CS202115B1 - Method of manufacturing polyester sewing threads - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to a process for the production of high-shrinkage polyester thread sewing threads.

For the production of polyester sewing threads, either the spun yarn of pre-fixed, low shrinkage pre-fixed fibers is usually used, which is dyed and treated, or, if high-shrinkage fibers are used, this gray spun yarn is pre-dyed and possibly re-dyed, fixed with hot air or steam. The common goal of these processes is to achieve the least ductility of the sewing threads with the least shrinkage. A disadvantage of these known processes is the deterioration of the dyeability of the fixed polyester twisted yarns. The fixation increases the crystalline fraction of the polyester fiber structure, so that the penetration of the disperse dyes is slow and after dyeing an increased proportion of unused dye remains in the bath. A further disadvantage of the described processes is that even small differences in thread temperature and tension during fixation cause a different color intensity during dyeing, which is often manifested by the streaking of the bobbins. In addition, to achieve the desired ductility parameters up to 16 ° / o and shrinkage at 170 ° C below 1%, it is necessary to use double fixation technology (before and after) dyeing), which means high production costs. When using only one fixation before dyeing, a shrinkage of 2 to 4% is achieved at an elongation of up to 16% or an elongation of over 20% at an elongation of 1% / o.

The above drawbacks can be overcome by the use of the production technology according to the invention. According to this process, the high-coiling polyester yarn (8 to 13% at 170 ° C) is precipitated to a certain degree, possibly with coloring at 90 to 130 ° C in a water bath. After dyeing, it is not necessary to carry out a reduction cleaning, which shortens the technological time and saves 10 to 20% by weight of the dye. 10 N. 10 ^-2 . Tex and fixed by hot air at 190 ° C. The actual coloring of the fibers takes place only during fixation, so that it is not necessary to achieve perfect coloring during the previous operation and yet achieve high color stability. the sewing treatment is applied and the patterns are obtained The sewing threads thus produced have a shrinkage of up to 1% at 170 ° C and an elongation of up to 15% in the processing of a gray twisted thread with a shrinkage of 8 to 13 ° / o at 170 ° C with an elongation of up to 13%.

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Example 1

80 tex polyester twisted filament yarn with an elongation at break of 11.8% and a shrinkage of 11.2% at

170 [deg.] C. precipitated to gray shade at 95 [deg.] C. with the transmitter and obtained an elongation value of 17.2% and a shrinkage of 5.9 θ / o. After winding on 7.6 N aluminum drums and fixation 90 min. at 190 ° C an elongation value of 14.5% and a shrinkage value of 0.7% were obtained.

Example 2

The polyester gray yarn as in Example 1 precipitated upon dyeing at 115 ° C to obtain a ductility of 18.9% and a shrinkage of 4.6%. After winding on aluminum drums with tension 7.9 N and fixation 90 min. at 190 ° C an elongation value of 14.2% and a shrinkage of 0.8 ° / o were obtained. Example 3

The polyester gray yarn as in Example 1 precipitated upon dyeing at 130 ° C to obtain a ductility of 23.8% and a shrinkage of 4.0%. After winding on 8.3 N aluminum drums and fixation 90 min. at 190 ° C an elongation value of 14.8% and a shrinkage of 0.9 ° / o were obtained.

Claims (2)

SUBJECT OF THE INVENTION Method for producing polyester sewing thread, characterized in that the polyester gray twisted yarn with shrinkage up to 13% at 170 ° C is precipitated in the first stage at a temperature of 90 to 130 ° C and in the second stage it is wound on fusing drums 10 N. 10 “ ² . tex. 2. Method according to claim 1, characterized in that the precipitation takes place simultaneously with the dyeing of the yarn.