JPS5938330B2 - Manufacturing method of split-fiber processed yarn - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing ultrafine yarn by peeling and splitting composite fibers made of at least two types of incompatible polymers.

Various such methods have been proposed.

When undrawn composite fiber yarns made of at least two types of incompatible polymers having complex cross sections are simply stretched, peeling is insufficient and ultrafine yarns are not substantially obtained.

Therefore, a method has been proposed for producing ultrafine threads by further adding certain means.

For example, Japanese Patent Publication No. 39-29636 discloses a method for producing a fine-grained yarn with sharp corners by dissolving or chemically decomposing and removing one of the polymer components of a composite yarn with a complicated cross-sectional structure.

Furthermore, Japanese Patent Publication No. 48-28002 discloses a method for partially exfoliating the two components by false twisting a drawn yarn of a multilayer mixed fiber with a complex cross section consisting of two types of incompatible polymers. ing.

JP-A No. 51-67436 discloses a method of drawing and false twisting an undrawn composite fiber yarn with a complicated cross-sectional structure, partially exfoliating both components, and cutting one component to make it fluffy. It is shown.

However, if dissolution treatment or chemical decomposition is performed, not only will waste liquid treatment be expensive, but one of the components will be discarded, and the resulting fibers will inevitably be expensive.

In addition, with the conventional method of peeling and using both components, it is difficult to cause complete peeling, and there is a drawback that ultra-fine threads appear in some parts, but remain thick in other parts without being peeled off. Ta.

This drawback becomes more difficult as the target fiber thickness becomes smaller and the cross-sectional structure becomes finer.

The present invention was achieved by intensively searching for a method to improve these drawbacks and obtain a split-woven yarn with a good degree of release.

That is, the gist of the present invention is as follows.

Consisting of at least two types of thermoplastic polymers that are not compatible, one polymer component occupies one continuous region within the cross section of the fiber, and the other polymer component is divided into a plurality of small regions, and When simultaneously drawing and false-twisting an undrawn yarn of a composite fiber having a cross-sectional structure in which at least two of the small regions are exposed on the surface of the fiber and at least - polymer components are continuous in the longitudinal direction of the fiber, a feed roller is used. A patent characterized in that a cold drawing pin maintained at a temperature below the softening point of the polymer constituting the undrawn yarn of the composite fiber is provided between the first heater and the undrawn yarn of the composite fiber, and the yarn is brought into contact with the drawing pin. A method for producing ultra-fine processed yarn with good splitting properties.

A feature of the present invention is that it can effectively peel off composite fibers in which the boundaries between composite components intertwine and form long, complex curves, which was previously considered to be extremely difficult to peel. One feature is that the thus obtained fibers having deep valleys or fin-like protrusions on the surface, especially fibers with a complex surface morphology of 1 denier or less, can be easily produced.

The cross-sectional shapes of fibers that can be effectively exfoliated in the present invention include cases where the boundaries of the composite components are smooth curves with a large radius of curvature as shown in Figure 1, as well as those shown in Figures 2 to 6. Examples include fibers with a cross-sectional structure in which the boundary lines are long and intricately curved.

Furthermore, combinations of polymers that can be used in the present invention are particularly effective combinations with low compatibility, such as nylon 6 and polyethylene terephthalate, nylon 6 and polyethylene or polypropylene, and polyethylene terephthalate and polyethylene or polypropylene. A highly elastic and adhesive polymer copolymerized with polyethylene glycol is made of a relatively compatible polymer, such as nylon 6 or polypropylene, which is a combination that is more difficult to peel off, as well as a combination of nylon 6 and polyethylene. 50Vo1% nylon 6 in terephthalate or polypropylene
It is also effective for composite fibers with complex cross-sectional structures, such as combinations of tri-blended mixtures.

In the present invention, undrawn yarn refers to fibers with a residual elongation of 60% or more.

FIGS. 7 and 8 show how the stretching pin of the present invention is used.

In the figure, 1 is a package of undrawn yarn in the composite edge area, 2 is a feed roller, 3 is a cold drawing pin, 4 is a fiber bundle guide, 5
is a first heater, 6 is a spindle, and 7 is a draw roller.

The cold drawing pin 3 is made of metal or ceramics with a hard chrome plated surface and has a diameter of 10 mWφ~1.
It is a rod-shaped body of 001nrILφ.

The guide is made of almost the same material as the cold drawing pin and is shown in Figures 7 and 8.
Any suitable shape as shown in the figure can be used.

In short, it is sufficient as long as the fiber bundle is restrained and brought into stable contact with the cold drawing pins.

The speed ratio (hereinafter referred to as DR) between the feed roller 2 and the draw roller 7 is appropriately changed depending on the physical properties of the undrawn yarn.

