JPH06280113A - Production of polyester filament - Google Patents

Abstract

PURPOSE:To provide a method for stably and inexpensively producing a low shrinkable polyester filament. CONSTITUTION:The characteristic of this method for producing a polyester filament is to draw an undrawn polyester filament 1 at a prescribed temperature in a drawing treatment region D, thermally treat the drawn filament Y with a crape-finishing drawing roller 5 heated at a higher temperature than the drawing temperature, and to subsequently subject the drawn filament to a relaxation treatment set to a relaxation constant (r) of 1-6%.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a polyester filament yarn having a boiling yield of 3% or less.
More specifically, it relates to a manufacturing method for drawing an undrawn yarn in the fiber axis direction of the yarn.

[0002]

2. Description of the Related Art Conventionally, as a method for industrially producing a low shrinkage ratio of a polyester multifilament yarn, there is a method of using a relaxation device composed of a heated drawing roller and a cold relaxation roller. In the method for producing a low shrinkage yarn by the relaxation method, the fibers in a tensioned state derived from a drawing roller (hereinafter simply referred to as a drawing roller) to be heated are not completely heat-set, and a residue generated by drawing is retained. There is distortion. As a means for reducing the residual strain of the fiber as much as possible, or for relaxing the strain, the temperature of the stretching roller is raised, or a loose yarn between the stretching roller and a cold relaxing roller (hereinafter simply referred to as a relaxing roller). There is known a method of relaxing the yarn by lowering the tension of the yarn.

[0003]

In the above-described conventional relaxation method, if the relaxation rate is increased too much in order to reduce the tension of the relaxed yarn, it may be wound around the stretching roller,
The yarns wound on the roller overlap each other, causing so-called disorder of the yarns, making it difficult to draw, and the target low shrinkage yarn cannot be produced efficiently, and low shrinkage is achieved by a method other than this relaxation method. When trying to obtain a yarn, it is extremely inefficient to significantly reduce the processing speed of the yarn or to raise the temperature of the drawing roller to a very high temperature in order to further enhance the heat setting of the fiber under extremely high tension. Since it is only possible to adopt a method that tends to cause yarn breakage and troubles in the device for raising the temperature, it was not possible to manufacture at low cost. Therefore,
There was a limit to the low cost production of low shrinkage yarns with a boiling yield of 3% or less.

The object of the present invention is to remedy the above-mentioned drawbacks of the prior art, and in the production of low shrinkage yarns, polyester filament yarns for stably and inexpensively obtaining low shrinkage yarns with a boiling yield of 3% or less. The present invention provides a method for manufacturing the same.

[0005]

In order to achieve the above-mentioned object, the present invention basically adopts the technical constitution as described below. That is, when producing a polyester filament stretched yarn, a polyester filament unstretched yarn is stretched at a predetermined temperature in a stretch treatment region to obtain a stretched yarn, and the stretched yarn is heated to a temperature higher than the stretching temperature. Heat treatment using a satin finish drawing roller set to, and then the relaxation rate r of the drawn yarn is 1 to
It is a method for producing a polyester filament which is subjected to a relaxation treatment set to 6%.

[0006]

Since the present invention has the above-mentioned technical constitution, the polyester multifilament unstretched yarn is stretched at a stretching temperature of 80 to 90 ° C, and then in a temperature range of 120 to 155 ° C. Low shrinkage with a boiling yield of 3% or less, which was not obtained by the conventional method, by heating with a stretching roller having a satin finished surface and subsequently relaxing it with a relaxation rate r of 1 to 6% between the stretching roller and the relaxation roller. A low-shrinkage polyester filament yarn that does not cause unevenness in the fineness or strength of the polyester filament yarn and can establish stable yarn running, and as a result, exhibits high yield without the occurrence of yarn breakage or other troubles. You can get it.

[0007]

EXAMPLES Specific examples of the method for producing a polyester filament according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a diagram showing the configuration of a specific example of a stretching treatment apparatus for carrying out the method for producing a polyester filament according to the present invention. In FIG. 1, 1 is an undrawn yarn wound on a drum, 2 is a guide for regulating an undrawn yarn unwinding balloon, 3 is a supply roller, 4 is a heating roller, 5 is a drawing roller whose surface is satin finished, and 6 is It is a relaxing roller that does not heat. As for the roughness of the matte surface of the stretching roller 5, it is preferable that the maximum height (Rmax) is about 2 to 8S and the center line average roughness (Ra) is about 0.5 to 2.5a.

