JPS6249379B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a woven or knitted fabric with excellent drapability (flexibility). An object of the present invention is to provide a method for producing a polyester woven or knitted fabric that can provide the polyester woven or knitted fabric with drape properties extremely similar to those of silk or rayon. Synthetic fibers, especially synthetic polymer fibers containing polyethylene terephthalate as the main repeating unit (hereinafter referred to as polyester), are widely preferred as materials for clothing because they have various excellent properties, especially wrinkle recovery and wash and wear properties. Unfortunately, it is not even close to silk or rayon in terms of texture and drapability. In view of the above points, the inventors of the present invention have conducted various studies, and have first devised the characteristics of the polyester material and combined these with the finishing process to use yarn with a high shrinkage rate. proposed a method for producing woven fabrics with excellent drape properties (Japanese Patent Application Laid-Open No. 55-93832). In this method, when the boiling water shrinkage rate is 20% or more, the value obtained by dividing the boiling water shrinkage rate (in %) by the elastic modulus (in Kg/ ^mm2 ) after boiling water shrinkage (also referred to as after boiling water treatment) is calculated.
By knitting and weaving a flat yarn containing polyethylene terephthalate as a main repeating unit with a polyethylene terephthalate ratio of 4/100 or more, and shrinking the yarn in a scouring, dyeing, or similar process, the fabric structure can be buckled or knitted. In this case, the synthetic polymer fibers are made by spinning synthetic polymers containing polyethylene terephthalate as the main repeating unit at high speed and having a birefringence index of 0.025 or more. The drawn yarn is drawn at a temperature below the secondary dislocation point to determine the specific gravity.
A low specific gravity drawn yarn of 1.36 or less is used. However, subsequent research has shown that although there are normally no problems when weaving using the above method, in special cases, when the loom is left stopped for a long time, problems can occur where weaving steps are likely to occur. I realized something. Therefore, the inventors of the present invention have further investigated the problem of the above-mentioned weaving steps, particularly from the viewpoint of the physical properties of the material, and as a result, have found a means for solving the problem. Thus, according to the present invention, the boiling water shrinkage rate is 20% or more, the value obtained by dividing the boiling water shrinkage rate (in %) by the elastic modulus after boiling water contraction (in Kg/ ^mm2 ) is 4/100 or more, and in a free state. The natural shrinkage rate when left for 10 hours is
Weaving polyester flat yarn with a content of 0.2% or less and shrinking the yarn during scouring, dyeing, or similar processes to buckle and loosen the fabric structure, giving it a high degree of drape. A method for manufacturing a textile is provided. Note that the above-mentioned "flat yarn" means filament yarn (also called raw silk) that has not been subjected to bulking processing such as crimping. To explain the present invention in more detail, FIG. 1A is a cross-sectional view of a rayon fabric. In the case of rayon, due to its swelling property, when the threads swell with water during scouring and dyeing decrease in volume during drying, the fabric structure is It has a highly flexible structure as it reduces the contact pressure. On the other hand, in the case of polyester fabric, since it does not have such swelling properties, the fabric structure is loose as shown in (b), and has almost no drapability like rayon. Therefore, when producing polyester yarn, the present inventors performed high-speed spinning to create an intermediately oriented (birefringence index of 0.025 or more) undrawn yarn, and then stretched it at a temperature below the secondary dislocation point. A highly shrinkable polyester yarn with a boiling water shrinkage rate of 20% or more is produced, which is then subjected to scouring, dyeing, or similar processes (chemical treatment, etc.) after weaving.
As shown in C, we devised a method of buckling the fabric structure by shrinking the threads and further relaxing it, thereby creating a fabric structure similar to rayon, as shown in D, and imparting high drape properties. That's why. However, when weaving textiles using this method, although there is no problem under normal circumstances, it has been found that if the loom is stopped for a long period of time due to some special circumstances, there may sometimes be a problem where weaving steps occur. FIG. 2 shows the state of the woven fabric at that time, and the arrow A point in the figure is the point where the loom was stopped for a long time, and a weaving stage is generated at this point. Furthermore, it was also found that the weft thread density temporarily increases only in the weaving direction B from this point as a boundary. Of course, it may be possible to make these looms less noticeable if the looms are re-operated and the looms are properly aligned, but this depends on the skill of the person doing the work, and it is not always easy to do so. isn't it. As a result of investigating the cause of this, it was found that this was due to the natural shrinkage of the thread. That is, Fig. 3 shows the state of the warp threads during weaving. To the right of the arrow point A (so-called Orimae), there is a state of interlacing of the latitude and the latitude. However, if the loom is stopped for a long time in this state, the arrow point A will move by d (several mm) to the left, as shown by the arrow A' point in the diagram.
As a result, the distance between the shuttle S and the arrow A' became shorter, and it was found that the next time the loom was restarted, the weave density would temporarily increase and the weave would become a row. Furthermore, we considered why arrow A moves, and found that the yarn used here has an unstable fine structure that produces high drapability.
