JPH0231126B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for inexpensively producing a mixed fiber yarn of different fineness and cross section with good texture. It has been known to produce knitted fabrics with excellent surface touch and stiffness by using a mixed yarn in which yarns with a large single filament fineness are intertwined in the core and yarns with a small single filament fineness in the surface layer. That's about it. Such knitted fabrics are usually obtained by weaving and shrinking mixed yarns in which the shrinkage rate of yarns with a large single filament fineness is higher than that of yarns with a small single filament fineness. However, with this method, it is necessary to separately manufacture yarns with different single filament finenesses, resulting in low productivity and high costs, and it is difficult to uniformly mix yarns spun or drawn separately during processing. I have not reached the point where I am completely satisfied with the texture. In addition, in the polyester spinning process, a method has been proposed in which the yarn is melted and discharged from two or more groups of spinning holes with different diameters or numbers of spinning holes, and the yarns are combined and wound. According to the method, it is possible to produce a mixed yarn of different fineness, in which yarns having different single yarn finenesses and different orientations are uniformly mixed, just by the spinning process, which increases productivity and is advantageous in terms of cost. However, in this method, yarns with a large single filament fineness become poorly oriented, and yarns with a small single filament fineness become highly oriented. Since the large yarns are located in the surface layer, a good texture cannot be obtained. As a result of repeated research in order to solve the problems of the conventional method, the present invention has been developed to differentiate the fineness of single yarns formed in each spinning hole group even when simultaneous spinning is employed, and to If the yarn formed from the spinning hole group has an irregular cross-section and the elongation difference is given to the yarn discharged from each spinning hole group, it is possible to use a yarn with a large single filament fineness in the core and a single yarn in the surface layer. The present invention was achieved by discovering that it is possible to position yarns with small yarn fineness. In other words, the gist of the present invention is that when two types of yarns with different single yarn finenesses are simultaneously melt-spun to form a mixed yarn with different finenesses, a thick single yarn is used as a yarn with an irregular cross section; By spinning the yarn so that the single yarn fineness of the yarn is 1.1 to 5.0 times that of the fine single yarn, the residual elongation of the thick single yarn is equal to the residual elongation of the fine single yarn. A method for producing a mixed fiber yarn of different fineness and different cross section, which is characterized by arranging a thick single fineness yarn in the core part and a fine single fineness yarn in the surface layer part. The yarn in the present invention includes polyester,
Threads such as polyamide and polypropylene may be mentioned, but polyester thread is most preferably used. In addition, the simultaneous spinning method in the present invention may be either a method of simultaneously spinning from separate spinnerets or a method of simultaneously spinning from different spinning holes of the same spinneret; Any known method may be used, such as a method of varying the discharge amount per spinning hole, a method of varying the number of spinning holes, and a method of varying the diameter of the spinning holes. Furthermore, the irregular cross section in the present invention may be either flat or polygonal, but it has a larger quenching effect during cooling than the spun yarn from the other spinning hole group, and the hole area per spinning hole is larger. Certain cross-sections are preferred, and best results are obtained especially when using flat cross-sections. When providing a difference in the discharge amount per hole between spinning hole groups, a certain effect can be obtained even if the difference is small. In addition, as for the difference in the single yarn fineness of the yarns from each spinning hole group, the single yarn fineness of the yarn with a large single yarn fineness is 1.1 to 5 times that of the yarn with a small single yarn fineness. Preferably, if it is less than 1.1 times, the effect of different fineness cannot be obtained, and conversely, if it exceeds 5.0 times, the fineness of the thick single yarn fineness yarn will become too large, and the quenching effect during cooling will be insufficient, and the fineness of the thick single yarn fineness yarn will be insufficient. It is difficult to make the residual elongation smaller than the residual elongation of fine single-filament yarn. The present invention will be explained in detail below with reference to the drawings. FIG. 1 is a front view of a spinning apparatus used in carrying out the present invention, in which 1 and 1' are spinnerets, 2 is a cooling air blowing part, and 3 and 3' are yarns with large single filament fineness (unusual shape). 4 is an oiling roller, 5 and 7 are godet rollers, 6 is an interlace nozzle, 8 is a traverse guide, 9 is a winder, and 10 is a bobbin. In the same figure, a yarn 3 with a irregular cross section with a large single filament fineness discharged from the spinneret 1 and a yarn 3' with a small single filament fineness discharged from the spinneret 1' are connected to the yarn from the cooling air blowing part 2. Cooling is achieved by cooling air blown in orthogonal directions. After the cooled yarns 3 and 3' are oiled by an oiling roller 4, they are oiled by a godet roller 5.
It will be picked up at The yarns 3 and 3' taken off by the godet roller 5 are mixed and entangled in an interlace nozzle 6 provided between the godet roller 7, and then wound onto a bobbin 10 by a winder 9 via the godet roller 7. The mixed fiber yarn obtained by the above method can be manufactured all at once in the spinning process, which increases productivity, and yarns with a small single filament fineness have a higher residual elongation than yarns with a large single filament fineness. When knitted fabrics are made, yarns with a large single filament fineness, i.e. irregular cross-section yarns, are located in the surface layer and have a small residual elongation, so they are placed in the core, giving them a good texture, firmness, and volume. Excellent knitted fabrics can be obtained. Figure 2 shows yarn B with a large single yarn fineness according to the present invention.
are the stress and elongation curves of each yarn when A is a flat cross section and yarn A with a small single yarn fineness is a round cross section,
It can be seen that the residual elongation of the yarn B, which has a large single filament fineness, that is, the yarn with a knitted flat cross section, is smaller than the residual elongation of the yarn A, which has a small single filament fineness, that is, the round cross section yarn. Next, the present invention will be explained in more detail with reference to Examples. Example After melting polyethylene terephthalate with a relative viscosity of 1.625 at 290°C, the spinning device shown in Fig. 1 was used, and the spinneret was 0.25〓× for fine single-filament yarn.
48 ^H , thick single yarn fineness yarn (0.1 mm x 2.0 mm) x 10 ^H was melted and discharged at a discharge rate of 29.0 g/min. The two discharged yarns were cooled and solidified in air at 25° C., and after oiling, they were wound at a spinning speed of 2000 m/min to obtain a mixed fiber undrawn yarn of 261 denier and 58 filaments. As shown in Figure 2, the stress and elongation curves of each single component of the obtained yarn are as follows: Results were obtained that were smaller than the average. In other words, by making a yarn with a large single filament fineness an irregular cross section, the residual elongation differs due to draft differences, discharge behavior differences, and cooling behavior differences (the residual elongation on the thick single yarn side, that is, on the irregular cross section yarn side is small). A mixed fiber yarn with different fineness and different cross-sections (with a large residual elongation on the fine single yarn side) was obtained. The results of various studies are shown in the table below.