The undrawn yarn 1 unwound from the drum passes through the unwound balloon regulating guide 2 and is then guided to the heating roller 4 by the supply roller 3. Therefore, the undrawn yarn 1 sufficiently preheated at a temperature of 80 to 90 ° C. is drawn 1.3 to 3 times with the drawing roller 5 whose surface is satin finished, and then 120 to 155 ° C. at the same time. Preferably 120-15
Heat treatment is carried out at a temperature of 0 ° C. Then relax roller 6
The yarn is relaxed at a relaxation rate of 6% or less, preferably 3 to 5%, and wound on the bobbin 7.

As will be described later, if the heat treatment temperature of the drawing roller 5 is lower than 120 ° C., a satisfactory low boiling point yarn cannot be obtained. On the other hand, if the temperature exceeds 155 ° C., the unevenness of the thickness in the longitudinal direction of the yarn becomes non-uniform and the strength of the yarn decreases, so that a multifilament yarn of stable quality cannot be obtained.

As exemplified above, in the present invention, the undrawn polyester yarn is drawn to have a low shrinkage (boiling point).
And a multifilament yarn may be used as the polyester filament. The shrinkage ratio in the present invention is a value measured by a boiling yield measuring method according to the JIS method.

The polyester in the present invention is intended mainly for polyethylene terephthalate, but may be, for example, a copolymerized polyester containing ethylene terephthalate units in an amount of 85 mol% or more, preferably 95 mol% or more. Alternatively, the polyester of the present invention may be blended with a small amount of another polymer.

In the present invention, the above polyester is spun as an unstretched yarn which is a raw yarn, and the birefringence obtained at high speed is 0.
It is preferable to use 015 to 0.05 of undrawn yarn,
It is more preferable to use an unstretched film having a birefringence of 0.025 to 0.05. The thickness of the unstretched yarn is not particularly limited, but the thickness when stretched is preferably 10 to 400 denier, and the number of filaments is not particularly limited, either.
Preferably ~ 160 filaments.

In the present invention, the above polyester undrawn yarn is preheated by the heating roller 4 and then heat-treated at a temperature higher than the heating temperature at the time of preheating at the same time as or after the drawing treatment. is there. That is, specifically, when the undrawn yarn is drawn,
The drawing temperature for the undrawn yarn is 80 ° C to 90 ° C, and the heat treatment temperature during the heat treatment for the drawn yarn is 120 ° C.
It is a method for producing a polyester filament having a temperature of ˜155 ° C. In the present invention, the stretching treatment and the heat treatment may be performed in the same treatment area or may be performed in different treatment areas that are sequentially arranged. That is, in FIG. 1, the undrawn yarn 1 is drawn between the heating roller 4 and the heat treatment drawing roller 5 for matte finish to form a drawn yarn Y by a predetermined draw ratio. With the stretching roller 5 and the area D between both rollers 4 and 5,
A drawn region is formed, so that the undrawn yarn 1 is subjected to preheating-drawing-reheat treatment operations in one area sequentially or simultaneously, but the above operations are carried out in individual steps. You can do it as well. In the present invention, the stretching process may be performed in multiple stages.

Next, the drawn yarn Y which has been heat-treated by the satin drawing roller 5 is subjected to a predetermined relaxation treatment in the relaxation region S formed by the drawing roller 5 and the relaxation roller 6, and the relaxation thereof is performed. The rate r is preferably 1 to 6%. Here, the relaxation rate r [%] used in the present invention is determined by setting the peripheral speed of the stretching roller 5 to Ve [m / mi].
n] and the peripheral speed of the relaxing roller 6 is Vs [m / min], the following equation is given.

R = [(Ve / Vs) −1] × 100 [%] In the present invention, the surface of the stretching roller 5 is satin finished, but if the surface is mirror finished, the relaxation rate is 1% or more. Then, the yarn is easily wound around the stretching roller 5, and the yarn between the next relaxing roller 6 becomes unstable,
The yarn cannot be supplied in a stable state. Further, when the surface of the drawing roller 5 is mirror-finished, the frictional force between the yarn and the roller becomes high, and single yarn winding due to single yarn breakage easily occurs at the yarn inlet and outlet of the drawing roller 5, and as a result, Yield is reduced. Therefore, it is preferable that the entire surface of the drawing roller 5 that comes into contact with the yarn has a satin finish. The stretching roller 5 and the separation roller 5 '
The number of windings of the thread around the pair of rollers is such that the thread does not slip, preferably 3 or more, more preferably 4 to 10 times.