As shown in FIG. 1, it has an extremely high shrinkage rate (at room temperature) compared to ordinary polyester yarn 2.
Therefore, if the loom is stopped for a long time, it will start shrinking naturally, and in that case, the right side of point A in Figure 3 A is clogged with weft threads and cannot shrink, but the left side is free to shrink. As a result, it was found that the left and right balance was disrupted and point A was pulled several mm to the left. Therefore, as a result of various studies in order to eliminate such inconveniences, we found that while maintaining a high shrinkage rate of boiling water shrinkage of 20% or more for raw yarn, as a guideline, 10%
It has been found that by suppressing the natural shrinkage rate over time to 0.2% or less (preferably 0.1% or less), this can be manufactured without worrying about weaving steps while maintaining high drapability. To give an example of how to make such a raw yarn, first, polyester is spun at high speed to create an intermediately oriented undrawn yarn with a birefringence index of 0.025 or more. In this case, the polyester may be 100% or may contain a so-called third component, and in short, any polyester thread may be used. Next, this is stretched using a stretching machine as shown in FIG. That is, this undrawn to intermediately oriented yarn 1 is stretched to an elongation appropriate for use, for example, about 20 to 40%. In this case, in the case of polyester, it is common practice to sufficiently heat the supply roller 2 to raise the temperature of the undrawn yarn above the secondary dislocation point, and then stretch it with the drawing roller 3 to achieve sufficient crystal orientation in the fibers. However, in the present invention, the yarn is drawn at a low temperature below the secondary dislocation point to make the fine structure unstable (for example, specific gravity is 1.36 or less) and to make it highly drapeable. In this case, the temperature below the secondary dislocation point refers to the temperature of the yarn itself, and the temperature of the supply roller 1 does not necessarily have to be below the secondary dislocation point, but the temperature of the yarn does not necessarily have to be below the secondary dislocation point. The heating (temperature and time) must not be so strong as to exceed the temperature. In general, it is desirable to use the material without heating in terms of texture, but if the stretchability (wrap, thread breakage, etc.) is likely to deteriorate, it may be slightly heated. Even in that case, care must be taken to ensure that the yarn does not exceed the secondary transposition temperature (approximately 70°C or more, which varies depending on the polymer and spinning speed). However, as mentioned above, if the loom is stopped for a long time, weaving steps will easily occur, so when the yarn is drawn at a low temperature and an incomplete structure is formed, instantaneous high temperature heating is applied by the heater 4, and winding is performed. It is preferable to wind it up on the device 5.
In this case, it would be meaningless to set the boiling water shrinkage rate to the yarn's original boiling water shrinkage rate, so it is necessary to suppress only the natural shrinkage at room temperature while minimizing the effect on the boiling water shrinkage rate. It is best to set it instantly. Figure 6 shows birefringence of 0.05.
This is an example showing the relationship between the setting temperature, time, boiling water shrinkage rate of the yarn, and 10-hour natural shrinkage rate when undrawn yarn is stretched at 1.5 times room temperature. , 0.2 required by the present invention
% or less, and if the time is prolonged, the boiling water shrinkage rate will drop below 20%. This relationship differs slightly depending on spinning conditions, stretching ratio, etc., but in general
It is best to set the temperature in 0.1 seconds or less at a temperature of 150℃ or higher. These sets may be heated using either non-contact or contact heating methods, but non-contact heating has the advantage of less damage to the yarn. In addition, since low-temperature drawing is performed during drawing as described above, it is desirable that the undrawn yarn to be spun has an intermediate orientation with a birefringence of 0.025 or more by high-speed spinning, etc. If the birefringence is less than this, then during drawing This is undesirable as it causes spots, laps, etc. In addition, it is desirable to weave the raw yarn made in this way, shrink it by scouring, etc., and to make the fabric buckle, the width should be increased by at least 50% of that of ordinary similar fabrics. It is better to shrink the thread by 10% or more. Also, in finishing setting, it is better not to apply too much tension, and a width of about 0% to 5% is appropriate, and these values may be appropriately selected in accordance with the spirit of the present invention. In this way, according to the method of the present invention, even if the loom is stopped for a long time for some reason, it is possible to make a fabric with high drape without worrying about the weaving stage, so even beginners can engage in production with peace of mind. It is possible. Example A polyethylene terephthalate chip with an intrinsic viscosity of 0.61 is discharged in a molten state from a nozzle with 36 holes, and it is drawn at a drawing speed of 3500 m/min to 115 de/min.
It was wound onto a bobbin as a 36fil intermediately oriented yarn. Further, the birefringence index of this intermediately oriented yarn was 0.041. Next, this intermediately oriented yarn was stretched at a stretching ratio of 1.6 at 100°C.
A drawn yarn A was obtained by drawing with a heated roller. Separately, the intermediate oriented yarn is stretched in the process shown in FIG. 5 with the temperature of the heater 2 and the temperature of the room temperature heater 4 set at 160° C., while varying the heat treatment time to obtain various drawn yarns (B ₁ - B _o ) was obtained. Table 1 shows the physical properties of these drawn yarns.

