JPS6247982B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method of manufacturing a woven or knitted fabric at a low cost, which streamlines the process by forming a woven or knitted fabric from high-speed spun polyester fibers without drawing them and subjecting them to tension heat treatment. In recent years, the international competitiveness of the synthetic fiber industry has declined due to the appreciation of the yen, so radical cost reductions and the development of high value-added products have become essential. The present invention aims at radically reducing the cost of the former. Conventionally, the method of producing woven or knitted fabrics without using processed polyester yarns, that is, crimped yarns, or in other words, using flat yarns, is to melt-spun polyester at a spinning speed of around 1000 m/min, wind it, and undergo glass transition. The material is stretched 3.0 to 4.0 times above the temperature, heat-treated at around 180°C, then wound, knitted, knitted, scoured, dyed, and heat-treated to obtain woven and knitted products. For this reason, a hot stretching process is required in addition to the spinning process, resulting in high costs. In order to omit this separate drawing process, we have developed a method in which the yarn is drawn without being wound once after spinning, then wound and then knitted or woven, or by ultra-high speed spinning at a spinning speed of around 5000 m/min. A method of knitting is known. However, the former method does not reduce costs because it requires a preheating roller for stretching and a heating roller for heat treatment, and the latter method requires a very expensive winding machine. It has not yet been put into practical use because the parts have a short lifespan. As a result of intensive research in view of the above-mentioned problems, the present inventors have found that if a specific undrawn yarn obtained by directly using conventional high-speed spinning equipment is used for weaving and weaving, and then subjected to tension heat treatment, the thermal stability will be improved. The inventors have discovered that a woven or knitted fabric with a good surface can be obtained, and have arrived at the present invention. That is, the present invention uses an undrawn yarn spun at high speed, which is made of polyester having ethylene terephthalate as a main repeating unit and has a structural integrity parameter ε _0.2 of _0.1 to 0.6, and has a yarn tension of 0.2 g/de.
This is a method for producing a polyester-based woven or knitted material, which is characterized by carrying out the following weaving and weaving, and subjecting the obtained woven or knitted material to tension heat treatment at an elongation rate S (%) that satisfies the following formula. 6·ε _{0.2 −6} ≦S(% _{)≦40·ε 0.2 +6} The present invention will be explained in detail below. The polyester fiber used in knitting and weaving in the present invention is an undrawn yarn spun at high speed, which is made of polyester whose main repeating unit is ethylene terephthalate, and has a structural integrity parameter ε _0.2 of 0.1 to _0.6 , preferably 0.2 to 0.5. be. The structural integrity parameter ε _0.2 referred to in the present invention is _defined in U.S. Patent No.
This value was measured according to the method described in Column 4, Lines 39 to 49 of Specification No. 3771307. i.e. 10cm
A load of 0.2 g/de is applied to the filament yarn, and the length l ₀ of the filament yarn at that time is measured. Next, the filament yarn was immersed in boiling water for 2 minutes under a load of 0.2 g/de, then taken out from the boiling water, cooled, and measured for length l ₁ under a load of 0.2 g/de. _The structural integrity parameter ε _0.2 is calculated by the following equation. ε ₀ . ₂ =l ₁ −l ₀ /l ₁ In the present invention, the structural integrity parameter ε ₀ .
It is important to knit and weave using undrawn yarn in which ₂ is within the range of 0.1 to 0.6. An undrawn yarn having a structural integrity parameter ε _0.2 within the above range has good shapeability during tension treatment and less shrinkage that occurs during weaving and weaving _. It can exhibit a good texture without becoming hard. Moreover, since the change in yarn quality over time after spinning is small, the handleability is also good. Here, when using an undrawn yarn with ε _{0 .} Density spots that cause dyeing spots are likely to occur in the subsequent knitting. _On the other hand, when undrawn yarn with ε ₀ . Furthermore, when the resulting textile is subjected to heat treatment, its texture becomes hard. As a method for producing such undrawn yarn with _{ε 0} .
It is preferable to set it to about minutes. In the present invention, when knitting and weaving is carried out using threads within the above range, it is important to maintain the thread tension at 0.2 g/de or less during weaving and weaving. If the yarn tension during weaving exceeds the above range, shrinkage may occur in the woven or knitted fabric. The present invention has _{a structural integrity parameter ε 0.2 of} 0.1 to 0.6.
After knitting and weaving using high-speed spun polyester fiber, it is necessary to subject it to tension heat treatment at an elongation rate S (%) that satisfies the following formula. 6・_{ε0.2 −6} ≦S(%)≦40・_ε0.2 +6 Preferably 6・_{ε0.2 −0.6} ≦S( _% )≦30・_{ε0.2 +3} The above extension rate S(% ), a woven or knitted fabric with good thermal stability, moderate flexibility, and no dyeing or density unevenness can be obtained. If the elongation rate exceeds the above range, dyeing spots and density spots will occur in the woven or knitted fabric, and in extreme cases, the fabric will break. On the other hand, if it is smaller than the above range, the woven or knitted fabric becomes stiff or shrinkage spots occur on the fabric, which is not good. In addition, the temperature during heat treatment of the above woven and knitted materials is 70 to 140℃ with wet heat and 160℃ with dry heat.
Preferably the temperature is ~220°C. If the temperature during heat treatment is less than the above range, thermal stability will deteriorate because sufficient heat treatment is not performed, and conversely, if the temperature during heat treatment exceeds the above range, the flexibility of the woven or knitted fabric will tend to decrease. . As described above, according to the present invention, it has become possible to omit the drawing process, which conventionally required ultra-high-speed spinning using a special ultra-high-speed winder. , it is possible to obtain a woven or knitted fabric that is also highly flexible. Example Polyethylene terephthalate having an intrinsic viscosity of 0.63 in an orthochlorophenol solution at 35°C was spun under the following conditions to obtain a multifilament of 150 de/48 fil. Spinning conditions Spinning cylinder length 2.5m Cooling air Temperature 25℃, room temperature 60%RH Wind speed 30~40cm/sec Draft 100~200 Winding tension 0.4g/de Spinning speed 2900~4200m/min Test using this multifilament The fabric was woven in a twill weave on a small commercial loom under conditions such that the thread tension was 0.2 g/de or less, and then subjected to tension heat treatment at 200°C dry heat with varying elongation rates. The results are shown in the table below.

[Table] As is clear from the above table, it can be seen that the knitted fabrics within the scope of the present invention are excellent in both quality and texture. Comparative Example Experiment No. 6 of the example was carried out in the same manner as in the example except that the yarn tension during weaving was 0.25 g/de. The resulting fabric had shrinkage and was of C fabric.

Claims (1)

[Claims] 1. In producing a polyester woven or knitted fabric,
It is obtained by knitting and weaving at a yarn tension of _0.2 g/de or less using undrawn yarn spun at high speed and made of polyester having ethylene terephthalate as the main repeating unit and having a structural integrity parameter ε _0.2 of 0.1 to 0.6. A method for producing a polyester-based woven or knitted fabric, which comprises subjecting the woven or knitted fabric to tension heat treatment at a stretching rate S (%) that satisfies the following formula. 6・_{ε0.2 −6} ≦S(%)≦40・_{ε0.2 +6} 2 The heat treatment temperature during tension heat treatment is 70 to 140 with moist heat.
℃, 160 to 220℃ in dry heat
A method for producing a polyester woven or knitted material as described in .