Patent ID: 7115318

Claim:
A polyethylene multi-filament yarn comprising a polyethylene having an intrinsic viscosity in decalin at 135° C. of from about 5 dl/g to 35 dl/g, fewer than about two methyl groups per thousand carbon atoms, and less than about 2 wt. % of other constituents, said multi-filament yarn having a tenacity of at least 17 g/d as measured by ASTM D2256-02, wherein filaments of said yarn have a parameter of intrachain cooperativity of the melting process, ν, of at least 535 as determined by differential scanning calorimetry (DSC) of the first polyethylene melting endotherm at a heating rate extrapolated to 0° K/min from at least 3 melting scans at heating rates less than 2° K/min, said DSC calorimetry being conducted of a filament segment of about 0.03 mg mass cut into pieces of about 5 mm length wrapped in parallel array in a Wood's metal foil and placed in an open sample pan, and the intensity of the (002) x-ray reflection of at least one said filament of said yarn shows two distinct peaks measured at room temperature under no external load.