High tenacity, high elongation polypropylene fibers, their manufacture, and use
AssigneeHercules Incorporated
InventorJames P. Modrak
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Abstract
Spinning polypropylene at relatively high temperatures with delayed quenching, and drawing at relatively high temperatures with moderate draw ratios, provides fibers having an improved tensile factor, especially improved elongation, and can be used to produce fibers also having a high tenacity. The fibers are particularly useful for reinforcement applications when provided in the form of staple fibers and exhibit a tensile factor TE.sup.0.50 of at least about 60, where T is tenacity (gpd) and E is elongation (percent), especially those having a tenacity of at least about 8 gpd and/or an elongation of at least about 25%, and most especially those having a tenacity of at least about 10 gpd and elongations of 50% to 400%.
Claims60
A melt-spun fiber comprising a propylene polymer and having a tensile factor TE.sup.0.50 of at least 60, wherein T is the tenacity of the fiber in grams per denier and is at least 10 gpd, and E is the percent elongation and is 25-400%.
A melt-spun fiber comprising a propylene polymer and having a tensile factor TE.sup.0.50 of at least 62, wherein T Is the tenacity of the fiber in grams per denier and is at least 6.5 grams per denier, and E is the percent elongation and is 25-400%.
A melt-spun fiber comprising a propylene polymer and having a tensile factor TE.sup.0.50 of at least 70, wherein T is the tenacity of the fiber in grams per denier and is at least 5.5 grams per denier, and E is the percent elongation and is 25-400%.
A melt-spun fiber comprising polypropylene and having a tenacity T in grams per denier of at least about 7.0 grams and a percent elongation E of 35-400%.
Dependencies are inferred from the claim text.