbonate), aliphatic-aromatic poly (esteramide), aromatic poly (esterimide), aromatic poly (esteramide), aromatic polyamide, aliphatic-aromatic polyamide, and poly (azomethine). [0015] The hard particles used to fill the thermoplastic fibers of this invention may be characterized as having a MOHS hardness value of greater than 5. Preferably, the average particle size distribution of the hard particles will be in the range of 1 to 6 microns. Typical materials that may comprise the hard particles include but are not limited to tungsten, copper, brass, bronze, aluminum, steel, iron, monel, cobalt, titanium, magnesium, silver, molybdenum, tin, zinc, aluminum oxide, tungsten carbide, metal nitrides, metal sulfates, metal phosphates, metal borides, silicon dioxide, silicon carbide, baddelyte, chloritoid, clinozoiste, chondrodite, euclasite, petalite, sapphire, spodumene, staurolite, clay, or alumina. [0016] In one embodiment of this invention, the hard particle filled thermoplastic fiber is a thermoplastic fiber in which the hard particle filler is essentially uniformly distributed. The hard particle filler is present in the amount of 0.1 to 10 (optionally 0.1 to 5) weight percent based on the total weight of the particle filled fiber. [0017] In another embodiment of this invention, the hard particle filled thermoplastic fiber is the core fiber of a sheath/core fiber in which the hard particle filler is essentially uniformly distributed within the core material of the sheath/core fiber. Preferably, the hard particle filler is present in the amount of 0.1 to 10 (optionally 0.1 to 5) weight percent based on the total weight of the sheath/core fiber. [0018] The articles are preferably made by knitting from yarns that are comprised of a combination of poly (paraphenylene terephthalamide) fiber sold by E.I. du Pont de Nemours and Company (DuPont), Wilmington, Del. under the trade name KEVLAR.RTM. and polyester CRF (cut resistant fibers). The polyester CRF is preferably an alumina-filled (about 10%) multifilament yarn as generally described in U.S. Pat. No. 5,851,668. The polyester is preferably poly (ethylene terephthalate). The polyester cut resistant fibers are available from Honeywell under the trademark Barricut.RTM.. The inventive yarns comprise about 32 to 65% of cut resistant polyester fiber; however, as the percentage cut resistant polyester increases beyond about 65%, the performance in cut protection decreases. The cut-resistant fabric that is a combination of KEVLAR.RTM. and polyester has cut resistance as measured by ASTM F1790-97 greater than that of a comparable weight fabric made entirely of either fiber. Additionally, unlike an article made wholly of polyester cut-resistant fabric, an article made of the inventive fabric is very resistant to cutting in shearing operations, such as with scissors. [0019] Further, such articles in the form of gloves demonstrate exceptionally long life in the torture chamber test (TCT). The inventive gloves demonstrated dramatically better performance than gloves made either wholly of KEVLAR.RTM. or wholly of polyester CRF. Dupont developed the TCT (described in detail below) to evaluate the performance of cut resistant material in extreme conditions, where standard cut protection performance tests do not accurately predict performance in real-life situations. [0020] The ply-twisted yarns of this invention are made by twisting together at least two individual single yarns. It is well known in the art to twist single yarns together to make ply-twisted yarns. Each single yarn can be, for example, a collection of staple fibers spun into what is known in the art as a spun staple yarn. Continue reading... Full patent description for Highly cut-resistant yarn and protective articles made there from Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Highly cut-resistant yarn and protective articles made there from patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Highly cut-resistant yarn and protective articles made there from or other areas of interest. ### Previous Patent Application: Phase-separation-controlled polybutadiene resin composition and printed wiring board using the resin composition Next Patent Application: Biodegradable polyester resin composition Industry Class: Fabric (woven, knitted, or nonwoven textile or cloth, etc.) ### FreshPatents.com Support Thank you for viewing the Highly cut-resistant yarn and protective articles made there from patent info. IP-related news and info Results in 1.87713 seconds Other interesting Feshpatents.com categories: Accenture , Agouron Pharmaceuticals , Amgen , AT&T , Bausch & Lomb , Callaway Golf |
||
