JPS60259623A - Production of polyester fiber for wadding - Google Patents

Abstract

PURPOSE:To produce the titled fiber having high toughness and resistance to getting limp, and having a cross-section characterized by a pair of hollow parts extending along the longitudinal direction of the fiber, by spinning two kinds of polyester polymers having different melt viscosity through a specific spinneret. CONSTITUTION:A polyester polymer 3 having low molt-viscosity and a polyester polymer 4 having high melt-viscosity are supplied side-by-side and extruded through a spinneret furnished with a nozzle having radially disposed three slits each having a circular hole at the end. The melt-viscosity difference between the polymer 3 and the polymer 4 is >=500 poise. A polyester fiber containing a pair of parallelly disposed hollow parts and having a dent and a protrusion at the outer circumference of the cross-section can be produced by this procedure.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a method for producing polyester fiber for stuffing that is strong and does not easily sag. [Background Art] Polyester fiber has excellent fiber performance. In recent years, there has been an increase in demand in the field of filling cotton for mattresses and comforters, but in mattresses and comforters, the cotton has a high bulkiness, especially when no load is applied, and a person sleeps on it. It is required that the bulkiness (referred to as "stiffness") under high loads and the decrease in bulkiness (referred to as "settling") after repeated use be small. Polyester fibers, which have a fiber cross-sectional shape in which two hollow parts are connected in the longitudinal direction of the fiber, are extremely suitable for this field of cotton filling applications, but it is still difficult to maintain such a stable fiber cross-sectional shape. It has not been adopted industrially because there is no method for forming it. In other words, the method usually adopted to improve the bulkiness of stuffed cotton is to make the cross-sectional shape of the fibers hollow as shown in Figure 2 to increase the stress against deformations such as bending and screwing. This is a method of imparting a latent crimpable three-dimensional spiral crimp by composite spinning, but the method of making the cross-sectional shape of the fiber hollow does not mean that the higher the hollowness ratio, the more the waist and sag will increase. However, as the hollowness ratio increases, the deformation of the hollow shape during the mechanical crimping process, especially the flattening, increases, so there is a limit to the improvement of waist and heel 90. When using the method of imparting a three-dimensional spiral crimp with latent crimp property, as shown in Figure 3, the hollow ratio is small as a result of the balance effect and surface tension effect of the molten polyester on the low melt viscosity side peculiar to composite spinning. As a result, the effect of improving lower back and fatigue is on the verge of being diminished. In addition, in the latent crimp three-dimensional spiral crimp, the entanglement between the fibers is thick and the load can be reduced to 1.
．． No, @ (7) Jr, 3,1□, it has a big□ texture.

Polyester fibers with an fC fiber cross-sectional shape in which two hollow portions are connected in the longitudinal direction of the fiber have a small hollowness per se, but are resistant to deformation of the cross-sectional shape, such as ridges, bends, twists, etc. It has mechanical properties of Excellent: 0.7, even though it shows high stress. As a method for forming such a fiber cross-sectional shape, a method has been proposed in which a thermoplastic polymer is melt-spun using a spinneret having spinning discharge holes as shown in Figure 4 (Tokyo Kagaku Dojinsha, Fiber Structure and Development). ), P26) However, the ratio of two hollow portions formed in the fiber cross section is low, and many fiber cross-sectional shapes as shown in FIG. 5 are mixed. In order to improve this drawback, when a spinneret having a spinning discharge hole with a narrow bridge portion shown in FIG. 6 is used, a new drawback arises in that the bridge portion is damaged by the discharge pressure of the molten polymer.

[Purpose of the invention]

The object of the present invention is to provide a method for stably producing bolyhete fiber for stuffing, which has a fiber cross-sectional shape in which two fibers are connected in the longitudinal direction of the fiber, and is strong and does not easily collapse into one piece. It is in.

[Structure of the invention]

In the present invention, two types of polyester polymers with different melt viscosities are arranged side-by-side and guided to a discharge hole. By melt-spinning two types of polyester polymers with melt viscosities different by at least 500 voids using a spinneret having a discharge hole with a cross-sectional shape of This is a method for producing polyester fiber for batting, which is characterized by forming a cross-sectional shape of the fiber.

The present invention will be described in detail below with reference to the drawings.

Specifically, as shown in FIG. 1, the cross-sectional shape of the fiber in which the two insides are continuous in the longitudinal direction of the fiber obtained by the present invention is a length in which two hollow portions of equal size are arranged in parallel. The cross-sectional shape of the fiber is circular, and the outer edge of the cross-section has one four part (the part indicated by 1 in Fig. 1) and one convex part (the part indicated by 2 in Fig. 1). .

FIG. 7 shows an example of an embodiment of the discharge hole used in the present invention, which has a cross-sectional shape in which three slits having a circular hole at the tip are arranged radially. In Figure 7, three surin'
Ll + L2 + "3 width ol.

