JPS6249370B2 - - Google Patents

Description

[Detailed description of the invention] The present invention produces a special curled yarn of high quality and excellent operability by cold-drawing undrawn polyester yarn and then performing temporary twisting under special restrictive conditions while drawing it. It is about the method.

Conventionally, with regard to the method of producing low-strength curly yarn by drawing with a low number of tentative twists and subjecting it to ultra-high-speed twisting processing using undrawn polyester yarn, the number of tentative twists and setting time, which are factors in the twisting process, have been studied. A method for manufacturing special curled yarn has already been proposed in which the cooling time is subjected to temporary twisting under special constraints that greatly exceed the range of conditions adopted for normal curling.

However, ultra-high-speed processing with low temporary twist while drawing undrawn polyester yarn generally results in the occurrence of fuzz, thread breakage, and single fiber breakage during processing.
Problems include insufficient setting, lack of variety in quality due to reduced flexibility in processing conditions, and reduced passability in the knitting and weaving process due to poor bundleability and residual elongation of the curled yarn. In particular, it is difficult to increase the processing/stretching ratio because yarn processability is significantly reduced due to an increase in the tentative twist tension ratio, and it is currently impossible to obtain the desired fabric product.

The present inventors have arrived at the present invention as a result of intensive research to solve such problems, and the method of the present invention is a manufacturing method that can also provide products with a wide variety of novel textures. The gist of this is that a highly oriented polyester undrawn yarn with a birefringence of 15×10 ^-3 to 80×10 ^-3 is first cold-stretched, and then further stretched to a tentative twist number of 17,000/√
Below, heat set time 0.03 to 0.2 seconds, cooling time 0.01
This is a method for producing a special curled yarn that can be achieved by performing a temporary twisting process of two-stage stretching for ~0.1 seconds.

The constituent elements of the present invention will be explained in detail with reference to the drawings. FIG. 1 illustrates an embodiment of the present invention. First, the polyester undrawn yarn 1 is supplied to the cold stretching roller 2, and then cold-stretched between the processing and stretching rollers 3, and then continuously stretched between the processing and stretching rollers 3 and the delivery roller 6. The yarn 1 is twisted by a twisting device 5, set on a hot plate 4, cooled, untwisted, and rolled up from a delivery roller 6 to a pirn 7. During the two-stage drawing, a special twisting process is performed. This is for producing shrunken yarn.

To explain in more detail, first, the undrawn polyester yarn to be supplied ^has a birefringence of 15×10 -3 to 80×, which is smaller than the 180 to 190×10 ⁻³ of normal drawn yarn.
A range of 10 ^-3 is preferred. Of course, undrawn yarns other than polyester yarns such as polyamide yarns, acrylic yarns, etc. may also be used, but from the viewpoint of the effects of the present invention, polyester yarns are suitable. The stretching ratio during the process greatly affects the quality and structure of the special curled yarn, as well as the yarn processability, and also greatly affects the combination with the temporary twist insertion method. First, the magnification of the cold drawing processing area is
If the magnification corresponds to the stretching region of the S-S curve of the yarn 1 at room temperature, it is possible to obtain a silky-like curled yarn exhibiting a relatively uniform yarn appearance.
At magnifications corresponding to the free stretching region, the results are quite different. In other words, it tends to have a core-sheath structure,
The core is dark colored and the single fiber denier is thick and coarsely crimped.
The sheath part is light colored, and the single fiber denier is thin and has a two-layer structure in cross section with fine crimp. In particular, in the twisting type temporary twisting method in which a temporary twist is applied by tying the yarn to a fixed pin one or more times and running the yarn, uneven insertion tends to occur in the longitudinal direction of the yarn, resulting in the number of twists. Areas with a large number of twists are stretched to a large extent and have a light color, while areas with a small number of twists are stretched to a small extent and have a dark color, resulting in a color-difference appearance similar to that of a "scraper". It should be noted that the stretching ratio during the temporary twisting process has a large influence on processability such as temporary twisting tension, unrolling tension, fluffing, thread breakage, etc., so it is preferably within the range of conditions normally used for processing. In addition, by performing fluid entanglement treatment in the joining area during temporary twisting processing, it is possible to improve the temporary twisting tension ratio, fuzz, and thread breakage, improving workability and expanding the range of freedom in processing conditions. It is. As described above, it is possible to obtain a wide variety of yarn qualities depending on the draw ratio and temporary twist insertion method, so it is important to appropriately select the desired yarn quality.

