JPH0217656B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a spun yarn-like processed polyester yarn that can give the appearance and feel of a woven or knitted yarn. Conventionally, in order to impart a spun yarn-like appearance and texture to polyester yarn, there have been methods in which crimped yarn is treated with fluid agitation to give it bulk and fluff, or crimped yarn is rubbed. Various processing methods have been proposed, including a method of generating fluff by adding bulkiness and fluff. However, all of these processing methods require multiple steps such as crimping and fluffing, which not only increases the processing cost, but also increases the processing cost by using fluid agitation treatment to add fluff to the resulting processed yarn. Because it has teardrop-like coarse loop fuzz, when made into cloth, it has the disadvantage of inducing the so-called fastener phenomenon in which the cloths get caught on each other.
In addition, the method of imparting fuzz by rubbing has the disadvantage that the processed yarn has cut fuzz, resulting in poor pilling performance. The present inventors have proposed a method for producing a spun yarn-like polyester false twisted yarn that does not have such drawbacks and can impart an appearance and texture similar to that of a woven or knitted yarn. After that, we have already applied for a method of heat-stretching and false-twisting.
It was proposed in No. 56-199169. The yarn obtained by the above invention has a spun yarn-like appearance, with the outer layer having crimped crimp and arch-shaped loop fuzz, and the inner layer having a core made of fused filament. It has the advantage of giving firmness, waist, etc. However, because excessive loops are mixed in the arch-shaped loop fluff in the outer layer, the loop fluff gets entangled with each other on the winding material such as cheese, reducing the unwinding property during weaving and the opening property during weaving. There was a disadvantage that the strength was low and that fuzzing was likely to occur. The inventors of the present invention have conducted intensive studies in view of the above points, and have found that the relaxation heat treatment temperature is lower than that of the above invention, the draw ratio during false twisting is increased, and the yarn after the relaxation heat treatment is subjected to room temperature tension treatment. According to
The present invention was developed based on the knowledge that it is possible to make the arch-shaped loop fuzz in the outer layer finer and also to make the yarn uniform and bundled.The purpose of this invention is to create a crimp crimp with a fine and uniform outer layer. The inner layer has a filament core made of fused and bonded arch-shaped loop fluff, and it not only has a spun yarn-like appearance and texture, but also has excellent unwinding properties, opening properties, and strength during knitting and weaving. An object of the present invention is to provide a method for producing a spun yarn-like polyester processed yarn with improved properties. That is, in the present invention, highly oriented polyester undrawn yarn with a birefringence △n of 15 to 80 × 10 ^-3 and a crystallinity of 20% or less obtained by high-speed spinning is subjected to a heating device in a relaxed state of 30% or more. The yarn is heat-treated at a temperature of 180°C or lower without contact, and after passing through a relaxation heat treatment zone, is subjected to a tension treatment at room temperature while reaching a stretching false-twisting heater, and the yarn is stretched to satisfy the following formula (1). This is a method for producing a spun yarn-like polyester processed yarn, which is characterized by drawing and false twisting at a magnification of A. A>1.1 (1+a/100) (1) where a: relaxation rate (%) The present invention will be described in detail below. The supplied yarn used in the method of the present invention is an undrawn polyester yarn having a birefringence Δn of 15 to 80×10 ⁻³ and a crystallinity of 20% or less. In the present invention, as described later, the above-mentioned yarn is first subjected to relaxation heat treatment to sufficiently shrink the yarn, and then crystallization is promoted without significantly changing the degree of orientation in the fiber axis direction, thereby reducing the residual elongation. increase.