ω2. ω3 (distance), diameter of the hole at the tip of each slit 'k dl, d2. as (mm), ol the center of the circular hole.

When 02 + 03, L2. Centered on the center point O where L3 connects, 0. ．． The radius of the arc connecting 02 and 03 is rftt@, Ll and L2. L2 and IJ311J3
The angle of each eaves sandwiched between LI and K is θILθ23.
When θ31 (degrees), r needs to be in the range of 0.5 to 1.0-5, preferably 0.6 to 0.8-. r
If it is less than 05-, the manufacturing precision of the discharge holes will be poor and the cross-sectional shape of each discharge hole will be non-uniform. Also, r is 1.0 (wII+
+) f exceeds, large kneading occurs when the molten polyester polymer is discharged from the discharge hole, and intermittent thick and thin bumps are formed in the longitudinal direction of the single fibers, which is not preferable.

(1) Ratio of I and r (al+/r)Id [11-0.
2 It is necessary that it is preferably in the range of 0.12 to 0.17; if it is less than 0.1, the spinning draft becomes excessive and yarn breakage becomes easy; if it exceeds 0.2, the hollowness ratio of the hollow part (
The area ratio of the hollow portion in the cross section of the fiber becomes small, which is not desirable. The ratio of ω1 and dl (ω+/(it), the ratio of ω? and d2 (ω2/d2), the ratio of ω3 and d3 (ω3/a*
') must be in the range of 03 to 0.9, preferably 04 to 08; if it is less than 03, the cross section of the fiber will be as shown in Figure 8, and a hollow part will not be formed. ,
Moreover, if it exceeds 0.9, the hollowness ratio of the hollow portion becomes small.

In the present invention, in order to make the hollow ratio of the two hollow parts as thick as possible and to make them equal, ω1=ω2−ω3, cl
, =d2=d, and θ12-023""OA+"
Most preferably, the temperature is 120 (degrees).Next, the molten fc two rods of polynisal polymer in the present invention are arranged side-by-side as shown in FIG. 9(a) and inserted into the discharge hole. Even with the same side-by-side type, if it is introduced into the discharge hole in the arrangement shown in Figure 9 (t+) and (C), the two hollow parts shown in Figure 9 (t+) and (C) will not be exposed. It is not possible to obtain a fiber cross-sectional shape that is continuous in the direction. The ratio of the two types of polyester polymers is preferably 40:60 to 60:40, preferably 50:50. In the present invention, the two types of polyester polymers having different melt viscosities may have different degrees of polymerization, for example. Polyester polymers obtained by copolymerizing a polyester polymer with other copolymer components, such as isophthalic acid, adipic acid, sodium isophthalate sulfonate, butanediol, etc. The same purpose can also be achieved by using The key is to use combinations that have different viscosities when melted, but in order to obtain the excellent fiber performance of polyester, it is preferable that at least 85 molt. or more of the constituent units consist of ethylene/terephthalate. .

The melt viscosity at the discharge hole during spinning of the two types of polyester polymers is at least 500 voids or more, preferably 80 voids.
It is necessary that the difference be 0 or more than 1'. 5
If it is less than 00 poise, the middle 9 part will not be formed. The reason for the formation of two hollow parts in the present invention is considered as follows. That is, when two types of polymers with different melt viscosities are disposed side-by-side and discharged, a kneeling phenomenon occurs in which the polymer with a lower melt viscosity presses and bends the polymer with a higher melt viscosity, as shown in Figure 10. , the degree of two-ring increases as the melt viscosity difference increases, as shown in Figure 11 (a
), '(b), <Q), a hollow portion is formed. (a) shows the case where there is no difference in melt viscosity, (b) shows the case where the melt viscosity difference is less than 500 voids, and (c) shows the case where the melt viscosity difference is 500 voids or more. In the present invention,
It is important which slit of the discharge hole with the cross-sectional shape shown in Figure 7 is discharged from which the polymer with low melt viscosity and the polymer with high melt viscosity are discharged. It is necessary to discharge the polymer in two slits and the high melt viscosity polymer in one slit in an equal arrangement. In the case of the arrangement shown in FIG. 12(b), no hollow portion is formed.

The bulkiness of the polyester fiber for stuffing obtained according to the present invention was measured as follows. After applying the sample to a card opening machine and making it into a sheet-like web, 15 Crn x 13 Cn
Cut out 1 rectangle and stack them so that the whole becomes 302.0.1? The height of the sample when a load of /cnP is applied is Ho (L:rn), 25? The height when a load of /crl is applied is Hl < tyn), and 259/crl
? The height of the sample after leaving it for 7 days with a load applied is I(2(α)), and the height of the sample measured after changing the load to 0.1 t/lyl is H3(crn, The bulkiness of the cotton stuffing when a person sleeps on it, i.e. the waist, is ul (cm)
corresponds to [7] The decrease in bulk after repeated use for a long time, ie +V, can be understood from a model using the following two equations.

