JPS6131213B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing polyester fused false twisted yarn. Many methods have been known to obtain twisted yarns with novel textures using polyester, and some methods have been proposed that utilize the creation of fusion between single fibers. For example, a method of performing stretching false twisting using undrawn polyester yarn (described in Japanese Patent Publication No. 51-7216), a method of obtaining a fused yarn by false twisting using partially drawn polyester yarn (described in Japanese Patent Publication No. 11218-1982) ) are known. Generally, in order to produce fusion bonding, it is necessary to strengthen the heat treatment with a heating body compared to normal false twisting. The method of using However, when a high temperature heating element is used, the following problems arise. (1) There is a certain limit to the temperature that can be used (usually below the melting point) because high temperatures may cause thermal deterioration of polyester. Therefore, in order to perform heat treatment sufficiently, there is an upper limit to the speed, and it has been difficult to increase the speed. (2) Furthermore, if a high-temperature heating element is used, there is a problem that the polyester processing agent will undergo thermal deterioration and thermal decomposition during heat treatment, and will also become attached as tar etc. near the yarn path of the heating element. . (3) Using a high-temperature heating element requires a large amount of thermal energy and is also expensive in terms of equipment, which is economically disadvantageous. (4) In general, when using multiple spindles in fused false-twisting, it is necessary to strictly control the temperature of the heating element, but temperature control at high temperatures is more difficult than under normal false-twisting conditions, so sufficient control is required. In order to do this, expensive equipment must be used. As a result of various studies on methods for solving the above problems, the present inventors found that by adding water to the undrawn or partially drawn polyester yarn before supplying it to the heating means, fusion is dramatically promoted. This is what we discovered and arrived at the present invention. That is, the present invention provides an apparatus in which a supply roller, a heating means, a false twisting means, and a stretching roller are provided in this order.
When undrawn polyester yarn or partially drawn yarn is sent in the direction of the heating means by a supply roller and subjected to false twisting while being stretched and causing fusion between single fibers, the yarn enters the heating means after passing through the supply roller. This is a method for producing a fused false twisted yarn, which comprises adding water to the undrawn yarn or partially drawn yarn. The present invention will be specifically explained below. FIG. 1 is a front view of a stretch false twisting device showing an embodiment of the present invention. The undrawn yarn 1 is fed by a supply roller to a false twist hot plate 4 which is a heating means. A water applying device 3 is provided between the supply roller 2 and the false twisting hot plate 4, and applies water to the running yarn after passing the supply roller. Water is applied by the water application device 3, and the undrawn yarn is twisted and stretched on the false-twisting hot plate 4 by the false-twisting device 5, which is a false-twisting means, to cause fusion between the single fibers. .
The yarn in which fusion has occurred between the single fibers is transferred to the drawing roller 6, the second
The yarn passes through a hot plate 7, a yarn feed roller 8, and is wound up by a winder 9. The water application device may be any device that can apply water to the yarn, such as a water-impregnated cloth, a sponge, a rotating roller capable of retaining water on its surface, a water application guide, or the like. Particularly preferred is one that can constantly apply a predetermined amount of water, and it is preferable to use a rotating roller, a water application guide, or the like. As the water application guide, one having the shape shown in FIG. 2 is used.
Water is continuously applied to the running thread 12 at the opening of the water conduit 11 that penetrates the guide body 10, and the material of the guide body 10 may be metal, but it is more preferably ceramic. . Note that it is preferable to connect a metering extrusion device to the water conduit 11 so that the amount of water applied can be controlled. In addition, the moisture content is expressed as the weight fraction of water attached to the thread, and is preferably 2.0% or more, and furthermore, 3.0% in order to promote the fusion between single fibers, which is the objective of the present invention. The above is more preferable. However, if too much water is applied, problems such as a decrease in the heat treatment effect of the yarn due to vaporization heat on the false-twisting hot plate 4 and water scattering between the water applying device 3 and the false-twisting hot plate 4 may occur. Therefore, it is preferable that the moisture content is 12.0% or less. In addition, various processing agents, preservatives, etc. can be mixed into the applied water depending on the purpose as long as it does not impede the effects of the present invention, but it is important to avoid contamination of false-twisting hot plates, false-twisting equipment, etc. From this point of view, it is preferable to reduce the amount of additives as much as possible. The temperature of the false-twisting hot plate, which is the heating means, needs to be at a temperature that can cause fusion between the single fibers, but the temperature of the false-twisting hot plate depends on the type of polymer used and the speed of the yarn. It can be selected as appropriate. By adding water, the temperature of the false-twisting hot plate can be lowered than when fusion is caused between single fibers under the same conditions without adding water.
Furthermore, when processing at the same temperature, processing can be performed at a higher speed than when no water is added. In the present invention, undrawn yarn or partially drawn yarn,
It is not clear why the addition of water promotes fusion when stretching and fusion between single fibers on a heating device, but water probably has the effect of acting as a plasticizer on polyester. It is thought that this is because of this. Note that the second hot plate 7 may or may not be used depending on the purpose. Generally, the torque of false twisted yarn with fusion between single fibers is strong, so the second hot plate 7
It is preferable to reduce the torque by using In the present invention, the polyester polymer constituting the polyester undrawn yarn or partially drawn yarn is made of terephthalic acid or its lower alkyl derivative (diester of an alkanol having 1 to 4 carbon atoms) and ethylene glycol, or terephthalic acid or its lower alkyl derivative (diester of an alkanol having 1 to 4 carbon atoms) and ethylene glycol. Obtained from a lower alkyl derivative and ethylene glycol and at least one other component, or from bis-2-hydroxyethyl terephthalate or a low polymer thereof, or from bis-2-hydroxyethyl terephthalate and at least one other component A polyester polymer in which at least 70% of the polyester units are polyethylene terephthalate. In this case, examples of the third component include aliphatic dicarboxylic acids, isophthalic acids, phthalic acids, aromatic dicarboxylic acids, alicyclic dicarboxylic acids, 5-sodium sulfoisophthalic acid, 5-methylsulfoisophthalic acid, and trimellitic acid. , multipotent compounds such as biromellitic acid diethylene glycol,
Examples include polyoxy compounds such as propylene glycol, polyethylene glycol, and pentaerythritol. Needless to say, neither is limited to these. In addition, pigments such as carbon black, phthalocyanine, and titanium oxide,
Phosphorous compounds such as phosphoric acid, phosphorous acid, triphenyl phosphate, etc. may be added. In addition, if the melt viscosity of the polyester used in the present invention is extremely low, a boron compound,
It is also desirable to add an aluminum compound or the like to maintain a suitable melt viscosity. The term "undrawn yarn" as used in the present invention refers to a yarn obtained by melt-spinning the above-mentioned polyester polymer using a conventional method, and includes everything from low spinning speed undrawn yarn (so-called UY) to high spinning speed end-drawn yarn (so-called POY). do. The term "partially drawn yarn" means a yarn obtained by drawing the above-mentioned undrawn yarn at a draw ratio lower than the draw ratio at which the undrawn yarn is completely drawn (so-called thick-and-thin yarn). As for partial stretching, the generation of fuzz in the false twisted yarn is less when the high spinning speed undrawn yarn is drawn than when the low spinning speed undrawn yarn is drawn, and especially when the birefringence Δn of the undrawn yarn is 15× 10 ^-3 or more is preferable. The device used in the present invention may be any device as long as it is capable of stretching the yarn between a supply roller and a stretching roller, and a general false twisting device can be used. As the false twisting means, devices such as pin twist, friction false twist, and fluid false twist can be used, but a friction false twist device is preferable for high-speed processing. The frictional false twisting device may be either of the external or internal type, and the friction body may be made of rubber, ceramics, metal, or the like. The effects of the present invention are as follows. (1) When performing heat treatment to cause fusion between single fibers, fusion can be effectively caused by adding water. Therefore, it is possible to save thermal energy by lowering the heat treatment temperature, or to reduce costs by increasing the processing speed. (2) Since water can be used as a fusion promoter without using an organic solvent, it is extremely safe and economical, and can be easily adopted industrially as there is no concern about environmental pollution. The present invention will be specifically illustrated by examples below. In addition, the moisture content in Examples was measured by the following method. The water-applying device 3 is operated and the water-applied yarn is sampled between the water-applying device 3 and the false-twisting hot plate 4;
Measure the weight W ₁ . Then, the weight W ₂ after vacuum drying at 80° C. for 24 hours is measured, and the moisture content is calculated by equation (1) using the treatment agent adhesion amount p (%) determined by a conventional method. Example 1 Polyethylene terephthalate with an intrinsic viscosity of 0.63
The yarn was spun at 3200 m/min to obtain an undrawn yarn with 245 denier 48 filaments and a treatment agent coating amount of 0.6%. The obtained undrawn yarn was heated at a false-twisting hot plate temperature of 230°C and at a false-twisting speed using the drawing false-twisting apparatus shown in Fig. 1.
It was stretched and false-twisted at 230 m/min, a stretching ratio of 1.39 times, and a twist number of 2350 t/m. As the water application device 3, a metering extrusion device was connected to a ceramic guide having the shape shown in FIG. 2, and various moisture contents were obtained. The false twisting hot plate 4 had a length of 1.5 m, and the false twisting device 5 was a triaxial external friction false twisting device in which a rubber disk was inserted. The results are shown in Table 1, Experiment Nos. 1 to 3. For comparison, the same undrawn yarn was drawn and false-twisted under the same conditions without operating the water application device, and the results are shown in Experiment No. 4.

