JPS6112941A - Method and apparatus for producing false twisted 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] [Technical Field of the Invention] The present invention provides a method that clearly separates the heating area for raising the temperature of the yarn and the heating area for heat-setting the false twist during false twisting and crimp processing. It also relates to processing technology.

[Prior art and its problems]

As the speed of false twisting and crimp processing has increased, heaters have become longer and longer, 2 to 3 AN, due to the need to ensure the false twisting heat setting time, and processing machines have become extremely large.

This is not only a matter of workability, but also involves physical problems such as an increase in the power consumption of the heater and an expansion of the building space.

In order to solve this problem, a technology to shorten the false twisting time is first needed, but this has not yet been realized as it would require changing the heat transfer properties of thermoplastic synthetic fibers. In contrast, the heat setting time is

Several attempts have been made to reduce the spatial area for heating and prevent the processing machine from becoming larger while maintaining the current heating time of 0.3 to 0.5 seconds. It attempts to use a heating roller for heat fixing2, for example,
This is proposed in Publication No. 9151. Direct fixing of false twist using heating rollers, JP-A-49-11635! It was disclosed in the + issue publication. This method performs preliminary heating using a heating roller. By these methods, the spatial area for false-twisting heat-setting is increased.

It can be shortened from 1/2 to 115.

However, these methods still have major problems in common. As the false twist propagates to the yarn on the heating roller, the frictional force between the surface of the heating roller and the yarn depending on the number of twists changes from moment to moment, and the feeding of the yarn by the heating roller is not always constant. It is a point.

In particular, in the latter example, heating is performed by a friction false twisting device, and changes in yarn feed amount are accompanied by changes in false twist tension, changes in tension induce changes in the number of false twists, and further false twists. 1. Changing the number changes the frictional force between the heating roller and the false twisted yarn again.
A periodic instability phenomenon appears, and untwisted portions of false twisting are very likely to occur.

In addition, according to the method disclosed in JP-A-50-48209, the propagation of false twist into the heating roller is prevented, but the surface temperature of the heating roller is at most 100°C. Although it is expected that the number of twists will increase due to the improvement of the drawing d, which is the aim of Preheating does not contribute at all to shortening the heat setting time of false twisting, and conventionally long heating plates must be used.

[Object of the present invention]

The present invention is known in the art. with heating roller.

In a method and apparatus for thermally fixing false twist by using other heating devices in combination, the number of false twists on the heating roller is varied. In addition to eliminating processing instability and deterioration in textured yarn quality, it also aims to shorten the total heat treatment time required to heat set the false twist.

In addition, heating time is required to raise the temperature in a low twist state.

The purpose is to keep the crimp development rate and stretch characteristics of the false-twisted yarn to the same level as general false-twisted yarn.

[Configuration of the present invention]

(1) In false twisting and crimp processing of thermoplastic synthetic fiber filament yarn. When heating the yarn for false twist heat fixing, one yarn is heated in advance by a preheating roller (A).

Next, in the method of heating with the main heating device (B), a false-twist propagation prevention means is provided in an area including the main heating device (B) and the preheating roller (A), and a false-twist propagation prevention means is provided in front of the false-twist propagation prevention means. . The number of false twists of the yarn on the preheating roller (A) is set within a range that satisfies the following formula, and the temperature of the yarn after leaving the preheating roller (A) is set to -100°C, the melting point of iron-based materials. Keep the temperature higher than that.

A method for producing a false-twisted crimped yarn, which comprises introducing iron to a main heating device (B) to thermally fix the false-twisting.

2500>Tx, /"1i (2) In the false twisting and crimping processing apparatus for thermoplastic synthetic fiber filament yarn, from the upstream side, the preheating row 2 (A), the main heating device (B), the heating device, the take-up roller, and the winding An apparatus for producing a false-twisted crimped yarn, characterized in that the twisting devices are provided in this order, and a false-twist propagation prevention means is provided in a region including the preheating roller (A) and the main heating device (B). .

The first important point in the present invention is to use appropriate false twist propagation prevention means to twist the yarn in a low twist state.

The purpose is to raise the temperature to the normal false-twisting heat setting temperature in a very short time using heating rollers. Namely.

Almost all of the constituent single fibers are brought into contact with the heating roller.

The purpose is to raise the temperature of the entire system in a short time. Appropriate means for preventing the propagation of false twisting is not particularly limited as long as it prevents the propagation of twist from the false-twisting heating device from passing over the propagation preventing means to the yarn supply side; to the means for preventing the spread of the disease.

It is desirable that the strong twist state of the false twist is sufficiently transmitted.

More specifically, a guide 11 is provided between a region including the preheating row 23 and the main heating device 4.

A method of bending the yarn at an acute angle to prevent twist propagation (Figure 2).

