JPS605687B2 - Manufacturing method of fused yarn - Google Patents

Description

[Detailed description of the invention] Technical field of the present invention The present invention relates to a method for manufacturing fused yarn.

More specifically, the present invention relates to a method for producing a fused yarn having both a crisp feel and bulk by subjecting a highly oriented undrawn yarn made of polyethylene terephthalate fibers to a stretching and false twisting process.

B. Prior art and its problems Conventionally, as a method for producing fused processed yarn, a method is known in which false twisting is performed while the single yarns are fused together in a high-temperature castle near the melting point, but in this method, Since false twisting is generally carried out at high temperatures, the thermal deterioration of the fibers is significant, and there are drawbacks such as the inability to perform stable processing or the need to process under relatively narrow constraints.

Furthermore, a method is known in which pre-combustion is carried out by supplying a plurality of yarns with different physical properties, or a method is carried out while supplying an excess of at least one yarn among a plurality of yarns of the same type. However, in both cases, there were many disadvantages such as complicated processing due to the supply of multiple yarns and increased cost of raw yarn.

These conventional techniques not only have operational problems as described above, but also have the following common quality problems.
In other words, when welding to a degree that gives a crisp feel,
The bulkiness is markedly reduced, making it difficult to satisfy both conditions, and the degree of fusion in the longitudinal direction of the yarn tends to vary, and when such processed yarn is used to make cloth, the surface of the fabric becomes rough, and Alternatively, only products of extremely poor quality could be obtained, such as those with different dyeing.

C. Purpose of the Invention The present invention solves the drawbacks of the conventional methods as described above, and produces a new fused processed yarn that has both characteristics of crispness, bulkiness, and elasticity with stable workability. The purpose is to provide a method to do so.

D. Structure of the present invention In order to achieve the above object, the present invention has the following configuration.

'1) When applying simultaneous drawing and false twisting to undrawn yarn made of polyethylene terephthalate fibers with a birefringence △n of 15 x 10-3 or more, twisting is stopped on the downstream side of the heater and upstream of the false twisting device. A guide is provided so that the number of twists that spread inside the heater is 30 to 90% of the number of twists applied by the false twisting device.
The ratio of yarn tension on the downstream side of the guide to yarn tension on the upstream side is 1.2 to 1.
4.0, the fibers are further stretched and false-twisted to form a crimped yarn in a temperature range in which the fibers do not fuse, and then subjected to fusion heat treatment using a second-stage heater.
The method of the present invention will be explained in more detail. First, the present invention actively increases the drawing difference between each single yarn of the fiber east due to the twisting action at the drawing point in the simultaneous drawing and false twisting process, thereby reducing the thermal property difference and yarn length difference in the cross-sectional direction of the fiber east. By using the first means of causing a difference in melting point between the constituent single yarns and the difference in thermal properties of the constituent single yarns of the processed yarn intermediately obtained by the first means, low A second means of heat-treating the single yarn in the melting point portion at a temperature range higher than the melting point of the single yarn so that the yarn as a whole has a structure in which the fused portion and the portion having a winding pattern are integrated. It consists of Such welding is performed at a temperature that causes the welding to concentrate partially or completely in the longitudinal direction or cross-sectional direction of the yarn. In other words, when undrawn yarns of thermoplastic synthetic fibers such as polyester fibers are generally fed to a drawing and false-twisting machine and subjected to simultaneous drawing and false-twisting, the drawing behavior of each single yarn in the fiber east depends on the position in the cross-sectional direction of the fiber east. By being heated, the single yarns located at the outer periphery are subjected to a high-magnification stretching action, while the single yarns located at the center are conversely subjected to a low-magnification stretching action. It turns out. The high-magnification drawn part is thermally stable, but the low-magnification drawn part has a low softening point, so by heat-treating it at the same heater temperature, the center of the fiber is fused and concentrated, and each part of the outer periphery is The single yarn is unraveled while being given a winding direction, and a processed yarn having a structure in which the yarn is arranged so as to wrap around the center part is obtained. The important points in the method for producing fused processed yarn of the present invention using these two means are as follows: Regarding the first means, the drawing point in the simultaneous drawing and false twisting process is determined by the heater temperature, tension, and number of twists. It is determined as the distance from the inlet, and it is important to set processing conditions so that the distance from the heater inlet to the drawing point is large in order to fully demonstrate the effect of providing the aforementioned thermal property difference between single yarns. It is.

