JPS6352128B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for inexpensively producing mixed denier yarn with good texture. It has been known for a long time to produce woven and knitted fabrics with excellent surface touch and firmness by using a blended yarn with a large single-filament denier yarn in the core and a small single-filament denier yarn in the surface layer. ing. Such woven and knitted fabrics usually have a shrinkage rate of yarn with a large single denier,
It is obtained by weaving, weaving, and shrinking mixed yarns with a shrinkage rate higher than that of single yarns with a small denier. This method requires separate production of yarns with different single yarn deniers, resulting in lower productivity and higher costs. Moreover, it is difficult to uniformly mix separately spun or drawn yarns during processing, and for this reason, the texture has not yet been fully satisfied. On the other hand, in order to eliminate this drawback, in the polyester spinning process, the yarn is melted and discharged from two or more groups of spinning holes with different diameters, and each yarn group is combined and wound. Public bulletin) has been proposed. According to this method, it is possible to produce a blended yarn in which two or more types of undrawn yarns with different single filament deniers and degrees of orientation are sufficiently mixed only in the spinning process, which increases productivity and is advantageous in terms of cost. In addition, the mixed fiber state is also made uniform. However, when this mixed fiber yarn is made into a woven or knitted fabric, there is a drawback that the surface touch is poor and the texture is dull. That is, in the mixed fiber yarn produced by the above-mentioned simultaneous spinning, as is clear from Example 1 of the above-mentioned Japanese Patent Application Laid-Open No. 10-120001, yarns with a large single filament denier have a low orientation.
Since the yarns with a small single filament denier are highly oriented, when weaving and knitting, the yarns with a small single filament denier are present in the core, and the yarns with a large single filament denier are located in the surface layer and touch the surface. You can only get a bad texture. As a result of repeated research in order to eliminate the drawbacks of such conventional methods, the present inventors have found that even when simultaneous spinning is adopted, the discharge amount per spinning hole is made different for each spinning hole group, and each spinning hole group The present invention was achieved based on the discovery that the molecular orientation (expressed by birefringence) can be adjusted by applying a tension difference to the yarns discharged from the yarn. That is, the present invention involves melt-spinning a thermoplastic synthetic resin through two types of spinning hole groups to form two types of yarns with different single filament deniers, and then combining the yarns to produce a mixed denier yarn. The discharge amount per spinning hole of each spinning hole group is made different, and the birefringence of the yarn with a large single filament denier is 1.3 times or more that of the birefringence of the yarn with a small single filament denier. This is a method for producing a mixed denier yarn, characterized in that the bundle length of yarns with a large single filament denier is made longer than the bundle length of yarns with a small single filament denier. The focusing length in the present invention is the distance from the discharge surface of the spinneret to the focusing guide. In addition, the thermoplastic resin to which the present invention is applied has a yarn tension during melt spinning that is
Any material may be used as long as it can be changed by changing the focusing length, and polyester, nylon, etc. are particularly suitable. According to the present invention, such a melt-spun synthetic resin is melt-discharged from a plurality of spinning hole groups by varying the discharge amount per spinning hole for each spinning hole group. The plurality of spinning hole groups mentioned here may be provided in separate spinnerets. It is sufficient that each spinning hole group is configured so that the discharge amount per spinning hole is different from each other, and even if the hole diameter or the number of holes is different, the discharge amount per hole can be different. However, in the case of industrial implementation, it is particularly suitable to use a plurality of spinnerets having the same spinning hole diameter but different numbers of spinning holes. Even if the difference in the discharge amount per hole in each spinning hole group is small, a certain texture can be obtained, but when there are two spinning hole groups as in the present invention, yarns with a large single denier It is preferable that the single yarn denier is 1.2 times or more the single yarn denier of the yarn with a small single yarn denier. In the present invention, as described above, a plurality of yarns are melted and discharged from a plurality of spinning hole groups, and the bundled length of the yarns with a large single filament denier is made longer than the bundled length of the yarns with a small single filament denier. By doing this, yarns with a large single filament denier experience more air resistance and yarn tension, compared to yarns with a small single filament denier, and as a result, the molecular orientation of the yarn increases. That is, the birefringence becomes large. The degree to which the focusing length is increased is such that the birefringence of the yarn with a large single filament denier is larger than that of the yarn with a small single filament denier, and preferably the birefringence of the yarn with a large single filament denier is If the refractive index is △n ₁ and the birefringence of a yarn with a small denier is △n ₂ , it is preferable that △n ₁ /△n ₂ ≧1.3. When △n ₁ ≦△n ₂ , the yarn with a large single filament denier will not be placed in the core and the yarn with a small single filament denier will not be placed in the surface layer, resulting in poor surface touch. Also, when 1 < △n ₁ / △n ₂ < 1.3, the yarn with a larger single yarn denier is placed in the core and