[Table] Next, Table 3 shows the condition characteristics of each fabric when yarns A to _B5 were woven according to the fabric design shown in Table 2, and the fabrics were scoured and dyed. In addition, during weaving, the process of weaving for 16 hours, then stopping for 8 hours, and restarting was repeated three times. 2nd surface warp density 1.7.2 birds/cm 2 pieces weft density 33 pieces/cm Scouring bath Heat up from 40℃ to 95℃ for 1 hour, width 15% set 180℃ x 30 seconds width 3% dyeing Color 130℃ x 60 minutes Set 160℃ x 30 seconds Width increase 0%

【table】

[Table] As is clear from the above results, boiling water shrinkage ratio/
The higher the modulus of elasticity, the better the drape properties; however, the higher the natural shrinkage rate, the more weaving will occur, so it is desirable to have a material that satisfies both requirements.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a cross section of a woven fabric explaining the manufacturing process of conventional woven fabrics and the woven fabric of the present invention, Fig. 2 is a top view of the woven fabric in a state where weaving steps are generated, and Fig. 3 shows changes before and after the loom stops for a long time. Fig. 4 is a graph showing the relationship between the passage of time and the natural shrinkage rate of the thread, Fig. 5 is a side view showing one embodiment of drawing, and Fig. 6 is a graph showing the relationship between heating temperature, time and the thread It is a graph showing the relationship between boiling water shrinkage rate and natural shrinkage rate. In the figure, 1...undrawn to intermediately oriented yarn, 2
... Supply roller, 3 ... Stretching roller, 4 ...
Heater, 5... Winding device.

Claims (1)

[Scope of Claims] 1. Boiling water shrinkage is 20% or more, the value obtained by dividing the boiling water shrinkage (in %) by the elastic modulus after boiling water shrinkage (in Kg/ ^mm2 ) is 4/100 or more, and in a free state. A polyester flat yarn with a natural shrinkage rate of 0.2% or less when left for 10 hours is woven, and the fabric structure is buckled by shrinking the yarn during scouring, dyeing, or similar processes. - A method for producing a fabric characterized by relaxing it and imparting a high degree of drapability. 2 An undrawn polyester yarn whose polyester flat yarn has a birefringence index of 0.025 or higher is stretched at a temperature below the secondary transition point temperature, and heat treated by contact or non-contact heating at a temperature of 150°C or higher for 0.1 seconds or less. A method for producing a woven fabric according to claim 1, wherein the woven fabric is manufactured by: