Yarn of staple fibers from multi-filaments by stretching and controlled breaking and articles made therefrom

Abstract

A single-strand yarn includes a plurality of intimately associated staple fibers made from N strands of multi-filaments by stretching and controlled breaking, and then spun by a spinning process, where N is a natural number. Within the single-strand yarn of a sampling length according to the invention, a ratio of the number of the staple fibers, whose length is equal to or greater than 60% of a setup fiber length to the total number of the staple fibers, is equal to or greater than 60%. The sampling length is equal to or less than 10 meters. The setup fiber length is equal to or larger than 65 mm. The dispersion of the weight distribution in the average length of the single-strand yarn according to the invention is equal to or less than 60%.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This utility application claims priority to Taiwan Application Serial Number 109125696, filed Jul. 30, 2020, which is incorporated herein by reference.BACKGROUND OF THE INVENTION1. Field of the Invention[0002]The invention relates to a single-strand yarn and a plied yarn made from at least one strand of multi-filaments by stretching and controlled breaking, and a textile article made therefrom, and more in particular, to a single-strand yarn or a plied yarn having high strength and high diameter uniformity and being made from a plurality of intimately associated staple fibers made from multi-filaments by stretching and controlled breaking, and a textile article made therefrom.2. Description of the Prior Art[0003]Continuous filaments made of various materials will be further broken into staple fibers and spun into yarns due to application and cost considerations. These yarns spun from discontinuous staple fibers necessarily have poorer prop...

AI Technical Summary

Benefits of technology

The invention relates to a high-strength yarn made from multiple staple fibers that are stretch-broken and formed into a single-strand or plied yarn. These yarns have uniform diameter and high strength. The textile article made from these yarns has better smoothness and comfort. The ratio of staple fibers to total staple fibers is equal to or greater than 60%, and the weight distribution is equal to or less than 60%. The method of making the yarns involves stretch-breaking staple fibers from multi-filaments and controlling the breaking to achieve uniformity in diameter and strength.

Problems solved by technology

These yarns spun from discontinuous staple fibers necessarily have poorer properties than continuous multi-filaments of the same diameter and the same material, including strength and diameter uniformity because of discontinuous staple fiber distribution.

However, a 350D single-strand of Kevlar® multi-filaments is very expensive.

In commercial applications, such expensive yarn is rarely used to make textiles.

Firstly, under a fixed yarn length, because the length of the broken fibers is not uniform, the fiber length distribution in the yarns will have a degree of dispersion.

Larger dispersion of the fiber length distribution in the yarn means that the fiber length uniformity in the single-strand yarn is worse.

The worse the fiber length uniformity is, the worse the cohesive force between the fibers will be.

And, the worse the cohesion force will seriously affect the stress transmission to result in poorer strength uniformity.

Secondly, under a fixed setup fiber length, the weight distribution of the average length of the single-strand yarn will also have a degree of dispersion.

It is mainly because there are too many free fibers.

This free migration of the free fibers is uncontrollable, so it will result in uneven yarn, neps or knots during the spinning process.

The formation of uneven yarn, neps and knots seriously affects the diameter uniformity of the yarn.

In addition, in traditional spinning technology, due to the efficiency requirements of quality control sampling, the weight distribution of the average length of the yarn and the length distribution of the staple fibers are both too long in the sampling length of the test.

But, for yarns that have only undergone stretch-breaking process, drawing process and spinning process with high dispersions, too long sampling length will conceal the problem of dispersions and fail to show the true strength and diameter uniformity of the yarn, and eventually will lead to a large gap between the statistical value and the actual application.

Because high-performance fibers are costly in the production of small-diameter multi-filaments, the relatively low-cost large-diameter multi-filaments of such high-performance fiber can be used to be spun into finer yarn of staple fibers of such high-performance fiber through stretch-break spinning.

However, if the length of the stretch-broken staple fibers is too short, the strength loss of the yarn spun from the stretch-broken staple fibers will increase.

However, judging by the theory of yarn strength uniformity, the average length of the stretch-broken fibers is not a key factor affecting the strength of the yarn spun from the stretch-broken fibers.

Because stretch-break spinning technology of the prior art has poor control over the dispersion of the fiber length distribution in the yarn, the use of a stretch-break spinning technology, disclosed by U.S. Pat. No. 482,563 to make the yarns of the stretch-broken carbon fibers and to control the average length of the stretch-broken carbon fibers, cannot ensure the strength of the yarns of carbon fibers.

In addition, with regard to textile articles made from high-performance fibers using the stretch-break spinning technology to form yarns and then woven, due to the problem of yarn diameter uniformity, the smoothness of the textile articles will be seriously affected, which will cause problems in their use.

It is conceivable that if yarns with uneven finesses are knitted into a knitted fabric, the uneven finesses of the yarns themselves will cause irregular undulations on the surface of the knitted fabric.