JPH055876U - Polyester fiber drawing equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a drawing apparatus suitable for drawing with high orientation and high strength by improving the defects such as yarn breakage, energy increase, and yarn unevenness of the conventional apparatus. [Structure] Large-diameter roller group 1 controlled to be heated to 60 ° C. or less as a first-stage preheating extension part, and heated to a temperature exceeding 110 ° C. with a diameter of 80 mm or less arranged subsequently to the roller group 1 It is composed of a small-diameter roller group 3 consisting of controlled small-diameter rollers 4, and the undrawn yarn is preheated in the large-diameter roller group 1 at a low temperature while suppressing crystallization, and the deformed portion has a small diameter at a high temperature. Since the rolling is performed by the roller group 3, most of the deformation is completed with low tension, the neck portion can be fixed to the sheep more, and the subsequent draw ratio is improved to enable higher strength.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a stretching device for melt-spun polyester fibers, and is applied to a stretching device for polyester fibers for industrial materials that require high orientation and high strength.

[0002]

[Prior Art]

 Generally, synthetic fibers, particularly polyester represented by polyethylene terephthalate, are fiberized by a melt spinning method.

The typical process is to discharge a polymer melted at a temperature of 280 to 320 ° C. through pores, thin it, cool it, and after taking it down, an undrawn yarn having a low orientation of several hundred%. The spinning process comprises a spinning process and a stretching process in which the film is once wound or directly followed by a single step or multi-step drawing heat treatment of 3 to 6 times.

The stretching device used in the stretching step is usually a heat treatment at the first stage and the second stage and subsequent stages where a deformation accompanied by necking is performed after preheating near the glass transition temperature of the polymer (70 to 90 ° C.). Although it is composed of stretching and high temperature heat treatment, the first-stage stretching part is particularly important as a stretching device for industrial materials that requires high-magnification stretching to impart a high degree of orientation.

That is, in the first-stage stretching, while performing uniform and high-level stretching, the crystallization accompanying the orientation is suppressed, and the subsequent second-stage and subsequent stretching is facilitated. Required to be kept. Ideally, it is desirable to raise only the orientation to completely suppress the crystallization, but it is practically difficult to separate the orientation and the crystallization.

Therefore, various improvements have been made to the stretching apparatus and the stretching method in order to bring this ideal state as close as possible. For example, a method of stretching at a low temperature and a high tension in order to suppress crystallization, a so-called steam jet stretching device that blows an overheated steam to fix the deformed portion in a sharper shape, etc. Is proposed.

However, in the former method, rubbing under high tension and damage of the running yarn due to friction are likely to occur, and yarn breakage occurs during drawing. In the latter method, excessive heating of the steam is required. The increase of the power cost for the operation, the complexity of the steam drain treatment, and the unevenness of the inner and outer layers of the single yarn (particularly the lowering of the orientation of the surface layer at high temperature) are likely to occur.

[0008]

[Problems to be solved by the device]

 The present invention improves the drawbacks such as yarn breakage, energy increase, maintainability and yarn unevenness of the conventional device, and provides a drawing device suitable for drawing with high orientation and high strength.

[0009]

[Means for Solving the Problems]

 That is, the present invention relates to a device for preheating and drawing undrawn polyester yarn, in which a large diameter roller group or roller pair heated to 60 ° C. or less and a yarn exit side subsequent to the roller group are provided. Of a polyester fiber characterized in that a preheating stretched portion formed by connecting a group of rollers having a small diameter heated to a temperature exceeding 110 ° C. arranged in It is a stretching device.

[0010]

【Example】

 Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a schematic side view showing an embodiment of the present invention.

In the figure, reference numeral 1 denotes a large-diameter roller group in which a plurality of large-diameter rollers 2 are arranged, which is controlled by a heating means (not shown), such as circulation heating of a heating medium or dielectric heating. The temperature is maintained at 40 ° C to 60 ° C which is a possible temperature. The large-diameter roller 2 has a diameter considerably larger than that of a small-diameter roller described later, for example, preferably 200 mm to 300 mm or more, but is not limited thereto.

The holding (control) temperature as a heating roller is set to 60 ° C. or lower, but if the heating temperature exceeds 60 ° C., crystallization will occur at the same time during preheating and the subsequent draw ratio will decrease. Further, if the temperature is lower than 40 ° C, it is difficult to control the surface temperature, and the function as a controlled heating roller cannot be achieved. Therefore, temperature unevenness in the longitudinal direction of the yarn is likely to occur and the uniformity is lowered. It is not preferable because

The number of the large-diameter roller group 1 needs to be appropriately selected in relation to the processing speed and the yarn contact length of the large-diameter roller 2, but for example, at a processing speed of 50 to 100 m / min. If the yarn contact angle is about 180 ° as shown in Fig. 1, at least four yarns should be arranged in order to make the preheating more sufficient. Further, in the direct stretching method at a processing speed of 500 to 1000 m / min, a method of winding 10 to 15 times around the roller pair as a Nelson roller pair is adopted in order to make the apparatus compact. Appropriate.

