Fluoropolymer Fiber Composite Bundle

Abstract

A composite bundle for repeated stress applications comprising at least one fiber of a high strength material, at least one fiber of fluoropolymer, wherein the fluoropolymer fiber is present in an amount of about 40% by weight or less.

Description

RELATED APPLICATION [0001] The present application is a divisional application of pending U.S. patent application Ser. No. 11 / 056,074 filed Feb. 11, 2005.FIELD OF THE INVENTION [0002] The present invention relates to a fluoropolymer composite bundle and, more particularly, to ropes and other textiles made of composite bundles including fluoropolymers such as polytetrafluoroethylene (PTFE). DEFINITION OF TERMS [0003] As used in this application, the term “fiber” means a threadlike article as indicated at 16 and 18 of FIG. 1. Fiber as used herein includes monofilament fiber and multifilament fiber. A plurality of fibers may be combined to form a “bundle”14 as shown in FIG. 1. When different types of fibers are combined to form a bundle, it is referred to herein as a “composite bundle.” A plurality of bundles may be combined to form a “bundle group”12 as shown in FIG. 1. A plurality of bundle groups may be combined to form a “rope”10 as shown in FIG. 1 (although alternative rope constr...

AI Technical Summary

Benefits of technology

The present invention provides a composite bundle for repeated stress applications that includes at least one high strength fiber and at least one fluoropolymer fiber. The amount of fluoropolymer fiber present in the bundle is about 40% by weight or less. The high strength fiber can be liquid crystal polymer or ultrahigh molecular weight polyethylene, or a combination of both. The fluoropolymer fiber can be an ePTFE fiber, which can be a monofilament or multifilament, either low or high density. The composite bundle has a ratio of break strengths after abrasion test of at least 1.8, preferably 3.8, or 4.0. The fluoropolymer fiber can also include a filler or lubricant. The invention also provides a method of reducing abrasion- or friction-related wear of a fiber bundle in repeated stress applications while maintaining the strength of the bundle by including at least one filament of fluoropolymer. The invention also provides various products made from the inventive composite bundle, such as rope, belt, net, sling, cable, woven fabric, nonwoven fabric, or tubular textile.

Problems solved by technology

They are subjected to high tensile and bending stresses in use as well as a wide range of environmental challenges.

The abrasion damages the fibers, thereby decreasing the life of the rope.

LCP fibers are particularly susceptible to this failure mechanism.

This internal heat severely weakens the fibers.

The UHMWPE fibers suffer from this mode of failure.

All such ropes, however, still perform inadequately in some applications, failing due to one or more of the three above-mentioned mechanisms.

For example, UHMWPE fibers and high strength fibers, such as LCP fibers, have been blended to create a large diameter rope with better abrasion resistance, but they are still not as effective as desired.

Typically such coatings wear off relatively quickly.

Jackets add weight, bulk, and stiffness to the rope, however.

In sum, none of the known attempts to improve the life of ropes or cable have provided sufficient durability in applications involving both bending and high tension.

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