the yarn with a smaller single yarn denier is placed in the surface layer, but this cannot be said to be sufficient. . Moreover, there is little sense of volume. In the present invention, groups of yarns with different single filament deniers are bundled separately and then oiled and combined, or the yarns are bundled and combined first and then oiled near the bundled part. It is more preferable to use an interlace nozzle to mix and entangle the yarns, since the fibers are mixed uniformly and loops and yarn breakage are prevented in the steps after spinning. The spinning speed is preferably in the range of 2000 to 5500 m/min. When the spinning take-off speed is less than 2000 m/min, the change in yarn tension due to the convergence length becomes small, so the suitable range becomes narrow. Next, it will be explained using drawings. The drawing is a schematic side view of a spinning device showing a preferred embodiment of the present invention, in which 1 and 1' are spinnerets, 2 is a cooling air blowing part,
3 and 4 are focusing guides, 5 is an oiling roller,
6 and 7 are godet rollers, 8 is an interlace nozzle, 9 is a winder, 10 is a bobbin,
Y and Y' represent a yarn with a large single denier and a yarn with a small single denier, respectively. In the figure, the yarn Y with a large single denier discharged from the spinneret 1 and the yarn Y' with a small single denier discharged from the spinneret 1' are directed from the cooling air blowing part 2 in a direction perpendicular to the yarns. It is cooled by the cooling air blown out. Both of the cooled yarns Y and Y' are focused by focusing guides 3 and 4, respectively. The distances from the mouthpiece surface to the focusing guides 3 and 4, that is, the focusing lengths L and L', satisfy L>L'. In general, it is better to shorten the bundle length L' of yarns with a small single filament denier as long as it does not adversely affect the yarn quality, and to make the bundle length L of yarns with a large single filament denier as large as possible based on the spinning equipment, to create a sense of volume. A woven or knitted fabric with a good surface texture can be obtained. In our experiments, it was preferable to set L≧3m and 0.2m≦L′<2m. If L′ is too short, there is a problem that uneven fineness and adhesion will occur. Yarn Y and
Y' is oiled by an oiling roller 5 and then taken up by a godet roller 6. The yarns Y and Y' taken off by the godet roller 6 are mixed and entangled in an interlace nozzle 8 provided between the godet roller 7 and the godet roller 7. The interlace nozzle 8 is a known nozzle described in Japanese Patent Publication No. 36-12230, and the degree of interlace is usually 30 to 80.
It is adjusted to a range of 6/m. The interlace nozzle may be located between the godet rollers 6 and 7 or between the godet roller 7 and the winder 9 . The interlaced mixed fiber yarn is Godet Roller 7.
After that, it is wound onto a bobbin 10 by a winder 9 . After winding, it is stretched as necessary. The mixed fiber yarn obtained by the above method is extremely economical because it can be produced in one step by spinning and spinning, and the yarn with a small single filament denier has low orientation and low shrinkage, so it can be woven easily. When made into a knitted fabric, it is located in the surface layer, and the yarn with a large single yarn denier is highly oriented and has high shrinkage, so it is located in the core of the woven or knitted fabric, giving it a firm waist and good surface touch, as well as a voluminous feel. It has the advantage of providing a certain excellent texture. Example Dry chips of polyethylene terephthalate (containing 0.3% by weight of titanium oxide) with an intrinsic viscosity [η] of 0.64 measured in an orthochlorophenol solution at 35°C were used in the spinning apparatus shown in the drawing, and a spindle of 0.15φmm for fine single yarn was used. ×72H and 0.15φmm×36H for thick single yarns were melted and discharged at a melting temperature of 298°C and a discharge amount under the conditions shown in the table below. The two groups of yarns that were discharged were cooled in the usual way with cooling air at 25°C, then the convergence length was changed as shown in the table below, and the yarns were oiled in the usual way, and taken up at the spinning take-off speed shown in the table below. It was rolled up and used as a package. At this time, the fibers were mixed at an air pressure of 4.5 Kg/cm ² G using an interlacing nozzle having a thread passage hole of 2.0 φ mm and a pressure hole of 0.8 φ mm at the position shown in the drawing. Next, the obtained mixed fiber yarn is stockinette knitted at 100℃.
It was subjected to a moist heat treatment for 20 minutes and its texture was examined. The results are shown in the table below.

【table】

【table】 [Brief explanation of drawings]

The drawing shows a schematic front view of a spinning device illustrating an embodiment of the present invention. 1 and 1' are spinnerets, 3 and 4 are focusing guides,
6 and 7 are godet rollers, 8 is an interlace nozzle, 9 is a winder, and Y and Y' are a yarn with a large single yarn denier and a yarn with a small single yarn denier, respectively.

Claims (1)

[Claims] 1. A thermoplastic synthetic resin is melt-spun through two types of spinning holes to form two types of yarns with different single filament deniers, and then the yarns are combined to produce a mixed denier yarn. In this process, the discharge amount per spinning hole of each spinning hole group is made different, and the birefringence of the yarn with a large single filament denier is 1.3 times or more that of the yarn with a small single filament denier. A method for producing a mixed denier yarn, characterized in that the bundle length of yarns with a large single yarn denier is made longer than the bundle length of yarns with a small single yarn denier. 2 The single yarn denier of the yarn with a large single yarn denier is the same as that of the yarn with a small single yarn denier.
A method for producing a mixed denier yarn according to claim 1, which is 1.2 times or more. 3. The method for producing a mixed denier yarn according to any one of claims 1 to 2, wherein the take-up speed of melt spinning is 2000 m/min or more.