Furthermore, since it can be sufficiently shrunk by relaxing heat treatment, it is not a drawn yarn but an undrawn yarn, and there is less problem of thermal embrittlement in heat treatment processing including drawn false twisting, so high speed spinning (e.g. spinning speed) is possible. 2500〜
5500m/min) and the birefringence △n obtained is 15~
It is necessary to use a highly oriented undrawn polyester yarn having a yarn quality characteristic value of 80×10 ^-3 and crystallinity of 20% or less. Here, if the birefringence △n of this highly oriented polyester undrawn yarn is less than 15 × 10 ^-3 , yarn breakage will occur frequently due to embrittlement of the yarn during the drawing false twisting process that follows the relaxation heat treatment, and the drawing false twisting will occur. Processing becomes difficult. Moreover, if it exceeds 80×10 ⁻³ , it is not preferable because it becomes difficult to run the yarn while sufficiently contracting it in a relaxed state. In addition, the degree of crystallinity must be 20% or less; if it exceeds 20%, the improvement in the degree of orientation during stretching and false twisting will be small, and if anything, the disorder of orientation due to heat shrinkage will cause fiber embrittlement. This is not desirable because it becomes Next, the present invention provides the highly oriented polyester undrawn yarn with a relaxation rate of 30% or more in a relaxation heat treatment zone, and a relaxation rate of 180% or more.
Heat treatment is performed at a temperature below ℃ without contact with a heating device, and the single filaments that make up the yarn are randomly shrunk in the longitudinal direction, so that some of the single filaments in the cross section of the yarn have a large fineness and a single filament. A yarn with a difference in length between filaments is formed. Here, the relaxation rate refers to the ratio of the difference between the supply speed and the take-up speed to the take-up speed, expressed as a percentage. The relaxation rate during the above-mentioned relaxation heat treatment must be 30% or more, preferably 50% or more, and the relaxation rate must be such that sufficient shrinkage can be achieved. If the relaxation rate is less than 30%, it is not preferable because it becomes difficult to provide the yarn with a two-layer structure consisting of a crimped crimp and a core portion fused together with arched loop fluff by the draw false twisting process described later. Further, the relaxation heat treatment must be carried out without bringing the yarn into contact with a heating device so that the single filaments constituting the yarn can be sufficiently shrunk at any position. If the above-mentioned treatment is performed by bringing the yarn into contact with a heating device, tension is applied due to the contact resistance of the yarn, which inhibits contraction at a free position, which is not preferable. The temperature during relaxation heat treatment is 180℃ or less.
Within the temperature range that allows shrinkage of 30% or more, preferably 160
Need to be ~140℃. By heat-treating at 180℃ or below, the crimped crimp and arched fuzz that make up the outer layer of the processed yarn obtained by the room-temperature tension treatment and stretch false-twisting process described later become finer, and the yarn becomes even. The strength improves as it becomes more concentrated and focused. If the temperature during the above-mentioned relaxation heat treatment exceeds 180°C, the two-layer structure of the resulting processed yarn becomes clear, but the unwinding property deteriorates due to the presence of excessive arch-like fluff, and further heat embrittlement occurs. This is not preferable because the strength also decreases. In the present invention, the yarn obtained by the above-mentioned relaxation heat treatment is subjected to simultaneous stretching and false-twisting by being subjected to room-temperature tensioning treatment between the time it leaves the relaxation heat treatment zone and the stretch and false-twisting heater. To obtain a spun yarn-like polyester yarn having a two-layer structure in which a core part is formed of a filament with an inner layer part fused and bonded, and the core part is covered with fine and uniform crimp crimp and arch-shaped loop fuzz. In this case, the above-mentioned room temperature tensioning treatment may be performed by gripping the yarn leaving the relaxation heat treatment zone with a roller or the like, or by retroactively applying the tension during stretching and false twisting without gripping the yarn. The latter is preferable in order to make the crimp fluff that forms the outer layer of the processed yarn fine and uniform. Also,
If the yarn tension at room temperature is too high, cut fuzz will occur and the workability will be reduced, while if it is too low, the arch-like loop fuzz that occurs in processed yarn will not be evenly balanced, and large loop fuzz will be mixed. I'll come. Therefore,