[Table] Note) ◎ Very well fused
○ Well fused × Not fused Example 2 The same undrawn yarn as in Example 1 was stretched 1.3 times with a draw-twisting machine to obtain a 160 denier thick yarn with a U% of 11%. Ta. The obtained thick and thin yarn was drawn and false-twisted using the apparatus shown in FIG. 1 at a drawing ratio of 1.1 times. False twist hot plate
It was 1.1 m long and used at 225°C. The number of twists is
The processing speed was 2000t/m and the preheating speed was 150m/min. A pin twist type was used as the false twisting device, and the same water application device as in Example 1 was used to give a 4.5%
The moisture content was set to . The results are shown in Table 2, Experiment No. 5. In addition, No. 6 shows the result of processing under the same conditions as No. 5 without applying water for comparison.

[Table] Note) ◎ Very well fused × Not fused As in Example 1, it is clear that fusion is promoted by adding water.

[Brief explanation of the drawing]

FIG. 1 is a front view of a stretch false twisting device showing an embodiment of the present invention. FIG. 2 is a plan view of an embodiment of the water application device. 1: Undrawn yarn, 2: Supply roller, 3: Water application device, 4: False twisting hot plate, 5: False twisting device, 6: Stretching roller, 7: Second hot plate, 8: Yarn feed roller, 9: Winding machine.

Claims (1)

[Claims] 1. In a device equipped with a supply roller, a heating means, a false twisting means, and a drawing roller in this order, the polyester undrawn yarn or partially drawn yarn is sent in the direction of the heating means by the supply roller, and as it is stretched, it fuses between the single fibers. A method for producing a fused false-twisted yarn, which comprises adding water to the undrawn yarn or partially drawn yarn after passing through a supply roller and before entering a heating means when false-twisting is performed while causing the above.