JPH10212624A - Splittable conjugated fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a splittable conjugated fiber capable of providing spun yarn for nonwoven fabrics and woven or knitted fabrics having good touch feeling and softness in good operability without causing sinking into a cylinder in carding process in producing nonwoven fabric. SOLUTION: In a splittable type conjugated fiber, composed of two kinds of fiber-forming polymer components A and B, in which the component A constituting a filament of a group having fine deniers and the component B constituting a filament of a group having coarse denier are separated into plural layers continuing in the longitudinal direction of fiber when split, single filament denier before splitting is 1.0-5.0 d and after splitting, average denier DMIN of single filament of a group having fine denier composed of the component A and average denier DMAX of single filament of a group having coarse denier group composed of the component B and average single filament denier DAVE of whole fiber satisfy the formula (DMAX-DMIN)/DAVH=0.1-1.5 (DAVE is denier before splitting/split number).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a splittable conjugate fiber comprising two types of fiber-forming polymer components which are incompatible with each other and divided into a plurality of single yarn groups in a post-processing step. More specifically, the present invention relates to a splittable conjugate fiber capable of obtaining a spun yarn for a nonwoven fabric or a woven or knitted fabric having excellent surface feel (feel) and flexibility with good workability.

[0002]

2. Description of the Related Art In recent years, nonwoven fabrics and woven or knitted fabrics having a good feel and excellent flexibility have been widely used for interlining, sanitary products, eyeglass wipes, and the like. Such non-woven fabric and woven / knitted fabric are
In order to provide good feeling and excellent flexibility, it is manufactured using ultrafine fibers having a small single-fiber fineness. Among them, splittable conjugate fibers composed of mutually incompatible fiber-forming polymer components are economically advantageous because they can be split into ultrafine fibers without using chemicals, and these are non-woven fabrics and woven and knitted fabrics. It is widely used in the production of spun yarn, and many proposals have been made.

For example, composite fibers composed of polyester / polyamide and polyester / polyolefin are used as mutually incompatible polymer components, and these composite fibers are divided in a post-processing step such as carding.
It becomes a very fine fiber. For this reason, when manufacturing nonwoven fabric,
Nep occurs in the carding process, or when the ultrafine fibers with a fineness of about 0.7 denier after splitting, fall down when drafting and winding with a card machine, sinking into the cylinder, etc. It has the disadvantage of causing operational problems.

[0004] Further, non-woven fabrics and woven or knitted fabrics made of ultrafine fibers have disadvantages in that they are inferior in bulkiness, and are liable to be set when worn for a long time, and lose heat retention and flexibility. As a method for solving this problem, Japanese Patent Publication No. 1-28141 proposes a heat insulating material for clothing using splittable conjugate fibers which are partially undivided. However, if undivided conjugate fibers or single yarns having a large fineness during the division are mixed, the resulting nonwoven fabric or woven or knitted fabric has a problem that the feeling and flexibility are greatly deteriorated.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and can be carried out with good operability without causing troubles in a carding step or the like when a conjugate fiber is divided into ultrafine fibers. An object of the present invention is to provide a splittable conjugate fiber from which a spun yarn for a nonwoven fabric or a woven or knitted fabric having good flexibility can be obtained.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention. That is, the present invention comprises two types of fiber-forming polymer components A and B which are incompatible with each other, and when divided, constitutes a yarn of the fine fineness group and a yarn of the large fineness group. In the splittable conjugate fiber in which the constituent B is separated into a plurality of layers continuous in the fiber longitudinal direction, the single-fiber fineness before splitting is 1.0 to 5.0 d, and the fineness of the component A after splitting is 1.0 to 5.0 d. division, characterized in that the average of the single yarn of a large fineness group consisting of average fineness D _MIN and component B of the single yarn of the group fineness D _MAX and the average of the total fiber fineness D _AVE satisfies the following formula (1) The present invention is based on a type composite fiber. (D _MAX −D _MIN ) / D _AVE = 0.1 to 1.5 (1) where D _AVE is the fineness before division / number of divisions.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to two types of fiber-forming polymer components A and B which are incompatible with each other. Component B constituting a group of yarns is a splittable conjugate fiber separated into a plurality of layers continuous in the fiber longitudinal direction, and the single yarn fineness before splitting is 1.0 to 5.0 d. 2 incompatible with each other
Examples of the kind of polymer combination (A / B) include polyester / polyamide and polyester / polyolefin. The splittable conjugate fiber of the present invention is easily split into ultrafine fibers in a post-processing step without using a chemical, and is particularly easily split in a carding step when forming a nonwoven fabric or a spun yarn. Is what you do.

