CS251172B1 - A method for producing spectacular yarns comprising cotton fibers - Google Patents

Abstract

The solution relates to a method for producing fancy yarns containing cotton fibers, which consists in combing single yarns of different material composition and treating them with sodium hydroxide solutions of 200 to 500vg.l~I. At least one of the single yarns is cotton or a mixture containing at least 85% cotton, and at least one of the single yarns contains at least 50% polyester, polypropylene or polyacrylonitrile staple. These fancy yarns can be used in knitwear or fabrics.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing fancy yarns comprising cotton fibers for knitting and woven fabrics, which consists in splicing single yarns of different material composition by free twisting and subsequently treating the yarns without tension.

Fancy yarns are still widely used in the textile industry both in the manufacture of fashion knitwear and in the production of fabrics. This group includes yarns with color effects, yarns with structural effects, and combinations of the two previous types.

The process according to the invention makes it possible to simply produce yarns with a structural effect and a combined color and structural effect.

The appearance of yarns obtained by this new technology is reminiscent of yarns that have so far been made by winding, for example, a system of polyester silk cotton yarn. The fancy yarns thus obtained need complicated machinery for their production and their properties in knitting or weaving are relatively poor. Often, the twisted yarn is ripped and the resulting fabric is degraded.

These drawbacks are solved by the yarn production process according to the invention. The resulting relief effect is not only achieved by mechanical action, as is the case with the prior art, but by a combination of meohani and chemical technology.

The principle is to combine two or more single yarns, at least one of the yarns being cotton. A blend of cotton and polyester, polyacrylonitrile or polypropylene fibers is allowed, but the fiber content does not exceed 15%.

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At least one of the single yarns must at the same time be made of the aforementioned synthetic fibers or a blend of these fibers with cotton in such a proportion that the proportion of cotton in the single yarn must not exceed 50% ·

After jumping on a twisting machine with a number of twists of 100 to 500 rpm, the chemical part of the process follows. The yarn must be able to shrink freely. For example, the form of skeins is suitable.

If the yarn is not pre-treated or dyed as simple, it is advisable to carry out pre-treatment, for example, in the above-mentioned skein form.

Subsequently, the yarn is exposed to a sodium hydroxide solution having a concentration of 200-500 g / l at 15-80 ° C. The conditions of operation of this bath must be selected depending on the desired degree of effect, which is due to the precipitation of the cotton component of the system.

The treatment with a sodium hydroxide solution, which produces a reversed relief effect, is followed by washing, neutralization, possibly dyeing and other finishing operations.

Best results are obtained when the cotton component of the system is dyed to a deep shade and the synthetic portion remains uncoloured.

The procedure is illustrated in the following examples.

Example 1

A single 20 tex cotton yarn jumps off with an equally thick yarn of a blend of 6.5% polyester staple and $ 35 cotton. The number of twists is 300 per m. After winding into the skeins, the yarn is spun on a spinning apparatus for 30 minutes in a bath containing ethoxylated nonylphenol 1 gl ^-1 sodium carbonate 3 gl ^-1 .

After washing with water at 50 ° C, the yarn was treated for 10 minutes in a bath of sodium hydroxide, 400 gl ^first

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The yarn is then washed with water at 40 [deg.] C., neutralized with acetic acid and then dyed

Reactive Red No. C.I. 5% conventional dyeing technology including finishing operations.

The resultant fancy yarn consists of a cotton core dyed in a deep red hue, the core being wrapped in a blended yarn containing white polyester fibers.

Example 2

In the same procedure of Example 1, the same yarn number from a blend of 80% polypropylene and 20 $ cotton fibers was used instead of the polyester-cotton blended yarn.

The resulting yarn is almost identical to that of Example 1.

Example 3

Single 30 tex cotton yarn is knocked down with two single 20 tex yarns from a blend of 65% polyester staple and 35% cotton. When twisting, 180 turns per m are chosen. After the skewing, the yarn in the form of skeins is processed in a solution of sodium hydroxide 1

250 g.l ”at 80 ° C for 5 minutes. Washing, neutralization and dyeing with substantive dye followed

Spot Blue C.I. 106 3 conventional technology.

The yarn has a similar appearance as in the previous cases, but the wrapping of the uncoloured mixed yarn is more intense.

Claims (1)

SUBJECT OF THE INVENTION A method for producing fancy yarns containing AAv / hfcbS fibers, characterized in that a yarn formation is twisted with a twist of 50 to 500 twists per m, consisting of at least two single ground floors, one containing at least 85 $ cotton fibers and the other at least one Contains at least 5% of polyester staple fibers, polyacrylonitrile or polypropylene staple fibers, acting under tension for at least 10 seconds at 200-500 g at a temperature of 15 to 80 ° C.