Multi-layered flexible fiber-containing articles
AssigneeAllied Corporation
InventorsGary A. Harpell, Igor Palley, Dusan C. Prevorsek
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Abstract
The present invention provides improved, flexible articles of manufacture comprising a plurality of first flexible layers arranged in a first portion of said article, each of said first layers consisting essentially of fibers, the fibers of each of said flat layers comprising fibers having a tensile modulus of at least about 300 g/denier and a tenacity of at least about 15 g/denier and a plurality of second flexible layers arranged in a second portion of said article, each of said second flexible layers comprising fibers, the resistance to displacement of fibers in each of said second flexible layers being greater than the resistance to displacement of fibers in each of said first flexible layers.
Claims47
An article of manufacture comprising a plurality of first flexible layers arranged in a first portion of said article each of said first flexible layers consisting essentially of uncoated fibers comprising fiber selected from the group of polyolefin fibers, polyvinyl alcohol fibers and polyacrylonitrile fibers having a tensile modulus of at least 300 g/denier and a tenacity of at least about 15 g/denier and a plurality of second flexible layers arranged in a second portion of said article, each of said second flexible layers consisting essentially of uncoated fibers, the resistance to displacement of fibers in each of said second flexible layers being greater than the resistance to displacement of fibers in each of said first flexible layers.
An article of manufacture comprising a plurality of first flexible layers arranged in a first portion of said article, each of said first flexible layers comprising polyethylene fibers having a weight average molecular weight of at least about 500,000, a modulus of at least about 500 g/denier and a tenacity of at least about 15 g/denier, and a plurality of second flexible layers arranged in a second portion of said article, each of said second flexible layers being substantially free of polyethylene fiber, the resistance to displacement of fibers in each of said second flexible layers being greater resistance to displacement of fibers in each of said first flexible layers.
An article of manufacture comprising a plurality of first flexible layers arranged in a first portion of said article, at least one of said first flexible layers consisting essentially of uncoated fiber selected from the group of polyolefin fiber, polyvinyl alcohol fiber, polyacrylonitrile fiber and mixtures thereof, at least some of said fiber having a tensile modulus of at least about 300 g/denier and a tenacity of at least about 15 g/denier, and a plurality of second flexible layers arranged in a second portion of said article, at least one of said second flexible layers comprising fiber selected from the group of polyolefin fiber, polyvinyl alcohol fiber, polyacrylonitrile fiber and mixtures thereof and a material selected from the group of polymers having ethylene or propylene crystallinity, polymers having a modulus of less than about 6,000 psi, and mixtures thereof, the resistance to displacement of fibers in each of said second flexible layers being greater than the resistance to displacement of fibers in each of said first flexible layers.
An article of manufacture comprising a plurality of flexible, fiber-containing layers, said article having an RIR value of at least about 1.25, wherein the RIR value is the value of RI.sub.1 divided by RI.sub.2 where RI.sub.1 is equal to the higher resistance index, RI, valve and RI.sub.2 is the lower resistance index, RI, value, the resistance index RI being determined as ##EQU6## where n=number of consecutive impact effective layers (beginning with the first impact effective layer nearest a face of the article) constituting substantially one half of the areal density of all of the impact effective layers of the article, an impact effective layer being defined as any fiber containing layer of said article wherein said fibers consist of fibers having a tenacity of at least about 15 g/denier and any fiber containing layer of said article having a specific energy absorption value of at least about one third of the highest specific energy absorption value calculated for any layer of the article;
- F.sub.i is equal to the resistance to fiber displacement value of the i.sup.th layer;
- and AD.sub.i is equal to the areal density of the i.sup.th layer, F.sub.i being determined by the equation ##EQU7## where b.sub.i =the number of broken fibers in the i.sup.th layer produced by the impact of a ballistic threat having an impact velocity of at least about 90 percent of the V.sub.50 value of an article constructed essentially from 3n i.sup.th layers, n=the number of layers removed and individually inspected to determine the number of broken fibers in each layer i=1 to i=n, and x=the number of fibers within the impact area of each layer i=1 to i=n, the impact area being defined as as area of the layer substantially equal to the initial cross sectional area of the ballistic threat (measured in a plane normal to the direction of travel of the ballistic threat).
An article of manufacture comprising a plurality of fiber containing layers, each fiber containing layer having an F value different from any other of said fiber containing layers, wherein ##EQU8## where b.sub.i =the number of broken fibers in the i.sup.th layer produced by the impact of a ballistic threat having an impact velocity of at least about 90 percent of the V.sub.50 value of an article constructed essentially from 3n i.sup.th layers, n=the number of layers removed and individually inspected to determine the number of broken fibers in each layer 1 through n, and x=the number of fibers within the impact area of each layer 1 through n, the impact area being defined as as area of the layer substantially equal to the initial cross sectional area of the ballistic threat (measured in a plane normal to the direction of travel of the ballistic threat).
An article of manufacture comprising a plurality of first layers arranged in a first portion of said article, each of said first layers consisting essentially of polyolefin fiber, and a plurality of second layers, each of said second layers comprising fiber, the fiber in said second layers having a greater resistance to displacement than the fiber in said first layers, the fiber of said second layers consisting of polyethylene fiber having a weight average molecular weight of at least about 500,000, a modulus of at least about 500 g/denier, a tenacity of at least about 25 g/denier, and a denier no greater than about 50% of the fiber denier of said polyolefin fiber and not greater than about 500.
Dependencies are inferred from the claim text.