JPH0241174Y2 - - Google Patents

Description

[Detailed explanation of the idea]

<Industrial Application Field> The present invention relates to a spinneret used for dry spinning, and particularly to a spinneret for spinning Y-shaped cross-section yarns applied to tobacco filters and the like. <Prior Art> Generally, acetate fiber bundles are aligned and used as fibers for tobacco filters. Since the efficiency of removing harmful components from tobacco smoke differs depending on the cross-sectional shape of the fibers, fibers with various cross-sectional shapes have been developed for this cigarette filter. Among these, fibers with a Y-shaped cross section are particularly effective;
An equilateral triangular nozzle has been developed as a nozzle for spinning yarn into a letter-shaped cross section (US Pat. No. 2,829,027). However, when spinning with an equilateral triangular nozzle, the spinnability is lower than that of regular-shaped fibers spun with a circular nozzle, resulting in more yarn breakage during spinning, resulting in poor yields and fluffing of the fibers. Many flies (floating threads) are falling off during the winding process. These flies will become defective if they get mixed into the tobacco filter. In order to solve this problem, a polygonal base in which the apex of an equilateral triangular base is cut out by a straight line or a circular arc has been developed (Japanese Patent Publication No. 10611/1983).
However, when the vertex of an equilateral triangle is cut off with a straight line, a new vertex is created by the sides of the equilateral triangle and the cut line. Since the angle of this vertex is wider than that of an equilateral triangle, the amount of foreign matter deposited at the vertex is reduced, which improves spinnability, but flies still occur frequently. On the other hand, when partially cutting along an arcuate line, positioning of the device is troublesome, processing is difficult, and the shape of each single yarn is difficult to be the same. The present invention was made in consideration of the above circumstances, and provides a spinneret that has high spinnability and is easy to process. <Means for Solving the Problems> The present invention is basically a polygonal base with the apex cut off from an equilateral triangular base, but it is molded into a nonagonal shape. In other words, in the cap according to the present invention, three circular arcs drawn with a radius smaller than L and larger than 0.88L centering on each vertex of an equilateral triangle with a side length L are connected to each side and median line of the equilateral triangle. It is characterized by being formed into a nonagonal shape formed by connecting the intersecting points with straight lines in order. <Operation> A nonagon formed by connecting arcs drawn from each vertex of an equilateral triangle to the intersections of each side and median of the equilateral triangle basically approximates the shape of an equilateral triangle, but the vertices of the equilateral triangle The three new vertices corresponding to the sections have wide angles, contributing to improved spinnability. Moreover, the six vertices formed on the sides of the equilateral triangle have a wider angle and are substantially the same as a straight line, which suppresses fluffing and contributes to reducing flies. <Examples> Examples illustrating the present invention will be specifically described below. FIG. 1 is a front view of an embodiment of the cap according to the present invention. This cap 1 is formed into a nonagonal HNPJQSKTM shape in which an equilateral triangle ABC is cut out by a straight line. In such forming, a circle with a radius R of 0.88L≦R<L is drawn centering on each vertex A, B, and C for the length L of one side of an equilateral triangle ABC, and each arc is drawn on each side of the equilateral triangle. , , the point that intersects M.
NPQST and median of equilateral triangle,,
This is done by sequentially connecting the points H, J, and K that intersect with with straight lines. If the radius R is larger than L, the arc will not intersect the equilateral triangle and a nonagon will not be formed. On the other hand, if the radius R is smaller than 0.88L, the overall size becomes small and the shape is far from that of an equilateral triangle, making it impossible to improve the spinnability of an equilateral triangle. The cap 1 formed in this way has a long side such as PN of 0.05 to 0.06 mm, and a length of L.
and R are selected to have such dimensions. Also, each side of the equilateral triangle is each vertex HNPJQSK
Since it is cut by a straight line connecting T and M, processing is easy. Here, the vertices H,
J and K are formed at the narrowest angle, but the vertices H, J and K may be flat as shown in Figure 2a, or arcuate as shown in Figure 2b. There is no problem with spinning. This is because, as mentioned above, the cap itself is extremely small and the angles of the vertices H, J, and K are narrow, so that the shape shown in the second figure is obtained by processing. Example 1 Acetate flakes with an acetylation degree of 54.3% were dissolved in acetone, and 3-denier Y-shaped cross-section yarns were spun using the spindle of the present invention and an equilateral triangular spindle as a comparative example. The base of this invention has a L of 0.063mm and an R of 0.063mm.
It is molded with a length of 0.058 mm (equivalent to 0.92 L), and the cap of the comparative example is molded with a length of 0.06 mm. The results are shown in Table 1. In Table 1, the maximum draft refers to the highest draft rate within a range in which yarn breakage does not occur, and the draft rate is calculated from the spinning winding speed/the raw solution discharge linear speed. According to the spinneret of the present invention, the maximum draft rate for yarn spinning is high and productivity is improved.

[Table] Example 2 Using the same die and acetate flakes as in Example 1, a 36,000 denier/12,000 filament tow was spun at 60°C. Also, this tow was used to wind up a cigarette filter plug at a speed of 400 m/min. Table 2 shows the number of yarn breaks during spinning and the amount of fly during winding. In addition, the rod properties (weight hardness, ventilation resistance) of the filter plug obtained in this way
There was almost no difference between the present invention and the comparative example.

[Table] <Effects of the invention> As described above, the invention is based on an equilateral triangle and has a nonagonal shape with the vertices of the equilateral triangle cut out by straight lines, which makes processing easier and improves spinnability. It has the effect of improving the amount of fried food and reducing the amount of fried food. Further, according to the present invention, since the spindle can always have a constant shape due to the ease of processing described above, the cross-sectional shape of the single yarn to be spun is also approximately constant, and quality can be maintained.

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of the present invention, and FIGS. 2a and 2b are enlarged front views of main parts. 1...Cap.

Claims (1)

[Scope of utility model registration request] Three circular arcs drawn with a radius smaller than L and larger than 0.88L centered on each vertex of an equilateral triangle with side length L connect the points where three arcs, each drawn with a radius smaller than L and larger than 0.88L, intersect with each side and median line of the equilateral triangle in order with a straight line. A spinneret for Y-section fibers, characterized in that it is formed into a nonagonal shape.