The splittable conjugate fiber of the present invention needs to have a single yarn fineness before splitting of 1.0 to 5.0 d, more preferably 1.5 to 4.0 d. If the fineness before splitting is less than 1.0 d, the fineness of the single yarn after splitting becomes too small, so that sinking into the cylinder in the carding process becomes severe and the operability deteriorates. On the other hand, if the fineness before splitting exceeds 5.0 d, the spun yarn for a nonwoven fabric or woven or knitted fabric will have poor flexibility.

The splittable conjugate fiber of the present invention is obtained by dividing the average fineness D _MIN of the single yarn of the fine fineness group consisting of the component A, the average fineness D _MAX of the single yarn of the fine fineness group consisting of the component B, and the fiber. It is necessary that the entire average single fiber fineness D _AVE satisfies the above-mentioned expression (1).

[0010] That is, the average fineness D _MIN value obtained by dividing the difference between the average fineness D _MAX of single yarn with an average single fiber fineness D _AVE thick fineness groups single yarn fineness group after splitting is 0.1 to 1.5 If it is less than 0.1, the entanglement between the fibers is reduced, so that sinking into the cylinder during carding occurs, which is not preferable. In particular, this defect becomes more conspicuous as the average fineness after division is smaller. On the other hand, if it exceeds 1.5, there is no sinking into the cylinder, but the fibers are thick and the rigidity is high, so that the spun yarn for nonwoven fabric and woven / knitted fabric is inferior in flexibility.

The fineness before splitting is determined by measuring the fineness of the conjugate fiber according to JIS L1015 / 7.5.1A, and the fineness after splitting is finally obtained by using the splittable conjugate fiber. The fiber is taken out from the obtained nonwoven fabric, spun yarn, or the like, a cross section is photographed by an image processing machine, and the cross section is obtained.

Next, the shape of the splittable conjugate fiber of the present invention will be described with reference to the drawings. 1A to 1C are cross-sectional views showing an embodiment of the splittable conjugate fiber of the present invention.
(A) is a composite fiber having four convex portions, in which the convex portions are formed of component A and the central portion is formed of component B.
(C) is a composite fiber having three convex portions as in FIG. (B) is a hollow fiber, in which the outer peripheral portion other than the hollow portion is formed of components A and B. The number of divisions of each splittable conjugate fiber is (a) 5 and (b)
Is 16 and (c) is 4. The shape of the splittable conjugate fiber of the present invention is not limited to these, but if the number of divisions is too large, an undivided portion may occur, so that the number of divisions is about 3 to 20. Is preferred.

Next, the method for producing the splittable conjugate fiber of the present invention will be described. The splittable conjugate fiber of the present invention can be produced by a conventional method for producing a conjugate fiber. First, pellets of two incompatible polymers are dried under reduced pressure and melt-extruded by a composite spinning device. This is discharged from a composite spinneret, an oil agent is applied through a cooling hood, and wound up by a winder via a godet roller. Then, the yarn wound on the winder is bundled into a tow of about 100,000 denier,
The film is stretched at a predetermined stretching ratio with a heating roller, heat-treated using a heat drum or the like, and crimped using a press-type crimper or the like. Then, after the finishing oil is applied and dried, it is cut into a predetermined fiber length with a cutter to obtain a short fiber splittable conjugate fiber of the present invention.

[0014]

When the splittable conjugate fiber of the present invention is split in a post-processing step such as carding, the splittable conjugate fiber is made up of a component A constituting a fine fineness yarn and a component B constituting a large fineness yarn. Become
The average fineness D _MIN of the single yarns of the fine fineness group after division, the average fineness D _MAX of the single yarns of the large fineness group, and the average single fineness D of the whole fiber
_{Because AVE} is within the specified range, single yarns with high fineness after splitting prevent sinking into the cylinder during carding, and single yarns with low fineness can be obtained, such as spun yarn for nonwoven fabric or woven or knitted fabric. Can be improved and the flexibility can be improved.

[0015]

Next, the present invention will be described in detail with reference to examples. In addition, various evaluations, such as operability in an Example, were performed as follows. (1) Operability (Evaluation of sinking into cylinder during carding) In the carding process in the production of nonwoven fabric, the degree of sinking into the cylinder was visually evaluated in the following three stages. ：: No sinking Δ: Sinking was slightly observed ×: Sinking was severe (2) Bend-softness The non-woven fabric was evaluated for the bend-softness by the following three methods. (a) 45-degree cantilever method A 45-degree cantilever method was carried out in accordance with the method A of the rigidity test described in JIS L1096 / 6.19.1. Five pieces of 2 x 15 cm nonwoven fabric pieces were sampled to measure the length and width, and the softness indicating the softness was evaluated based on the length of the test piece, and each of the five sides was measured. And the average value for each of the vertical and horizontal directions. Height 80mm,
A width of 40 mm or less was regarded as a pass. (b) Total hand method The total hand method was carried out according to the rigidity test E method of JISL1096 / 6.19.5. Three pieces of nonwoven fabric of 10 × 10cm are collected and DAIE
A feeling meter (MODEL FM-2) manufactured by IKEKI was used. Put a piece of non-woven fabric on a slit with a width of 15 mm, and measure the maximum force required when the arm pushes the sample between the slits, at the front and back of the sample, in four directions in the vertical and horizontal directions. Find the total value. The average value of three nonwoven fabric pieces was determined, and a total value of less than 60 g was regarded as acceptable. (c) Tactile method A nonwoven piece of 20 × 20 cm was evaluated by a panelist according to the following five grades by tactile sensation. Evaluations 1 to 3 were considered acceptable. 1: Very flexible 2: Flexible 3: Normal 4: Stiff
5: Very hard (3) Fineness Measured by the method described above.