The yarn tension should be in the range of 0.05 to 0.20 g/d.Furthermore, the longer the tension time at room temperature, the more effective it is in equalizing the arched loop fuzz, so it depends on the yarn speed and fineness, but it can be as long as 1 second. It is preferable to maintain the above. In addition, the stretching ratio A during simultaneous stretching and false twisting is selected as a ratio that satisfies A>1.1 (1+a/100) and does not cause cut fuzz, assuming that the relaxation ratio during relaxation heat treatment is a%. There is a need. When the stretching ratio satisfies the above conditions, a difference in the amount of torsional deformation occurs between the inner and outer layers of the yarn during drawing and false twisting, forming a core in which the inner layer is fused and bonded, and the outer layer is crimped finely and uniformly. It is possible to have a two-layer structure with crimps and arched loops, and the strength of the yarn is also improved. on the other hand,
If the stretching ratio is smaller than the above, although the film has a two-layer structure, the uniformity of the arched loop fluff will be insufficient and the strength will also be low, which is not preferable. In addition, the temperature during the above-mentioned stretch false-twisting is not particularly limited, and processing can be performed at a normal false-twisting temperature, but if the false-twisting temperature is too high, the proportion of the inner layer that is fused and bonded increases, resulting in two layers. Textile-like appearance due to structure,
The texture decreases, while if the false twisting temperature is too low, the degree of convergence of the yarn decreases. Therefore, the crimped crimp and arched loop fluff forming the outer layer of the processed yarn and the fused portion of the filament forming the inner layer are appropriately bundled, improving unwinding properties, opening properties, etc. during weaving and weaving. In order to achieve this, the false twisting temperature is preferably 210 to 230°C. Furthermore, the number of false twists during drawing and false twisting is determined by setting the yarn fineness after drawing to D (denier) and the appropriate number of false twists to T ( times/m), then T=
It is preferable to set the number of false twists to 18,000/√ to 28,000/√, which is slightly lower than the usual false twist number, from the viewpoint of clarifying the two-layer structure of the processed yarn and improving the unwinding property. FIG. 1 is a schematic process diagram showing an example of the manufacturing process of the method of the present invention. The highly oriented undrawn yarn F obtained by high-speed spinning is pulled out from the spool 1, passes through the tensor 2, passes through the feed roller 3, and is 30%
The material is supplied in the above-mentioned relaxed state, and is taken up by the first delivery roller 5 while being contracted in a non-contact state within the relaxation heater 4 whose temperature is 180° C. or less. The yarn is subsequently fed into the drawing/false twisting zone, where it is drawn at a predetermined stretching ratio between the first delivery roller 5 and the second delivery roller 8 and at the same time is false twisted by the false twisting spindle 7 . At this time, the yarn sent out from the first delivery roller 5 is first maintained in a room temperature atmosphere under tension, and then reaches the drawing false twist heater 6 without being gripped by rollers or the like, where it receives heat. As the effect is applied and the material is further stretched, it is simultaneously false-twisted using a false-twisting spindle 7 and heat-set using a stretching false-twisting heater 6. The yarn thus processed is wound into a package 10 by a winding roller 9 into a spun yarn-like bulky processed yarn. In addition, as shown in FIG. 2, a reheat treatment heater 1 is installed between the second delivery roller 8 and the take-up roller 9.
1 is provided, and the yarn exiting the second delivery roller 8 is heat-treated in a relaxed or tensioned state to change the bulkiness, reduce torque, and thermal stability, and then is passed through the third delivery roller 12 and wound. The package may be rolled up into a package 10 by a pick-up roller 9. The processed yarn obtained by the method of the present invention has a two-layer structure, as shown in Fig. 3, in which the outer layer has fine, evenly distributed crimp and arch-like loop fuzz, and the inner layer has a core made of fused filament. It has a spun yarn-like appearance, and the firmness and stiffness provided by the fused core gives it a texture similar to wool spun yarn, making it a spun yarn that closely resembles spun yarn in both appearance and texture. Thread-like threads are obtained. In addition, in the yarn obtained by the present invention, the crimped crimp and arched loop fuzz forming the outer layer are finely and evenly distributed.
