JPS58203114A - Preparation of textured yarn - Google Patents

Abstract

PURPOSE:To obtain textured yarns capable of satisfying the improved crimpability and easy setting properties, by spinning a polyethylene terelphthalate type polymer at a high speed, heat-treating the resultant yarns under specific conditions, and false-twisting the heat-treated yarns while drawing the yarns. CONSTITUTION:A fiber-forming polymer having polyethylene telephthalate as main repeatig units is spun at a speed as high as >=2,500m/min, preferably >=3,200m/min, and the resultant yarns are heat-treated at a temperature higher than the crystallization temperature, preferably 100 deg.C or more higher than the second order transition temperature, for 0.02-1.0sec, preferably 0.02-0.5sec, to give >=25% degree of crystallinity. The heat-treated yarns are then false twisted while drawn to give preferably 12-30% elongation of the resultant textures yarns and give the aimed textured yarns.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a processed polyester yarn with good setting properties.

Conventionally, when polyester processed yarn is used in Yokohata sweaters, there has been a setting process. In other words, horizontal sweaters are usually knitted and linked into a product shape and then set using steam, but for polyester, the temperature is as low as normal pressure steam! Since cents were not effective in the field, high-voltage cent equipment was required, and this hindered the expansion of polyester processed yarn into the sweater field. In addition, in order to be able to set polyester processed yarn at a low temperature, we performed the wooly processing at a low temperature as much as possible to make it strong. There is a method to make the cent effect appear even at low mlf, but with this method, the processed yarn itself has not been woolly processed at high temperature (・, so it has only an extremely weak crimp, and the product has no texture. There were drawbacks.

The present invention does not have such limitations, and while it freely imparts strong crimp, the product can be easily processed using normal pressure steam.
The present invention provides a method for producing a processed yarn that has an ILT function.

That is, the present invention utilizes a fiber-forming polymer having polyethylene terephthalate as a main repeating unit.
High-speed spinning is performed at a speed of 1w1 or more, and then heat-treated at a temperature higher than the crystallization temperature for 0.02 to 1.0 seconds to obtain a crystallinity of 25.
After making it more than 10%, it is not stretched and then false twisted.
This is a method for producing processed yarn.

To further explain the present invention in detail, the material used in the present invention is a fiber-forming polymer (minor polyester) containing polyethylene terephthalate as a main repeating unit.
is suitable. This is because, as mentioned above, polyester has good setting properties at high temperatures if it is normally thread-trapped, but it has little effect on setting at low temperatures, and therefore the improvement effect is significant.

Next, the polymer is spun at high speed in order to facilitate crystallization of the filaments in the subsequent heat treatment step. That is, if the spinning speed is low, the orientation will be low during heat treatment at high temperatures, resulting in fusion or softening between the fibers or the fibers in the heat treatment equipment. Therefore, the higher the spinning speed, the better, and a high spinning speed of at least 250011/ml is required. Furthermore, this high-speed spinning increases the number of nuclei that form the basis of crystals, which means that the crystals will grow and crystallize more easily during the next heating process, and from this point of view, it is 3200 @ / au
It is more desirable if it is equal to or larger than i.

Next, the spun yarn is heat treated to crystallize it.

This is to pre-crystallize the molecular structure so that it will not be excessively aligned even if strong heat and tension are applied during the subsequent drawing and false twisting process, and at least 25
It is necessary to crystallize more than 1. If the crystallinity is lower than 25 inches, low temperature centrifugal properties will be impaired when heat setting is applied during false twisting. When the degree of crystallinity is 32% or more, any kind of false twisting can be applied without any problem.Also, in order to achieve this kind of crystallization, high-speed spinning is required to form crystal nuclei. The thread must be heated to a temperature higher than the crystallization temperature.The crystallization temperature depends on the heating time at that time, but it is desirable to set the crystallization temperature to, for example, the secondary dislocation point temperature of the fiber plus 50°C or higher, preferably plus 80°C or higher. In particular, if the secondary dislocation temperature plus 100° C. or more is applied, there will be no problem no matter what kind of processing is performed.

Further, the heat treatment time requires the time required for the fiber to crystallize, and is required to be at least 0.02 seconds or more. However, if it is too long, the fibers will harden and spots will occur during later processing, so the maximum length is 1.0 seconds, and if possible, 0 seconds.
．． The time is preferably 5 seconds or less.