Example 1 A split-type composite fiber having a split number of 5 as shown in FIG. 1 was formed such that the component A was formed of polyester and the component B was formed of polyethylene. 280 ° C polyester and polyethylene polyethylene
It was melted at a temperature of 230 ° C and spun from a composite spinneret. The spun yarn was cooled through a cooling hood, applied with an oil agent, and wound up by a winder via a godet roller. This was bundled on a 100,000-denier tow, stretched using a heating roller at 70 ° C., heat-treated with a heat drum, and crimped with a push-in crimper. Thereafter, an oil agent was applied, dried, and then cut with a cutter to obtain a short fibrous splittable conjugate fiber (sufu) of the present invention. 65 g of this soup was put into a fiber opening machine (Yamato Kiko OP-200) to remove lump of cotton, sent to a hopper feeder with an air blowing fan, and then supplied to a card machine (Yamato Kiko SC-500). In this carding step, the splittable conjugate fiber was split. The nonwoven fabric web discharged from the card machine was needled with a needle room machine (Yamato Kiko, NL-500) having 192 punches / cm ² to prepare a needle punched nonwoven fabric. The obtained nonwoven fabric is heated to a temperature of 120.
And heat-treated for 1 minute with a continuous heat treatment machine (Tsujii Dyeing Machine Co., Ltd., NFD-500E). The target basis weight of the nonwoven fabric is 140 ± 5 g / m ² ,
The thickness was 1.40 ± 0.1 mm. Table 1 shows the results of the single fiber fineness before and after splitting the conjugate fiber, the evaluation of the operability in the carding process, and the evaluation of the stiffness and softness of the obtained nonwoven fabric.

Examples 2 to 6, Comparative Examples 1 to 5 Examples 2, 3, and 6 and Comparative Examples 1 to 4 were the same as those in Example 1 except that the fineness of the composite fiber before splitting was changed as shown in Table 1. The same was done. Examples 4 and 5 and Comparative Example 5 were carried out in the same manner as in Example 1 except that the B component was nylon 6, and the fineness of the composite fiber before splitting was changed as shown in Table 1. Table 1 shows the results of the single fiber fineness after division of the conjugate fiber, the evaluation of the operability in the carding process, and the evaluation of the rigidity and softness of the obtained nonwoven fabric.

[0018]

[Table 1]

As apparent from Table 1, the splittable conjugate fibers of Examples 1 to 6 had good operability in the carding process, and the obtained nonwoven fabric had sufficient flexibility. On the other hand, in the splittable conjugate fibers of Comparative Examples 1 and 5, the value of the expression (1) is 0.
Since it was less than 1, the splittable conjugate fiber of Comparative Example 3 had a single-fiber fineness of less than 1.0 d before splitting. Did not. Since the splittable conjugate fiber of Comparative Example 2 had a value of the formula (1) of more than 1.5, the splittable conjugate fiber of Comparative Example 4 had a single-fiber fineness before splitting of more than 5.0 d. Although the operability was good, the obtained nonwoven fabric was inferior in flexibility.

[0020]

Industrial Applicability The splittable conjugate fiber of the present invention can be carried out with good operability without causing sinking in a cylinder in a carding step in producing a nonwoven fabric, and a nonwoven fabric having excellent flexibility can be obtained. It becomes possible.

[Brief description of the drawings]

FIGS. 1A, 1B, and 1C are cross-sectional views showing an embodiment of a splittable conjugate fiber of the present invention.

Claims (1)

[Claims] 1. A fiber comprising two types of fiber-forming polymer components A and B which are incompatible with each other, and when divided, constitutes a yarn of a fineness group and a yarn of a fineness group. Component B
Is divided into a plurality of layers continuous in the fiber longitudinal direction, and the single-filament fineness before splitting is 1.0 to 5.
0 d, and after splitting, the average fineness D _MIN of the single yarn of the fine fineness group composed of the component A, the average fineness D _MAX of the single yarn of the large fineness group composed of the component B, and the average single fineness D _{AVE of the} whole fiber Satisfies the following formula (1): (D _MAX −D _MIN ) / D _AVE = 0.1 to 1.5 (1) where D _AVE is the fineness before division / number of divisions.