| US 7,611,652 B2 | ||
| Monoxially-oriented and annealed films with high cross machine toughness and related process | ||
| Larry L. English, Ringgold, Ga. (US); and Jeffrey W. Adams, Sand Rock, Ala. (US) | ||
| Assigned to Shaw Industries Group, Inc., Dalton, Ga. (US) | ||
| Filed on Jun. 02, 2006, as Appl. No. 11/446,039. | ||
| Claims priority of provisional application 60/739136, filed on Nov. 22, 2005. | ||
| Prior Publication US 2007/0116953 A1, May 24, 2007 | ||
| Int. Cl. B29C 47/88 (2006.01); B29C 55/04 (2006.01) | ||
| U.S. Cl. 264—210.5 [264/146; 264/210.7; 264/235] | 6 Claims |
| 1. A process for imparting high cross machine toughness to polymer film tape yarns, comprising:
forming a film from an impact copolymer:
subjecting said film to monoaxial orientation involving drawing at stages where said film is sequentially directed over a
series of rollers as the film is sequentially subjected to a stage of preheating, then a stage of drawing and then a stage
of tempering;
wherein said stage of tempering said film is conducted at temperatures of from between about 20 to about 45 percent lower
than the temperature at which said film is subjected to during the stage of drawing;
annealing said film, wherein said film has an average cross machine toughness value of at least 3,000 lbs/in2 after the annealing step; and
slitting said film subsequent to said annealing.
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