Finally, the filament yarn thus obtained is subjected to temporary combustion, but at this time it is necessary to draw and false twist it. Even if you try to process this in a fixed length or relaxed state, it is difficult to process because the raw yarn itself has already undergone strong crystallization (also, it will become fluffy or break, and if the degree of crystallization is high) On the other hand, when processing the raw yarn while stretching it, the yarn is twisted while being stretched, so it can be processed smoothly.The stretching ratio at this time is the same as the original yarn. It can be determined appropriately according to the elongation, and in general, it is best to set the elongation of the processed yarn to be about 12% to 30 cm. This is a major feature of the method of the present invention.In other words, in the present invention, there is no need to particularly lower the heat treatment temperature to an extremely low temperature, and even yarns processed with a normal false-twisted texture can be used. One of the most amazing features is that it is possible to generate cents simply by spraying steam at a temperature far below 100 degrees Celsius, which is much lower than the temperature used during false value processing.

By taking advantage of this advantage, it becomes possible to make a side-to-side sweater like other fibers (acrylic, wool, etc.) while taking advantage of the excellent crimp bulkiness of conventional polyester processed yarn.

In the present invention, the means for imparting false twist may be freely used, such as a spindle type or a friction type.Also, the processed yarn may be subjected to Shinkai 2 heater processing, and of course, this will result in loss of setting properties. This is true even after dyeing.Also, the material used in the present invention is polyester as mentioned above, but this
The third component may be included in the form of copolymerization or blending.For example, if a cationic dyeable component is added, the product can be dyed with cationic dyes, resulting in the same brightness as above, making it even more suitable for horizontal sweaters. It becomes something new. Furthermore, although the step of heat-treating and crystallizing the high-speed spun yarn may be carried out in a separate step, it is generally effective to heat-treat the yarn continuously by attaching a hot roller to the spinning machine.

Alternatively, as another means, a heat treatment step can be provided before the false twisting process, and the process can be performed continuously with the process. In this case, the heat treatment can be carried out in any of the relaxed, constant length, and tension conditions as long as the desired crystallization can be obtained, but in general, the setting property of the product is better when the heat treatment is performed in the constant length or relaxed state. However, at least active stretching must be avoided during this heat treatment.

As described above, according to the present invention, the trade-off between improved crimping performance and ease of setting of green spaces is eliminated, and while conventional false twisting processing at the same cost and reduction is adopted, A processed yarn with a high setting effect can be provided.

Next, examples of the present invention will be shown.

A polyethylene terephthalate homopolymer with an intrinsic viscosity of 064 was spun at a spinning speed of 3400 kat/tan.
A raw yarn of 78 D@/48 Fit was obtained. 1 tl of this
After heat treatment for 0.3 seconds with 5% relaxation using a plate heater at 0°C to give a crystallinity of 40 degrees, the number of false twists was 2200 t/m using a spindle type false twisting device, and the stretching ratio was 1.25.
Perform wooly processing at 1 cent temperature -210℃, 1
I prayed for processed yarn of 50 De/48Fi. Next, add this 2
After knitting into 14G jersey, the setability was evaluated. To evaluate the centibility, the knitted fabric is stretched 10 degrees with a metal frame and then steamed at 90°C for 10 seconds, the frame is removed and the rate of return is measured. The set rate was defined as 100% if it did not return. As a result, this sample showed a good setability of 92%. The texture was also excellent in the bulkiness and waist repulsion characteristic of processed polyester yarns.

On the other hand, when I made a similar knitted fabric by drawing and false twisting the above-mentioned spun yarn in the usual way without any particular heat treatment, the texture was eroded, but the setability was only 40 cm (as a sweater) The gold frame body set was at an impossible level.Also,
When the temporary combustion temperature is extremely lowered to 120℃, the setting property is 77%.
However, the crimp was weak and the necessary bulkiness could not be obtained.

Example 2 Polyethylene terephthalate obtained by copolymerizing 3 moles of 5-sodium sulfoisophthalic acid at 4200 m/
While high-speed spinning at a speed of
A raw yarn of 1% 82De/24Ft4 was obtained. Next, this was false-twisted using a three-axis 7-layer false-twisting machine at a stretching ratio of -1, 10 and a set temperature of -180°C (75 D
A processed yarn of e/24F%I was obtained. Next, this is package dyed with cationic dye at normal pressure, and then 3 pieces are lined up and made into one.
When the set property of a 4G pique 7 knitted fabric was measured using the same method as above, the knitted fabric had a good set tJ of 94 cm.
The texture of the knitted fabric was sufficiently crimped, giving it a voluminous feel, giving it a high commercial value.

As described above, according to the method of the present invention, products can be set using a simple method such as normal pressure steam while maintaining high crimpability of polyester processed yarn.

Claims (1)

[Claims] (1) 2500m/1IJ1 of fiber-forming polymer whose main repeating unit is polyethylene terephthalate
High-speed spinning is performed at the above-mentioned speed, and the resultant is heat-salted for 0.02 to 1.0 seconds at a temperature higher than the crystallization temperature to achieve a crystallinity of 25 degrees or higher, and then false-twisted without being stretched. A method for producing processed yarn characterized by: