Process and product of high strength uhmw pe fibers

A solid ultra-high molecular weight polyethylene (UHMW PE) filament produced by a process comprising the steps of:

• a) selecting an UHMW PE having an intrinsic viscosity (IV) from about 5 dl/g to about 45 dl/g when measured in decalin at 135° C., wherein a 10 wt. % solution of the UHMW PE in mineral oil at 250° C. has a Cogswell extensional viscosity (λ) in accordance with the following formula:
• λ≧5,917(IV)0.8;
• b) dissolving the UHMW PE in a solvent at elevated temperature to form a solution having a concentration of from about 5 wt. % to about 50 wt. % of UHMW PE;
• c) discharging the solution through a spinneret to form solution filaments;
• d) cooling the solution filaments to form gel filaments;
• e) removing solvent from the gel filaments to form solid filaments containing less than about 5 wt. % of solvent;
• f) stretching at least one of the solution filaments, the gel filaments and the solid filaments to a combined stretch ratio of at least 10:1, wherein the solid filaments are stretched to a ratio of at least 2:1. stretch ratio of at least 10:1, wherein at least 2:1 is of the solid filaments.

A solid ultra-high molecular weight polyethylene (UHMW PE) filament produced by a process comprising the steps of:

• a) selecting an UHMW PE having an intrinsic viscosity from 5 to 45 dl/g when measured in decalin at 135° C., wherein a 10 wt. % solution of the UHMW PE in mineral oil at 250° C. has a Cogswell extensional viscosity and a shear viscosity such that the Cogswell extensional viscosity is at least eight times the shear viscosity;
• b) dissolving the UHMW PE in a solvent to form a solution having a concentration of from about 5 wt. % to about 50 wt. % of UHMW PE;
• c) discharging the solution through a spinneret to form solution filaments;
• d) cooling the solution filaments to form gel filaments;
• e) removing solvent from the gel filaments to form solid filaments containing less than about 5 wt. % of solvent;
• f) stretching at least one of the solution filaments, the gel filaments and the solid filaments to a combined stretch ratio of at least 10:1, wherein the solid filaments are stretched to a ratio of at least 2:1.