Next, regarding the temporary twist processing conditions, first of all, the temporary twist number is in an extremely small range, and 17000/√ or less is the range of processing conditions that exhibits silky "drape" property, touch, or gloss. Both the heat set time and the cooling time are within extremely short ranges, and the conditions are that the heat set time is 0.03 to 0.2 seconds and the cooling time is 0.01 to 0.1 seconds, which has the effect of accelerating the potential of temporary twist residual torque. Therefore, heat treatment after fabrication has the effect of giving it a lively texture. The heat setting temperature needs to be within a range to obtain a sufficient setting effect, but as with the drawn yarn, it is
The present invention can be completed under conditions of ~250°C. If the temperature is lower than 150°C, the stiffness of the curled yarn after yarn processing decreases, and if it is higher than 250°C, a fusion phenomenon occurs, which is not sufficient to achieve the object of the present invention. The temporary twist insertion method may be a spindle type, friction type, or twisting method, but the latter twisting method is preferable in consideration of ultra-high speed temporary twisting processing with a low number of temporary twists, or variation in yarn quality. is optimal for the present invention.

To explain the characteristics of the special curly curly yarn obtained by the present invention, first, the yarn form is a low-strength curly yarn, with low bulk and elasticity, and has a yarn quality with excellent gloss. When used as a fabric, it exhibits a silky-like texture, with supple drape and luster. However, in the case of a special curled yarn with a two-layer structure in cross section, it has a slightly thick texture and a "shari" feel, and in the case of a special curled yarn with a stretch unevenness in the longitudinal direction, it has a short pitch. It has a so-called smudge-like appearance that shows the light and shade, and the tatsu has an extremely mild "shari" feel and "drape" texture, so the former is suitable for knitted fabrics, and the latter is for woven fabrics. Both are products in the thin fabric field. Therefore, it is appropriate to Furthermore, by performing fluid entanglement treatment,
Interlacing can be formed by alternating S or Z twists partially regularly or irregularly along the longitudinal direction of the yarn, making it possible to make the yarn as a whole highly cohesive, and further improving the texture. Generally, it is possible to emphasize the ``shirari'' feeling and ``drape''. Furthermore, since it has excellent bundling properties, it can pass through subsequent processes, such as knitting and weaving processes, easily.

Next, to specifically explain the present invention using an example, a 50 denier 24 filament of highly oriented polyester undrawn yarn was used, a cold drawing ratio of 1.38 times and a temporary Stretching ratio during twisting: 1.01x, setting temperature: 210°C, setting time: 0.13
Temporary twisting was performed during two-stage stretching at a cooling time of 0.04 seconds and an applied tension of 3.5 g, and the result was a stretching recovery rate of 2.3% and a residual torque twist of 21 T/
We obtained 50cm of Kasuri-like special curly yarn. the thread
When knitted with 32G interlock and dyed, it was possible to obtain a silky, glossy product with a mild "shari" feel, "drape" properties, and "scabbing" effect.

Note Expansion/contraction recovery rate: JIS standard Number of residual twists: The number of times the small load rotates when a small load is hung in the center of a 1m trial length and both ends are pulled together.

[Brief explanation of the drawing]

FIG. 1 illustrates a process outline of an embodiment of the present invention. 1: Highly oriented undrawn yarn, 2: Cold drawing roller,
3: processing and stretching roller, 4: hot plate, 5: twisting device, 6: delivery roller, 7: pirn.

Claims (1)

[Claims] 1. A highly oriented polyester undrawn yarn with a birefringence of 15×10 ^-3 to 80×10 ^-3 is cold-stretched, and then further stretched until the tentative twist number is 17000/√ or less, 1. A method for producing a special curled yarn, which is characterized by performing a temporary twisting process of two-stage drawing under processing conditions of a heat setting time of 0.03 to 0.2 seconds and a cooling time of 0.01 to 0.1 seconds. 2. The special curled yarn according to claim 1, wherein the temporary twisting process is a twisting type temporary twisting in which a temporary twist is imparted by tying the yarn to a fixing pin one or more times and running the yarn. manufacturing method. 3. A method for producing a special curled yarn according to claim 1 or 2, characterized in that a fluid entanglement treatment is performed in a temporary twisting area.