JPS60134012A - Spinneret for spinning acetate fiber having y-shaped cross-section - Google Patents

Abstract

PURPOSE:To spin a high-quality acetate fiber having Y-shaped cross-section and high resistance to aging, stably, by using a spinneret having plural nozzles having a specific cross-section and separated from each other by a specific distance. CONSTITUTION:The cross-section of the nozzle is defined by three straight lines (b) of the sides of a triangle 1 included in the circle 2 having its center at the center of gravity of the triangle and three arcs (a) of the circle 2 included in the triangle 1. A plurality of nozzles are bored with distances of >=2.5mm. between the centers. The length (l) of the arc (a) and the ratio of the arc length (l) to the length (L) of the straight line (b) are set preferably to >=0.006mm. and <=0.30 (preferably 0.23-0.30), respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The invention relates to an improvement in a spinneret for producing diacetate or triacetate fibers having a Y-shaped cross section suitable as filaments for clothing, staples and tow for cigarette filters. be.

[Prior art]

Conventionally, acetate fibers having a Y-shaped cross section have been produced using a spinneret having a spinning hole with an equilateral triangular cross-sectional shape as shown in Fig. Since the fibers are easily clogged, the spinning stability is poor, and furthermore, the cross-sectional shape of the spun fibers changes greatly over time, resulting in unstable quality.

The non-applicant has first proposed a spinneret that can solve the above problem.
A spinning hole with a cross-sectional shape drawn by a triangle and a circle that intersects each side of the triangle with the center of gravity of the triangle as the center, three arcuate parts inside the triangle and five straight parts inside the circle. A spinneret having the above structure was proposed in Japanese Utility Model Application Publication No. 58-176968, but in order to put it into practical use, it was necessary to study the details of the spinneret in detail.

[Purpose of the invention]

The uninvention is a Y-shaped cross-sectional setite with a pebble crystal quality that changes over time.
[Structure of the Invention] The gist of the invention is to provide a spinneret that can spin fibers in an extremely stable manner. Among these, in a spinneret in which a plurality of spinning holes are formed, each having a cross-sectional shape drawn by five circular arc parts inside a triangle and three straight parts inside a circle, the length t of the circular arc part is 00.
06 or more, the ratio t/L of the t and the length L of the straight section is Q
, 30 or less (preferably 0.23 to α50), and the center-to-center distance between adjacent spinning holes is 2.5111+11 or more.

The present invention will be explained in more detail below with reference to the drawings.
The figure is a sectional view showing an example of a spinning hole in a nozzle according to the invention, and in the figure, the part indicated by a solid line is a spinning hole,
The spinning hole is located between an equilateral triangle (1) and a circle (2) that intersects with each side of the equilateral triangle (1) centered on the center of gravity (0)' of the equilateral triangle (1). It has a shape drawn by three circular arc parts (a) and six surface line parts (tl) inside.

In the non-invention, the length t of the circular arc portion (a) is 0.00
6- or more, and the ratio t/L of the l to the length L of the straight portion (b) is 0.30 or less, preferably 0.23 to 0.50.
It must be in the range of , and if t is 0.006, then
As the spinning stability decreases, the cross-sectional shape of the spun fibers changes over time, and when t/L exceeds 0.50,
It becomes difficult to maintain a Y-shaped cross section, and the bulkiness, which is a feature of Y-shaped cross-sectional fibers, decreases. In addition, the distance between the centers of adjacent spinning holes must be 2.5 degrees or more; if it is less than 2.5 degrees, the cross-sectional shape of the spun fibers will change significantly over time.

In Fig. 2, the triangle (1) is made into an equilateral triangle in order to increase the processing precision of the spinning hole and reduce the variation in fineness and physical properties among the spun fibers, but in the present invention, the triangle (1) is not necessarily an equilateral triangle. There is no need for it, and other triangles may be used as long as there is no problem in terms of processing accuracy.

In addition, in order to form a yarn containing a mixture of fibers with different cross-sectional shapes, the spindle of the present invention has a spinning hole for spinning Y-shaped cross-section fibers as described above.
It is not a problem even if spinning holes for spinning fibers with other cross-sections, such as round cross-sections, are mixed, but in this case as well, the distance between the centers of adjacent spinning holes must be 2.5 Wm or more.

Hereinafter, the invention will be explained in more detail with reference to Examples.