Following the large-diameter roller group 1, a small-diameter roller group 3 consisting of a heat-controlled small-diameter roller 4 having a diameter of 80 mm or less is arranged at the exit side position of the yarn y. Therefore, it is rotated at the same peripheral speed as the large diameter roller 2 or at a peripheral speed to which a press stretch (about 1%) is applied.

The smaller the diameter of the small-diameter roller 4, the better. However, in the normal case, it is preferably 30 to 80 mm, and if it is smaller than this, the rotation of the bearing will be high and the load on the bearing portion will be excessively applied. Since it is difficult to heat the heating medium or steam through conduction, it is practically difficult to employ. On the other hand, if it exceeds 80 mm, it becomes difficult to fix the sharp net.

The heating temperature of the small-diameter roller 4 needs to be a high temperature exceeding 110 ° C. When the temperature is 110 ° C. or lower, the tension at the time of deformation is high, and the deformation zone is wide so that crystallization due to orientation is easily promoted. The high temperature side is limited to a crystallization peak temperature or lower and is usually about 150 ° C., but some differences occur depending on the processing speed, the degree of polymerization of undrawn yarn, and the like.

The number of small-diameter roller groups 3 is preferably 2 to 4, and if the number is less than 2, that is, if the number is one, the temperature rise from a low temperature to a high temperature is insufficient. The same phenomenon is apt to occur, and if the number exceeds four, it is exposed to an excessively high temperature after deformation and the orientation is lowered by relaxation, which is not preferable.

A first stage drawing roller 6 comprising a small diameter roller group 3 and a first stage drawing roller 6 which draws a yarn y heated by a small diameter roller 4 at a speed several times faster. Roller group 5 is provided. The peripheral speed ratio of the first-stage stretching roller group 5 is usually set so as to obtain a magnification difference of 2.5 to 5.0 times. Hereafter, a stretching section capable of appropriately carrying out the stretching heat treatment of the second stage, the third stage or the fourth stage is attached.

As the roller heating means, known heating methods such as heating medium circulation heating, dielectric heating, and direct heating with a high-pressure steam can be appropriately used.

However, by having the first-stage preheating extension part having such a structure, the preheating is carried out in the large diameter roller group at a low temperature as compared with the conventional method, and the neck deformation part is heated to a high temperature. As shown in FIG. 2, crystallization can be suppressed at a low temperature as compared with the conventional method described later (having a conventional heating roller without the small-diameter roller group 3 in FIG. 1) as shown in FIG. By preheating and providing the deformed portion to the high-temperature small-diameter roller group, it is possible to complete most of the deformation with low tension and fix the neck portion to the shoop.

In FIG. 2, A shows the relationship between the first stage draw ratio and the first stage draw tension in the case where a 6000 de polyester undrawn yarn was drawn at a temperature of 80 ° C. only with a conventional heating roller. B is the relationship between the magnification and the tension when the large diameter roller group is drawn at a temperature of 50 ° C and the small diameter roller group is drawn at a temperature of 120 ° C in the apparatus according to the present invention as shown in Fig. 1. Is illustrated.

[0022]

As described above, according to the present invention, since unnecessary crystallization in the first stage is suppressed and a sharp deformation is performed, the stretching ratio in the second stage and thereafter is significantly increased. It is possible to improve the strength by about 10% compared to the conventional method, and it is possible to easily achieve the high strength of polyester fiber and to reduce yarn unevenness, and to obtain a stable product with excellent quality with simple equipment. There is a remarkable effect that it becomes possible.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between the first stage draw ratio and the draw tension.

[Explanation of symbols]

 1 Large diameter roller group 3 Small diameter roller group 5 1st stage drawing roller group

Claims (1)

[Claims for utility model registration] Claims: 1. A device for preheating and stretching unstretched polyester yarns, wherein a roller group or roller pair having a large diameter heated to 60 ° C. or lower and the roller pair. Following the group, a small-diameter roll that was placed on the yarn exit side and was heated to a temperature exceeding 110 ° C.
A polyester fiber stretching device, characterized in that a preheating stretching portion constituted by connecting a group of la is provided at an upstream position of the stretching roller.