Next, if the relaxation rate between the drawing roller 5 and the relaxation roller 6 is less than 1%, residual strain remains in the running yarn between the drawing roller 5 and the relaxation roller 6 and the shrinkage rate of the thread increases. The heat treatment temperature needs to be extremely high.
Therefore, quality deterioration and device trouble are likely to occur.
On the contrary, when the relaxation rate exceeds 6%, the running of the yarn between the stretching roller 5 and the relaxing roller 6 becomes unstable, and the yarn cannot be stably supplied. Therefore, as in the present invention, a heat treatment is performed by the stretching roller 5 having a matte finish on the entire surface in contact with the yarn, the crystallization is sufficiently enhanced, and then the yarn is relaxed between the loosening roller 6 and the yield. It is possible to obtain the shrinkable yarn with stable quality.

The present invention will be specifically described with reference to the following examples. Polyethylene terephthalate having an intrinsic viscosity [η] = 0.65 was melt-spun at a spinning temperature of 290 ° C. through a spinneret having a number of holes of 48 at a discharge rate of 340 D with a drawn yarn and wound at 3070 m / min. This undrawn yarn 1
It was drawn at a drawing speed of 80 m / min to obtain a drawn yarn Y of 340D-48 filaments.

At this time, the surface finish of the drawing roller 5, the temperature of the drawing roller 5, the yarn running property, the yarn physical properties and the yield of the product yarn when the relaxation rate r between the drawing roller 5 and the relaxation roller 6 is changed. Is shown in Table 1.

In Table 1, Nos. 10 to 13 and 16 to 1
8 is an example, and Nos. 1 to 9, 14, 15, and 19 are comparative examples.

As can be seen from the results in Table 1, when the surface of the stretching roller 5 is a mirror surface, the relaxation rate is + 3.7%.
In (No1), the yarn running between the stretching roller and the loosening roller becomes unstable and the yarn cannot be stably supplied,
It was not possible to wind the product thread. In addition, the stretching roller 5
When the relaxation rate is -0.34% (No2 to 7) in order to stabilize the yarn running, the heat treatment temperature is higher than that in the satin finish in order to obtain the target low shrinkage yarn. It is necessary to. At the same time, single yarn winding due to single yarn breakage easily occurred at the inlet and outlet of the yarn to the drawing roller, and the yield could not be 99% or more.

On the other hand, even if the surface of the stretching roller 5 is satin finished, if the heat treatment temperature is out of the range of 120 to 155 ° C. (No. 8, 9, 14), the target shrinkage cannot be obtained if the temperature is low. At 160 ° C, the strength of the yarn decreased.
When the relaxation rate is out of the range of 1 to less than 6% (No15,
In the case of 19), when the relaxation rate is less than 0%, the target shrinkage rate cannot be obtained. On the contrary, when the relaxation rate is 8%, the yarn tension between the stretching roller and the relaxation roller is extremely reduced, the yarn path becomes unstable, and the yarn is stably supplied. Therefore, it was impossible to wind the product.

In comparison with the comparative example, the example is suitable for the conditions to stabilize the yarn running and to produce a low shrinkage yarn with a yield of 99.
%, It was possible to manufacture efficiently.

[0023]

[Table 1]

[0024]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, a low shrinkage polyester multifilament yarn having a boiling yield of 3% or less, which was not obtained by the prior art, is obtained by drawing under the conditions of the range specified in the present invention. It has become possible to manufacture stably at a high rate of at least%.

[Brief description of drawings]

FIG. 1 is a schematic view of a stretching device showing one specific example for carrying out the method for producing a polyester filament according to the present invention.

[Explanation of symbols]

 1 ... Undrawn yarn 2 ... Guide 3 ... Supply roller 4 ... Heating roller 5 ... Heat treatment drawing roller 6 ... Relaxation roller 4 ', 5', 6 '... Separation roller 7 ... Bobbin

Claims (5)

[Claims] 1. When producing a polyester filament stretched yarn, a polyester filament unstretched yarn is stretched at a predetermined temperature in a stretch treatment region to obtain a stretched yarn, and the stretched yarn is heated at a temperature higher than the stretching temperature. A method for producing a polyester filament, which comprises heat-treating using a satin finish drawing roller set to a high temperature, and then subjecting the drawn yarn to a relaxation treatment in which a relaxation rate r is set to 1 to 6%. 2. When the undrawn yarn is drawn, the drawing temperature for the undrawn yarn is 80 ° C. to 90 ° C., and the heat treatment temperature for the drawn yarn is 120.
C. to 155.degree. C. The method for producing a polyester filament according to claim 1, wherein 3. The stretching process and the heat treatment are carried out in the same processing region.
Or the method for producing a polyester filament according to 2. 4. The method for producing a polyester filament according to claim 1, wherein the stretching treatment and the heat treatment are respectively performed in different treatment areas which are sequentially arranged. 5. The method for producing a polyester filament according to claim 1, wherein the stretching process is performed in multiple stages.