[Example 1] When diacetate fibers were dry-spun using a conventional method, a spinneret having spinning holes shaped as shown in FIGS. With various changes as shown in the table 7
A setate filament yarn with a Y-shaped cross section of 5 (1/15) was spun.The results are shown in the same table.

311II+.

Table 1 "1- [Kari-'1- ゛"1] Shi- Twill Toughness- Hokuseifu- Suwo Note 1) The change over time of the fiber cross section is the most extensive in Table 1. The spinning surface f of experiment A5, which had a bad result, was evaluated as a degree of deformation of 1, and after 9 days of experiment 1, which showed the greatest change over time, tl - degree of deformation was determined on a 5-level scale of 5. Same note below. 2] The thread cutting frequency was expressed as the number of thread cuttings per 100 threads per day (the same applies below).

Note 3) Bulk height measurement method Using the device shown in Figure 7 using the bulk height measurement roll shown in Figure 6, the sample yarn (5) whose bulk height is to be measured is passed through the bulk height measurement roll (3) [constant]. Kit of sample thread that is wound under tension:
W i is measured, and the bulk height is calculated using the formula D = 7 a 54/W, and rounded to the second decimal place.

The bulk height shown in Tables 1 and 2 is the value measured for the sample immediately after spinning.

[Example 2] When dry spinning diacetate fibers using a conventional method, the first
Using a spinneret with a spinning hole shaped as shown in Figures and Figure 2,
In addition, acetate filament yarns with a YW cross section of 75 d/15 f were spun with various changes in the center-to-center distance of the spinning holes shown in FIG. 2, as shown in Table 2, and the results are shown in the same table. Furthermore, LFiQ of the spinning hole in Fig. 1 is 060 mmVc, and cvt of the spinning hole in Fig. 2 is [1010+Ba,, Lijo,
043m+n (therefore, t/L was set to [L23).

Table 2 Figure 4 (A
), (B), and the spinning ia of the fiber obtained in Experiment 4.
Figure 5 (A) shows the cross-sectional shape after 9 days.
Each is shown in (B).

[Example 3] When dry spinning triacetate UR fibers in a normal manner,
The spinning hole has the shape shown in FIG. 2 [t=α old 0 order, L=0.
040 questions, t/L=0.25] Arrange 9 spinning holes and 18 circular spinning holes in the order of diameter 0030 as shown in Figure 5, so that the distance between the centers of each spinning hole is 3.0 cylinders. When the fibers were spun using a spinneret drilled in a hole, good results similar to those in Experiment A4 of Example 2 were obtained in terms of thread cutting frequency and changes in Y-shaped cross-section fibers over time.

〔Effect of the invention〕

According to the invention configured as described above, a special effect is achieved in that high quality Y-shaped cross-section acetate fibers with little change over time can be spun extremely stably.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a spinning hole of a conventional Y-shaped cross-section acetate fiber spinning nozzle, FIG. 2 is a cross-sectional view showing an example of a spinning hole of a Y-shaped cross-section acetate fiber spinning nozzle according to the invention, and FIG. is a plan view of the spinneret used in Example 3, FIG. 4(A),
CB) is a cross-sectional view of the fiber obtained in Experiment A1 of Example 2 immediately after spinning and after 9 days, and FIG.
(B) Cross-sectional view of the fiber obtained in Experiment A4 of Example 2, immediately after spinning and after 9 days, Figure 6 is a front view of the roll for bulk height measurement, and Figure 7 is a view of the bulk height measuring device. In side views, in FIGS. 2 and 7, (1) is an equilateral triangle, (2) is a circle centered on the center of gravity (0) of the equilateral triangle (1), (3) is a roll for bulk height measurement, (4) is tension measurement quality, (5) is Sunfool yarn, (a) it arc part, (b
l is a straight line portion.

Claims (3)

[Claims] (1) A cross-sectional shape drawn by three arc parts inside the triangle and three m-line parts inside the circle, among a triangle and a circle that intersects each side of the triangle with the center of gravity of the triangle as its center. In a spinneret with a plurality of spinning holes having 1. A spinneret for spinning acetate fiber in Y-shaped cross section, characterized in that the center-to-center distance between holes is 2.5 W or more. (2) The Y-shaped cross-section acetate fiber spinning die according to claim 1, wherein t/L is 0.23 to 1L30. (3) The Y-shaped cross-section acetate fiber spinning nozzle according to claim 1 or 2, wherein the triangle is an equilateral triangle.