JPS62289628A - Production of polyamide crimped yarn - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing polyamide crimped yarn.

(Conventional technology) Conventionally, polyamide fibers have been false-twisted and have appropriate bulkiness and torque, and are mainly used for knitting. , and there are fields that require high bulkiness, and there was a need for improvement. An example of a field that requires a soft texture and high crimpability is when used for tights, leotards, and pantyhose. In this case, the required properties for tights and leotards include a high fit to the body, and a polyamide crimped yarn with a soft texture and no roughness.

(Problems to be Solved by the Invention) The present invention provides a method for producing a polyamide crimped yarn that is more bulky and softer than conventional polyamide crimped yarns.

(Means for Solving the Problems) The present inventors have conducted extensive studies on the relationship between the characteristics of false-twisted yarn and the soft texture with less roughness when used as a layer of tights. It was found that there is a relationship with the unevenness of the surface of the knitted fabric, and that the flat surface of the knitted fabric has less roughness.The unevenness of the knitted fabric is determined by the crimpability and torque of the false twisted yarn. I got the knowledge that rotation is IL.

Threads with low crimpability tend to have a soft texture, but in the case of false-twisted yarns, lowering the crimpability increases the torque of the multi-yarn yarn. When the torque of the multi-yarn increases, the appearance of the knitted fabric tends to become more uneven, and the texture becomes rougher, which is not desirable. On the other hand, in terms of fit, which is one of the characteristics required for tights, high crimpability is required, and increasing the crimpability increases the torque of the single filament, causing unevenness to appear in the knitted fabric and making the texture rough. However, there is a need to obtain a multifilament yarn with high crimpability, a flat knitted fabric surface, and a low torque of a false-twisted crimped yarn or a single filament. As a result of studying this kind of false twisted crimped yarn,
Excellent Karoe yarn for tights can be obtained by processing polyamide fiber obtained under specific spinning conditions with a specific false twist thread. That is, the present invention has a spinning winding speed of 4000
This is a method for producing a crimped yarn in which a polyamide multifilament yarn wound at m/f+ or higher is stretched and simultaneously false-twisted at a temperature of 140 to 210°C and a false twist number of 0.7X or less. (However, D indicates the denier of the multifilament.) In the present invention, a method of performing heat setting at a temperature of 100°C or more and below the false-twisting temperature with an overfeed rate of 30% or more following false twisting is a preferred method for crimping. This is a method of manufacturing thread.

The polyamide fiber used in the present invention is nylon 6 or nylon 66, in which the yarn extruded from a spinneret is directly wound at high speed without using a godet roller, and in both cases, the spinning winding speed is 4000 m/min or more. It is. If the spinning take-up speed is 4QClm/min or less, it is necessary to perform the simultaneous drawing and false twisting process at a high drawing ratio of 1.5 times or more. The strained polyamide wound yarn has high bulkiness, but after knitting the tights, the dyed finished tights product has a rough texture, and the texture of the tights product plate made from the conventional false twisted yarn using drawn yarn is similar to that of the tights product pane. be. This is because the torque of the constituent single filaments is close to that of a conventional crimped yarn obtained by subjecting a drawn yarn to a false twisting process, and the surface of the knitted fabric appears uneven. It is also believed that the fact that the cross section of the processed yarn obtained is flattened is also indicative of the roughness and hardness of the texture. Polyamide fibers with a spinning take-up speed of 4000 m/min or more can be drawn and false-twisted at a draw ratio of 1.50 or less in simultaneous drawing and false-twisting, and preferably the elongation at break of the spun polyamide fibers ( In contrast to 6), setting the draw ratio to less than 1 + (k'') will reduce the torque of the single filament constituting the crimped yarn and reduce the unevenness of the surface of the knitted fabric, making it flat. preferable.

The false twisting temperature in the stretch false twisting process is 14 for nylon 6.
The temperature is preferably 0 to 180°C, and 14°C for nylon 66.
0 to 210°C is preferred.

The purpose of the present invention is to obtain a low-torque yarn with cylindrical stretchability, and the false-twisting process is preferably carried out at a temperature lower than the false-twisting temperature used for drawn yarns of Fii rice. Also, the spinning winding speed is 4000? Polyamide fibers of Fl/min or more have light-minute heat setting properties even if the degree of false twisting is low, and high shrinkability can be obtained, so they are suitable for obtaining low-torque bulky yarns. In conventional drawing systems, when the false twisting temperature is lowered, the torque decreases, but the crimpability also decreases, making it impossible to obtain high-crimp, low-torque yarns. In addition, when drawing and false twisting the spinning winding speed of 4000 m/min or less, the drawing ratio is 1.5 or more.
The crimped yarn subjected to such high stretching and false twisting has high crimpability, but the torque is also high and the texture of the knitted fabric is hard and rough. Also, the spinning winding speed is 4000 m.
When false twisting is applied to a yarn with a draw ratio of less than 1.5 min, streaks occur in the resulting textured yarn, which is an industrial problem. On the other hand, with spinning winding speeds of 4,000 m/min or higher, no dye gLO occurs even when false twisting is performed at a draw ratio of 1+ (□oo) or less, and the level dyeing properties are excellent, resulting in low Suitable for industrially obtaining bulky yarn with high torque.