2 -x 1o o (%) ---Lowering of bulk during use H
l 3 −X 100 (%) ---Recovery of bulk after use O [Examples] The present invention will be described below according to Examples.

Example relative viscosity (metacresol: 25°C) is 1.65 (!:
Two types of polyethylene terephthalate having a molecular weight of 1.55
2 Arranged in a double-side mold as shown in Figure 2 (a), guided to the discharge hole, and melt-spun at 290°C according to a conventional method.6
The undrawn polyester yarn of 4,800 denier and 200 filaments was obtained by winding the yarn in 1 minute. Polyethylene terephthalate with a relative viscosity of 1.65 and polyethylene terephthalate with a relative viscosity of 1.55 were weighed using a gear pump so that the ratio was 50:50. The r of the spinning discharge hole shown in Fig. 7 is 0.
．． 7 (pause), ωl, ω2. ω1 are all 0.1 (throat), dx, d+, dst″1. All are 0.2 (mm
).

θ12. θ23. θ31 was set to 120 (degrees) in both cases.

The cross section of the undrawn yarn thus obtained had the shape shown in FIG.

The above-mentioned undrawn yarn obtained in the present invention is bundled into a sliver, drawn at 60 m/min to 4.0 times, mechanically crimped, and then cut to form a sliver.
ThTh walla, 6 ar 2.6451. .

Polyester short fibers were obtained. The polyester short fibers were made into a web using a card opening machine, and the bulk was measured, which showed excellent f'L, elasticity, and fcv.

The results are shown in Table 1.

Comparative Example In the Example, two types of polyethylene phthalate having relative viscosities (metacresol: 25° C.) of 1.65 and 1.60 were combined, and the results are shown in Table 1 together with the Examples.

Table 1 [Effects of the Invention] According to the present invention constructed as described above, it is possible to obtain a polyester fiber for padding suitable for use in mattresses that has a strong elasticity and does not easily sag.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of an example of a hollow polyester fiber obtained by the present invention, Figure 2 is a cross-sectional view of a conventional hollow polyester fiber, and Figure 3 is a discharge hole of a spinneret for latent crimp hollow polyester fiber. The shape of the fiber and the arrangement of the two types of polyester polymers (a) and the fiber cross section obtained by this (b)
), Figure 4 is a diagram showing the shape of the discharge hole of the spinneret for obtaining the conventional two-way fiber cross-sectional shape in which the fibers are connected in the longitudinal direction, and Figure 5 is a diagram showing the shape of the discharge hole in Figure 4. Figure 6 is a fiber cross-sectional view of a large number of undesirable fibers mixed in the NYC fibers melt-spun from the discharge hole; FIG. 7 is an explanatory diagram of the shape of the discharge hole of the spinneret used in the present invention, and FIG. 8 is an explanatory diagram of the shape of the discharge hole of the spinneret used in the present invention. ω2 /(131ω3/
FIG. 9 is an explanatory diagram of the effect of the ratio of d3, and FIG. 10 is an explanatory diagram of the arrangement of two types of polyester polymers in the discharge hole introduction part and the positional relationship of the discharge holes in the present invention. FIG. 11 is an explanatory diagram of the principle of forming two middle 9 parts in the present invention, and FIG. 12 is a diagram illustrating the low melt viscosity polyester polymer 3 and the high melt viscosity polyester polymer 4 in the present invention.
An explanatory diagram ((a) is [##) according to the present invention] of the positional relationship between the (shaded area) and the slit from which the ejected liquid is ejected. 3... Polyester polymer on the low melt viscosity side 4... Polyester polymer on the high melt viscosity side "'"
-”+ 2 E3 Depression 3 Figure Sai 4 Figure + 5 Figure +67 Blue 8 Country + 9 Figure (()) (b) (C) +10 Separate +FF Eye Threat I2 Zo (0) (b)

Claims (1)

[Claims] 1. Two types of polyester polymers with melt viscosity are arranged side-by-side and guided to the discharge hole. By melt-spinning two types of polyester polymers that differ in melt viscosity by at least 500 voids using a spinneret with a cross-sectional discharge hole in which slits are arranged radially, two hollow parts are formed in the fiber length direction. A method for producing polyester fiber for filling, which is characterized by forming a continuous fiber cross-sectional shape. 2゜ Melt spinning is described in claim 1, in which two types of polyester polymers are introduced into a discharge hole in an arrangement in which a low melt viscosity polymer has two slits and a high melt viscosity polymer has one slit. the method of.