That is, the yarn temperature at the drawing point is made high enough to provide the above-mentioned difference in thermal properties.
This effect can be achieved extremely effectively by providing a twisting guide downstream of the heater and upstream of the false twisting device, and by creating appropriate contact between the guide and the running yarn to provide running resistance and turning resistance to the running yarn. It is something. In the method for producing fused processed yarn of the present invention, by using the guide as described above, it is possible to actively cause poor migration of the constituent filaments and set the yarn temperature at a high drawing point. However, this guide further includes a specific percentage of the number of twists imparted by the false twisting device in order to obtain a fused yarn that effectively has the characteristics of both bulk, elasticity, and crispness. It is important to have the effect of causing only the number of twists to spread into the heater.

In other words, from the perspective of imparting crimp, the number of false twists is generally determined in accordance with the yarn denier, but it is also important for the present invention to reduce the number of twists that spread into the heater. From the above-mentioned effect, the number of lacquers that spread into the heater is 3 times the number of lacquers applied by the false-twisting lacquer device.
It is necessary to set it to 0-90%.

If the number of twists that spread into the heater is too small, the Kato effect at the stretching point will decrease, resulting in only a simple stretching effect.
On the other hand, if the amount is too large, the migration effect of the constituent filaments will be poor, and there will be almost no difference in drawing of each single yarn in the cross-sectional direction of the fiber east, so that a yarn with the above-mentioned structure cannot be obtained. In the present invention, the number of twists imparted by the pre-twisting device is the number of twists normally used by those skilled in the art for false twisting. On the other hand, the tension during false twisting is generally 0.1 to 0 in order to maintain a stable twisted state.
．． A twisting tension of 3/d is adopted, but the tension immediately before the upstream side of the twisting device is particularly important, and as in the present invention, the tension is considerably reduced on the upstream side of the guide provided downstream of the heater. There is no problem.

Rather, a decrease in yarn tension on the upstream side of the guide increases the distance from the heater inlet to the drawing point, which increases the yarn temperature at the drawing point, which is preferable in the method for producing fused processed yarn of the present invention. That's true. Therefore, regarding the upstream tension and downstream tension of the guide, in the method of the present invention, from the viewpoint of processing stability and the desired effect of the present invention, the tension on the downstream side of the guide provided on the downstream side of the heater / the tension on the upstream side The tension value is 1.2 to 4.
It is necessary to perform false twisting at the same time as stretching so that the tension becomes 0. In this way, the tension of the yarn is increased in the vicinity of the false twisting/twisting device, so ballooning and the like will not occur and yarn breakage will be reduced.

Note that the tension range on the downstream side/upstream side can be set to 1.2 to 4.0 by using a fixed guide. In the method of the present invention, by the above-described first means, a crimped yarn is obtained in which the constituent single yarns have differences in thermal properties when viewed in the cross-sectional direction. Next, regarding the second means of the present invention, the difference in thermal properties of each single yarn in the cross-sectional direction of the fiber east obtained by the first means is utilized to impart a crisp feel while maintaining bulkiness. be.

That is, the single yarn located at the center has a low melting point because it has been drawn at a low ratio, whereas the single yarn located at the outer periphery has a high melting point because it has been drawn at a high ratio, and has a high degree of stripedness. By heat-treating such fibers at a temperature higher than the melting point of the single yarn in the center, the crimped form on the outer periphery remains and the yarn as a whole has a structure in which both are integrated. A fused processed yarn is obtained. Regarding the second method, the crimped yarn obtained by the first method may be continuously processed without being wound up, or the crimped yarn obtained by the first method may be wound into a package and then subjected to post-processing. You can also do this. Note that it is possible to produce a fused yarn similar to the yarn obtained in the present invention by using only the first method.
In this method, the temperature of the heater is set to a high temperature at which the single yarn in the center fuses, and false twisting must be carried out at the same time as drawing. It is not preferred because it is difficult to process or is subject to conditional restrictions such as the number of false twists and tension.