In addition, the core of the filament bonded to the outer layer is moderately bundled, improving the unwinding property during weaving and the opening property during weaving, and further improving the strength. It is possible to prevent the occurrence of fuzz on the fabric. Note that the polyester in the present invention is a general term for polyesters containing ester bonds in the molecular chain, typified by polyethylene terephthalate, and also includes modified polyesters containing a third component such as isophthalic acid and paraoxyethoxybenzoic acid. Hereinafter, the method of the present invention will be specifically explained using Examples. Example: Highly oriented undrawn polyester yarn obtained by high-speed spinning (birefringence △n 55×10 ^-3 , crystallinity 9.7%)
Using the apparatus shown in FIG. 1 with 230d/48f as the raw yarn supplied, drawing and false twisting was performed under each condition shown in Table 1 to produce a spun yarn-like processed yarn. In addition, the supply yarn speed during each trial production condition was 100 m/min,
The number of false twists was 1700 times/m. Further, the stretching ratio of the formula (1) was 1.76 at a relaxation rate of 60%, which is the processing condition shown in Table 1. Table 1 shows the results of evaluating the uniformity, degree of convergence, yarn form, and strength of the processed yarns obtained under each condition. As is clear from Table 1, the processed yarn obtained in Example 1 of the present invention has good uniformity, convergence, and strength, and the outer layer has a uniform fine crimp and arched loop shape. The yarn had fluff, the inner layer had a core formed of fused filaments, and had a two-layer structure with a spun yarn-like appearance. When this processed yarn was used for the warp and weft and weaved at a warp density of 52/inch and a weft density of 88/inch, the openness during weaving was good, and the finished fabric could be finished with normal dyeing. As a result, a fabric was obtained which had fine loops without unevenness on the surface of the fabric, had no cut hairs, and had a spun yarn-like appearance and feel. On the other hand, yarns with a higher relaxation heat treatment temperature than the present invention (Comparative Example 1) and yarns with a low draw ratio and extremely low tension at room temperature (Comparative Examples 2 and 3) The shape was not satisfied at the same time, and the strength was also lower than that of Example 1.

[Table] However, the degree of uniformity is determined by observing the yarn with a loupe under a load of 0.02g/d, and taking the average thickness of the yarn as B.
The number of loops per meter of loops with a thickness of 2B or more was determined as follows. ◎…10 or less, 〇…11-20, △…21-30, ×…31
that's all. In addition, the degree of convergence is set at a yarn speed of 150 m/min and the unwinding tension of the yarn during tube knitting using a Visigraph manufactured by Sanei Sokki Co., Ltd., so that the average tension is 1 g, and a chart as shown in Figure 4 is drawn. The following procedure was performed depending on the number of pieces with an unwinding tension of 5 g or more per 1000 m. 〇...5 or less, △...6-15, ×...16 or more. Furthermore, the yarn morphology was evaluated based on the appearance of the yarn from the clarity of the two-layer structure as follows. 〇...Good, △...Normal, ×...Bad.

[Brief explanation of drawings]

FIG. 1 is a schematic process diagram showing an embodiment of the present invention;
FIG. 2 is a partial process diagram showing another example of the above, FIG. 3 is a schematic side view of an example of spun yarn-like polyester processed yarn obtained by the present invention, and FIG. 4 is a yarn yarn obtained by the present invention. It is a graph showing the unwinding tension of. In the figure, 3 is a feed roller, 4 is a relaxing heater, 5 is a first delivery roller, 6 is a stretched false-twisting heater, 7 is a false-twisting spindle, 8 is a second delivery roller, and 9 is a take-up roller. .

Claims (1)

[Claims] 1. Birefringence △n obtained by high-speed spinning is 15 to 80
×10 ^-3 , a highly oriented polyester undrawn yarn with a crystallinity of 20% or less is heat-treated at a temperature of 180°C or less in a relaxed state of 30% or more without contacting with a heating device,
The yarn that has passed through the relaxation heat treatment zone is subjected to a tension treatment at room temperature while reaching a stretch/false twist heater, and the yarn is subjected to a stretch/false twist process at a stretching ratio A that satisfies the following formula (1). A method for producing spun yarn-like polyester processed yarn. A>1.1 (1+a/100) …(1) where a: relaxation rate (%)