There is o, -r x (-41111+590)
In the following, the torque of the V-shaped multifilament yarn obtained is large.
The object of the present invention is not achieved because the surface of the fabric becomes uneven, the texture becomes rough, and at the same time the crimpability decreases.

On the other hand, the number of false twists is 1. When IX(,"" +590) or more, /1)-, the resulting crimped yarn has a high crimpability and the fit of the fabric to the body improves, but the torque of the single filament of the crimped yarn improves. The resulting knitted fabric has a rough and hard texture (unfavorable).

Industrially, there are also problems such as the generation of fuzz and an increase in cut threads during processing.

Furthermore, in order to achieve the object of the present invention, following the false twisting process, heat setting is applied for the purpose of reducing only the torque of the textured yarn and retaining the crimpability. It is preferable to produce a crimped yarn with a soft texture and good fit to the body, and the conditions for this heat setting are selected appropriately according to the required characteristics of the tights product, but overfeeding is preferred. The rate of heat treatment is 30% or more, and the heat treatment temperature is
The temperature is preferably 100°C or higher and lower than the false twisting temperature. If the overfeed rate is 30% or more, the bulkiness will be insufficient, if the processing temperature is less than 100°C, the setting property will be insufficient and a large amount of torque will remain, and if the processing temperature is higher than the false-twisting temperature, the torque will decrease but the stiffness will be low. Tights don't fit well.

(Example) The present invention will be explained below with reference to Examples.

Example: After simultaneous stretching and false twisting, the spinning winding speed was 6000 m to give 70 d/24 f, 5""On'z+θooy, 3
False twisting was performed under the conditions shown in Table 1 using a polyamide fiber yarn of 000 m/min and a normal drawn polyamide fiber yarn of 70 d/24 f (both nylon 66).

The results are shown in Table 1.

The yarn torque (multifilament yarn) is determined by applying a load of 0.025 g/d to the crimped yarn and soaking it in hot water (60°C).
1mm when rotating freely in ) and stopped rotating
Indicated by the number of comb twists, in Table 1, large: 100T/M
above, medium: 100 to 80 T/M, small=80 T/M or less.

Regarding torque of single filament, take out one filament from Vii curly yarn, tie the ends of the filament, apply a load of 0.025.9/d, and soak in hot water (60℃).
), and the display is the same as the yarn torque.

In addition, the bulkiness of the knitted fabric is determined by making the processed yarn into a tubular knitted fabric.
Judging the volume feeling by swearing, ◎: Highly bulky, △:
Display as inferior. As for the texture, the roughness and softness of the tube knitted fabric were evaluated in the same way as the bulkiness. ○: Soft without roughness, △: Slightly hard but not rough, ×: Hard with large roughness. indicate.

Regarding the fit [i! Pass your arm through the ground and display ◎: strong tightness, △: weak.

For level dyeing, use acidic dye Lanyl Bril.
Blue (Sumitomo Chemical product) 5% o w f, bath ratio 1:
50, pH 6 at 100° C. for 60 minutes to evaluate the streak level, and indicate as ×: with streaks, ○: without streaks.

As is clear from Table 1, the polyamide crimped yarn obtained by the invention has all the qualities aimed at by the present invention, such as bulkiness, U & ground texture, fit, and level dyeing, compared to that of this example. It was an excellent crimped yarn that met the following criteria.

(Effects of the invention fJL) According to the present invention, processed yarns for tights, processed yarns for leotards, etc. that have high bulkiness, good fit to the body, soft texture, and no roughness come into direct contact with the skin. In addition, it is possible to obtain a polyamide crimped yarn suitable for fields requiring a fit g, and a crimped yarn with unprecedented level dyeing properties can be obtained.

(8 colors below)

Claims (1)

[Claims] A polyamide multifilament yarn wound at a spinning winding speed of 4,000 m/min or more, with a temperature of 140 to 210°C and a false twist number of 0.7 × [(2300/√D) + 590] or more,
A method for producing a polyamide crimped yarn characterized by drawing and simultaneously false-twisting the number of twists below 1.1×[(2300√D)+590] (where D indicates the denier of the multifilament yarn).