In the present invention, it is preferable to provide a fluid jet exchange process between the first means and the second means.

In the fluid injection entangling process, a fluid such as compressed air is injected onto the pre-combusted filament yarn to entangle the constituent filaments with each other, so that the yarn is bundled and integrated. Furthermore, since the low-stretch portion of the inner layer and the high-stretch crimped portion of the outer layer are interchanged, the inner layer and the outer layer are made uniform. Therefore, if heat treatment is performed for fusing using the second stage heater in this state, the fused portion and the crimped portion will become a mixture, which not only improves the binding integrity but also makes the resulting yarn even crisper. It has a quality difference in that it is rich in In the method of the present invention described above, in order to obtain a stable and excellent fused processed yarn, an undrawn yarn made of polyethylene terephthalate fiber and having a birefringence Δn of 15 × 10-3 or more is used as the supplied yarn. .

Further, to explain the method for manufacturing the fused processed yarn of the present invention with reference to the drawings, Figure 1 shows an example of the outline of the process of carrying out the present invention. The above undrawn yarn 1 is supplied and subjected to a false twisting process while being stretched between a feed roller 2 and a stretching roller 6. When the twist imparted by the false twisting twisting device 5 spreads into the first heater 3, the number of twists in the first heater 3 is reduced by the guide 4 provided on the downstream side of the first heater 3. This also reduces the tension of the running yarn within the first heater 3. The number of twists and tension within the first heater are controlled by preventing the twist from spreading into the first heater 3 in accordance with an appropriate contact angle between the guide 4 and the yarn, and by providing running resistance. For example, when there are two guides 4, the contact angle between the yarn and the guide is the sum of the circumferential angles 8, 82 at which each guide makes contact with the yarn, as shown in FIG. In the method of the present invention, the contact angle is most desirably 3000 to 400 degrees, especially when trying to obtain processed yarn with a good balance of crispness and bulkiness. However, even when the contact angle is less than 300° or more than 400°, the effect of the method of the present invention can be sufficiently achieved, and there is no problem in changing these contact angles as appropriate in accordance with desired yarn properties. The material of the guide 4 needs to be heat resistant since it is located near the heater, and it must also have excellent abrasion resistance since the friction caused by the running yarn is large, such as aluminum oxide. There is no problem if the guide material is a commonly used guide material.

Further, the purpose of the present invention can be sufficiently achieved whether the guide is rotating or fixed, but in the case of a rotating guide, the rotation tends to become unstable after long-term use, and the upstream side of the guide Fixed guides are preferable because they have less tension-reducing effect on the sides. Further, in order to effectively set the contact angle, it is more convenient to use a plurality of guides rather than one guide. Next, each single yarn is entangled by passing it through a fluid jet entangling device (not shown), or after it is passed through the second heater 7 without passing through the fluid treatment device.
The single yarn in the center is fused at a higher temperature than the above, passed through a delivery roller 8, and then taken up by a winding device 9 to obtain a fused yarn having both a crisp feel and bulkiness.

E. Effects of the present invention According to the method for manufacturing fused processed yarn of the present invention described above, by making good use of a guide in the conventional drawing false twisting device, it has excellent properties of both crispness and bulkiness.
Moreover, a fused yarn with stable quality can be obtained extremely easily.

In addition, in the method of the present invention, the temperature of the heater (false twisting heater) is low enough to prevent fusing, so there is no difference from normal stretching false twisting, and in terms of quality, the high temperature heat treatment process for fusing is a separate process. Because of this, the shape of the yarn during heat treatment,
For example, it is possible to vary the degree of relaxation, degree of settling, etc., and therefore it is extremely easy to obtain fused yarns having a wide range of properties. Furthermore, in the first aspect of the present invention, it is possible to efficiently obtain a yarn with a two-layer structure in which the inner layer of the yarn is the fused portion and the outer layer is the winding portion,
Further, the second invention has the effect that it is possible to obtain a fused yarn with a uniform mixture of fused portions and crimped portions and a rich crisp feel.