Alternatively, a method (FIG. 1) in which a heat-resistant top roller 10 is provided on the preheating roller 3;
The contact portions of the upper yarn path regulating guides 12, 13, and 14 are made at acute angles to regulate the heating start point onto the guides, thereby eliminating variations in the number of twists on the preheating roller and preventing twist propagation toward the front of the guides. Methods such as those shown in FIGS. 3a and 3b are possible. In this,
In order to reliably stop the propagation of false twist with a high number of twists, the most effective method is to use the heat-resistant top roller 10. When using the guide 11 after the preheating roller 6 shown in FIG.
Although the device is simple, the false-twisting heating tension becomes very high, so it is necessary to use yarn with sufficient strength to withstand it. Furthermore, if the contact part of the yarn path regulation guide 12 on the preheating/roller is made at an acute angle as shown in FIG. It is suitable for false twisting of the number of twists and for stretch false twisting where the top of the yarn guide becomes part of the drawing point. Although FIG. 5a shows that the thread contacting part of the thread guide 6 is simply made at an acute angle, as shown in FIG. Even if it is a Noropan guide that is used as a guide, it can be effective.

Regarding the number of twists of the yarn on the preheating roller, it is desirable that the yarn is not twisted. All single fibers are arranged in a flat plane, and the temperature of all single fibers is raised in a short time.

This is because the frictional force with the surface of the preheating roller is high and a stable state is achieved. However, even if it is not necessarily untwisted, if the number of twists T per anion is 2500>Txβ (D is the yarn fineness on the heating roller), the heating torque propagation is insufficient in the system as a whole, and the cross section It can also be made extremely flat and the heating time can be shortened.

The preheating roller used here can be a heating roller with a nichrome wire inside or an induction heating roller, but it is desirable that the temperature can be raised to at least 200°C or more. Furthermore, when using the heat-resistant top roller, it is of course necessary to use a material that can withstand temperatures of 220 to 230°C.

The second important point in the present invention is that while the yarn is guided from the preheating rod (A) to the primary heating device (B),
The thread must maintain at least a melting point of -100°C or higher. When the yarn is supplied to the primary main heating device (B) at a temperature lower than this temperature, the temperature is almost the same as when the temperature is raised from room temperature.

This is because it requires time to raise the temperature. According to the inventors' experiments using 150D polyethylene terephthalate yarn, when the temperature of the main heating device (B) is 225°C, it takes 0.60 seconds to raise the temperature of the yarn from room temperature in the heated state.

It took 0.28 seconds to raise the temperature from 100°C, and 0.18 seconds to raise the temperature from 160°C. In other words, when setting the false twisting temperature in the main heating device (B) to a melting point of about -20 to 50°C, it is necessary to raise the temperature from a melting point of about -100°C or higher. It has no warming effect at all.

The third important point of the present invention is that the heating of the yarn by the preheating roller at a low twist number can be done in an extremely short time. In other words, the heating by the preheating roller is just heating to raise the temperature of the yarn, and stabilizing the internal structure of the yarn in a low twist state, that is, promoting crystallization, is the result of the subsequent false twisting structure. In heat setting, the amount of internal strain and the heat setting effect are reduced, and the bulkiness and elasticity of the resulting false twisted crimped yarn are reduced. Example 1 shows the results of manufacturing a false twisted crimped yarn using the false twisting process shown in FIG. 4 and varying the contact time of the preheating roller. As a comparison, the crimp development power of a yarn processed at 450 m/min using a drawing false twister with a heater length of 2.5 m was shown, but the contact time with the preheating roller was long.

It can be seen that the crimp development power is lower than that of ordinary false twisted yarn. That is, the heating time is within 0.2 seconds.

Desirably, it needs to be within 0.1 seconds.

Main heating device (B) following the preheating roller mentioned above
2 is not particularly limited, such as a normal contact heating heater, a hollow heater, or a steam heater, but needless to say, since the heating time can be shortened, a length of 2A to 1/2 of the conventionally required length is sufficient. be. In addition, if infrared heating or laser heating is used, the effect will be further exhibited.

Further, as a supply system for yarn processed by the method and apparatus of the present invention, for example, a polyethylene terephthalate yarn having a birefringence Δn of 0.130 or less.

When using undrawn or semi-drawn yarn, it is preferable to provide a pre-stretching area and feed the yarn to a pre-heating roller, as shown in FIG. In other words, by performing pre-stretching while heating with a heating pin or heating plate, uneven heating on the pre-heating roller can be prevented, and at the same time, even if the temperature of the pre-heating roller is raised to a high temperature exceeding 200°C, single fibers can be The problem of thermal deterioration does not occur, and processing yarn fuzz can be prevented.

[Effects of the present invention]

As mentioned above, when thermally fixing false twist using a combination of conventional heating rollers and other heating devices.

By suppressing the number of false twists on the preheating roller by using an appropriate false twist propagation prevention means, defects in processed yarn caused by twist fluctuations on the preheating roller are eliminated, and all single fibers come into contact with the preheating roller. As a result, the entire system can be heated to a high temperature in a very short period of time before the internal structure of the fibers has stabilized, and while maintaining that high temperature, it can be guided to other heating means to create a false-twisted state. Heat set the
The total heating time and heating area can be shortened.

This means that the faster the false twisting speed is, the more advantageous it is compared to the conventional heating plate method.
Even if the processing speed is from 1/min to several 1000+n/min, the false twist/hard twist heating length may be a realistic 2 to 6 m.

