Patent ID: 9533480
Date: 2017-01-03
CPC Classifications: B29C,B32B,F41H,Y10T

Claim:
1. A laminate comprising multiple uni-directional tape plies, each tape ply being fabricated from a plurality of multi-filament tape precursors, each multi-filament tape precursor being formed from at least one ultra-high molecular weight polyethylene gel spun, multi-filament yarn and wherein each multi-filament tape precursor is produced by a process comprising: a) selecting at least one polyethylene multi-filament yarn, said yarn having a c-axis orientation function of at least 0.96, an intrinsic viscosity when measured in decalin at 135° C. by ASTM D1601-99 of from about 7 dl/g to about 40 dl, g, and said yarn having a tenacity of from about 15 g/d to about 100 g/d as measured by ASTM D2256-02 at a 10 inch (25.4 cm) gauge length and at an extension rate of 100%/min; b) placing said yarn under a longitudinal tensile force and subjecting said yarn to at least one transverse compression step to flatten, consolidate and compress said yarn at a temperature of from about 25° C. to about 137° C., thereby forming a tape article having an average cross-sectional aspect ratio at least about 10:1, each said compression step having an outset and a conclusion wherein the magnitude of said longitudinal tensile force on each said yarn or tape article at the outset of each said compression step is substantially equal to the magnitude of the longitudinal tensile force on the yarn or tape article at the conclusion of that same compression step, and is at least about 0.25 kilogram-force; c) stretching said tape article at least once at a temperature in the range of from about 130° C. to about 160° C. at a stretch rate of from about 0.001 min d) optionally repeating step b) one or more times at a temperature from about 100° C. to about 160° C.; e) optionally repeating step c) one or more times; f) optionally relaxing the longitudinal tensile force between any of steps b) to e); g) optionally increasing the longitudinal tensile force between any of steps b) to e); h) cooling said tape article to a temperature less than about 70° C. under tension; wherein the laminate optionally comprises resin other than the gel spun ultra-high molecular weight polyethylene, wherein said resin comprises not more than five percent by weight of the laminate.