Hereinafter, the structure and effects of the method for producing fused processed yarn of the present invention will be specifically explained based on Examples.

Example 1 An undrawn yarn made of polyethylene terephthalate fiber with a birefringence Δn of 36×10-3 was supplied to a drawing and false-twisting apparatus as schematically shown in FIG. - Processed yarn was obtained by reheat treatment.

Common processing conditions are the following m to [41].

'1} Denier 28 mark - 6 value (Supplied yarn)
[2) Processing speed 200/min
'3- False twist number of twists 210 medium/M
{4' Stretching ratio: 1.5 Other conditions and results are shown in Table 1.

Table 1 As is clear from Table 1, Experiments Nos. 3 to 7 were within the scope of the present invention, so yarns with a clear two-layer structure, with the inner layer being the fused portion and the outer layer being the crimped portion, were obtained, and the fuzz was eliminated. Therefore, it was possible to obtain a yarn with a desirable balance of crispness and bulkiness.

On the other hand, in Experiment No. 1, the second heater temperature was not at a temperature that would cause fusion, so the false twisted yarn did not have a crisp feel.

In Experiment No. 2, the heater internal combustion number was too high, so the yarn did not have a clear two-layer structure and lacked a smooth feel. In experiment number 9, the number of internal combustions in the heater was too low, resulting in insufficient bulkiness and a yarn with a lot of fuzz. Experiment No. 8 was aimed at producing a two-layered yarn using only the first stage heater, but the heater temperature was too high and fluffing occurred frequently. Example 2 Under the conditions of Example 1 and Experiment No. 5, the false twisting process and the second
An interlace nozzle was provided between the heat treatment process using a heater and compressed air of 3.0 k9/cm was injected from the side of the false twisted yarn to perform air entanglement treatment.

The obtained yarn has a uniform mix of the winding part and the fused part,
The yarn had a crisper feel than the yarn of Example 1 and Experiment No. 5. Example 3 Under the conditions of Example 1 and Experiment No. 5, the birefringence Δn was 17×10 as the starting yarn.
-3 undrawn yarn was used and the conditions were the same except that the stretching ratio was 2.2 times.

The obtained yarn was almost the same as in Example 1 and Experiment No. 5. Comparative Example 1 In Example 3, the starting yarn had a birefringence Δn of 13×
Using undrawn yarn of 10-3, the drawing ratio was 2. I conducted an experiment using needle sounds.

As a result, since the birefringence Δn was too small, the strength decreased immediately after contact with the heater, and a uniform processed yarn could not be stably obtained due to occurrence of fuzz, yarn breakage, and unstable tension.

[Brief explanation of drawings]

FIG. 1 is a process schematic diagram showing an example of the method for manufacturing a fused processed yarn of the present invention, and FIG. 2 is an explanatory diagram showing the relationship between the contact angle between the yarn and the guide. 1: Supply yarn, 2: Feed roller, 3: First heater,
4: Guide, 5: Temporary combustion twisting device, 6: Stretching roller, 7:
2nd heater, 8: Delivery loaf, 9: Winding device. Sai "Picture 2"

Claims (1)

[Claims] 1. Birefringence Δ made of polyethylene terephthalate fiber
When performing stretching and simultaneous false twisting on an undrawn yarn with n of 15 x 10^-^3 or more, a twist stopper guide is provided downstream of the heater and upstream of the false twisting device to prevent the twisting from spreading into the heater. The number of twists is 30 to 90 of the number of twists imparted by the false twisting device.
%, and the ratio of yarn tension on the downstream side of the guide to yarn tension on the upstream side is 1.2.
~4.0, and then further stretched and false twisted to form a crimped yarn in a temperature range where the fibers do not fuse, and then subjected to a fusion heat treatment using a second stage heater. . 2. The method for producing a fused processed yarn according to claim 1, wherein the twist guide is a fixed guide. 3. The method for producing a fused processed yarn according to claim 1, characterized in that a fluid injection entangling treatment is performed between the drawing false twisting and the heat treatment using a second stage heater.