Furthermore, it is effective in false twisting with a large fineness of 500D or more. In other words, since the fibers are first heated in a non-twisted state, the single fibers that enter the inside of the false-twisted heated yarn are also sufficiently heated and then become a false-twisted, highly twisted structure.
The time required for heat to reach the center of the yarn can be shortened.

Example 1 A 280D-48f polyethylene terephthalate semi-drawn yarn with birefringence Δri=0.041 was false twisted using the process shown in FIG. The false twisting processing conditions were as follows, and the experiment was conducted by varying the number of windings of the preheating roller.

Supply roller speed: 258m/min Preheating roller speed: 438m/min Preheating roller circumference: 0.355m Take-up roller speed: 450m/min Heating plate (main heating device) temperature in prestretching area: 15
0°C Heating plate (main heating device) length Ho in the pre-stretching area,
1 m Preheating roller temperature: 190°C False twisting device: 6-axis circumscribed friction false twisting device (polyurethane disk outer diameter 5.1an) False twisting disk rotation speed: 4500 rpm The processing tension was stable at all levels, No occurrence of untwisted yarn was observed.

The yarns of each level were taken into a small cloth and immersed in hot water at 98°C for 20 minutes, and the bulkiness was compared.The CCT values almost corresponded to each other, and levels 1 to 6 compared with level 7. It was comparable to the normal DTY yarn shown for use. In addition, the t-level parts 4 and 5 are slightly inferior to the DTY yarn of the p comparison, but are practical. Level 6 had a neat coil-like crimp, but the bulkiness was quite low, and the crimp was like a conjugate yarn consisting of two differential shrinkage components. This is because the heating time with the Kei heating roller was too long compared to the heat setting time of false twisting. Levels 9 and 10 are the result of increasing the length of the false twist heat setting heating plate.Of course, the longer it is, the higher the ability to develop crimp, but 2 the heating length is shorter than in the case of normal DTY yarn. Example 2 84D-24r 6 nylon semi-drawn yarn was used in Example 1.
False-twisting was performed using the same process.

However, the heating plate in the pre-stretching area was not used.

Supply roller speed: 250 m/min Heating roller speed: 255 # Take-up roller speed: 500 N Heating roller circumference: 0.555 m I Number of turns: 1' Temperature: 170°C False-twisting fixed heating plate length: 0.8 m False-twisting fixed Heating plate temperature: 185°C False twisting device = 3-axis circumscribed friction false twisting device Rotation speed of false twisting disk: 5000 rpm Contact time to heating roller 0.083 seconds, false twist fixed heating plate contact time 0.16 seconds there were. For comparison.

By normal false twisting method. A drawn false twisted yarn with a false twist heat setting time of 0.5 seconds was knitted on a 27 gauge tube knitting machine, and then treated with hot water for 30 minutes. Despite the short heat treatment time of 2
It has a bulkiness comparable to that of regular yarn.

[Brief explanation of drawings]

1 to 4 are schematic diagrams showing two embodiments of the method of the present invention. 1, 2, and 5 show the entire process, and FIG. 3 shows only the heating roller portion. 1: Supply system package 2: Supply system 3: Preheating roller (A) 4: False twist heat fixing plate (main heating device (B)) 5: Heating device (twister) 6: Take-up roller 7: Winding device 8: Pre-stretching supply roller 9: Pre-stretching heating plate 10: Heat-resistant top roller 11.12.1! l: False twist propagation prevention guide 14: Presser guide

Claims (4)

[Claims] (1) When heating the yarn for false twist heat fixing in the false twisting and crimping process of thermoplastic synthetic fiber filament yarn, the yarn is heated in advance by a preheating roller (A), and then the main heating device ( In the method of heating according to B), in the area including the main heating device (B) and the preheating roller (A),
A false twist propagation prevention means is taken, and the number of false twists of the yarn on the preheating roller (A) before the false twist propagation prevention means is set within a range that satisfies the following formula, and the preheating roller (
The temperature of the yarn after leaving A) is maintained at a temperature higher than the melting point of the yarn -100°C, and the yarn is guided to the main heating device (B) to heat set the false twist. A method for producing false twisted crimped yarn. 2500>T×√D [T: number of false twists per 1 m of yarn on preheating roller (A) D: yarn fineness on preheating roller (A)] (2) The yarn is heated by the heating roller (A) within 0.2 seconds when the number of false twists T per 1 m satisfies 2500>T×√D. A method for producing a false twisted crimped yarn according to claim (1). (3) The method according to claim 1 or (2), characterized in that the supplied thermoplastic synthetic fiber filament yarn is guided to the preheating roller (A) while being stretched. (4) In a false twisting and crimping processing apparatus for thermoplastic synthetic fiber filament yarn, a preheating roller (A), a main heating device (B), a heating device, a take-up roller, and a winding device are installed in this order from the upstream side. An apparatus for producing false-twisted crimped yarn, characterized in that a false-twist propagation prevention means is provided in a region including the preheating roller (A) and the main heating device (B).