[Table] (Note) No. 4 is a comparative example

[Brief explanation of drawings]

FIG. 1 is a front view showing an example of an apparatus used in carrying out the present invention, and FIG. 2 is a stress-induced stress between thick single-filament fineness yarn B and fine single-filament fineness yarn A of the mixed yarn obtained by the present invention. In the elongation curve shown in Figure 1, 1 and 1' are spinnerets, 2
3 is a thick single yarn, 3' is a fine single yarn, 4 is an oiling roller, 5 and 7 are godet rollers, 6 is an interlace nozzle, 8 is a traverse guide, 9 is a winder, and 10 is a cooling air blowing part. It's a bobbin.

Claims (1)

[Claims] 1 When two types of yarns with different single yarn finenesses are simultaneously melt-spun to form a mixed yarn with different finenesses, the thick single yarn fineness yarn is used as the irregular cross-section yarn, and the single yarn fineness of the thick single yarn fineness is fine. By spinning the yarn so that the fineness of the single yarn is 1.1 to 5.0 times that of the single yarn, the residual elongation of the thick single yarn is made smaller than that of the fine single yarn, and the yarn is made with a thick single yarn. A method for producing a mixed fiber yarn of different fineness and different cross section in the core part, which is characterized by arranging fine single yarn fineness yarn in the surface layer part.