The main part of the present invention is the cold drawing pin, and the method of bringing the fiber bundle into contact with the cold drawing pin is to temporarily separate the fiber bundle from the cold drawing pin using a guide as shown in FIG. 7 and bring it into contact again, or as shown in FIG. It is possible to continuously contact the fiber bundle with the cold drawing pin, and it is desirable that the fiber bundle goes around the cold drawing pin at least once.

When undrawn composite fiber yarn is drawn and false-twisted at the same time in this way, the threads are rubbed by the drawing pins, the drawing action in the fiber axis direction, and the shearing action caused by the false twisting are combined to intensively impart to the threads. This makes it possible to split even composite fibers with complex cross-sectional structures.

The temperature of the drawing pin needs to be below the softening point of the polymer constituting the undrawn yarn of the composite fiber.

If the temperature exceeds the softening point, the split fibers will fuse together again, making it impossible to obtain ultrafine yarn.

FIG. 9 schematically shows a split composite yarn obtained by the present invention.

10 and 11 schematically show split weaving yarns made by a method other than the present invention for comparison.
The figure shows the case where cold drawing pins are used for stretching and false twisting.
FIG. 11 shows the case of simply stretching.

The effects of the present invention are clear from these figures.

The present invention is particularly effective when the processing speed is high.

In the conventional draw false twisting method (without cold drawing pins), when the speed is increased, the fiber splitting becomes poor, and when the speed is about 150 m/min, the fiber shape obtained is intermediate between those in Figures 10 and 11. However, when the method of the present invention is followed at the same processing speed, a splitting state approximately the same as that shown in FIG. 9 can be obtained.

When the fibers shown in Figure 9 and the fibers shown in Figure 11 are made into a knitted fabric, the texture is different, and no matter how much bending treatment is applied to the knitted fabric in the subsequent process, the texture shown in Figure 9 will be different. It is not possible to obtain a soft-touch texture like that of knitted fabrics made from fibers with a good splitting degree.

Example 1 Relative viscosity 1.380 (concentration 0.5.
Polyethylene terephthalate with a relative viscosity of 2.62 (value measured at 25°C using 96% concentrated sulfuric acid at a concentration of 1, !i'/100·ml). Using a special composite spinneret, nylon 6 was produced with a cross-sectional structure as shown in Figure 2, with the continuous phase being nylon 6 and the six divided small regions being polyethylene terephthalate.

120 so that the single yarn fineness of the undrawn yarn is 15 denier.
An undrawn yarn of 16 filaments spun at a speed of 0 m/min was processed as shown in FIG. 7 under the following conditions.

False twisting drawing machine; FK-5C8 (Bermarg cold drawing pin temperature; room temperature drawing pin diameter; 40mvtφ 1st heater temperature; 180°C Spindle rotation speed; 550,00 Or, p, m number of false twists; 2750T/M DR: 3.5 Processing speed: 200 m/min The yarn obtained was a mixed fiber yarn in an almost completely split state as shown in FIG.

A closer look shows that there is a 04 denier polyethylene terephthalate filament with a cross-sectional shape that resembles the shape of the moon around the 10th or 20th day of the moon, and a 1.67 denier polyethylene terephthalate filament with a star-shaped cross-sectional shape.
It is a 70 denier crimped yarn made of Neal's nylon 6 filaments.

When this yarn was wefted and plain woven with 70D/24f nylon 6 yarns as warp yarns, a silk-like fabric with slight crimps appearing on the surface and no slimy feel was obtained.

When this fabric was dyed with acid dye, it was dyed in a uniform light color and no heathering appeared.

Furthermore, when the fibers obtained in this example were circularly knitted, they had a very flexible and light structure.

Example 2 Using the same nylon 6 and polyethylene terephthalate as in Example 1, the cap device was changed to have a cross-sectional structure as shown in Figure 3, the continuous phase was polyethylene terephthalate, and the speed was 2000 m/min. obtained by spinning with
An undrawn yarn of 180 denier 16 filaments was drawn and false twisted under the following conditions using cold drawing pins (diameter 40 mm) at room temperature as shown in FIG.

False twist drawing machine; FK-5C8 (Bermarg Co., Ltd.) No. 1
Heater temperature: 180°C Spindle rotation speed: 540,00 Or, p, m False twist number: 2700T/M DR: 1.8 Processing speed: 200 m7 The obtained processed yarn was almost completely split. It was a bulky crimped yarn in a good mixed fiber state, consisting of polyethylene terephthalate filaments with a water wheel-like cross section with a single yarn fineness of 4 denier and nylon 6 filaments with a single yarn fineness of 0.3 denier and a crescent-shaped cross section.

When this fiber was knitted into a circular knitted structure, it had firmness, good recovery, no wrinkles, and a very soft texture.

Example 3 Using the same nylon 6 and polyethylene terephthalate as the polymers used in Example 1, and using the same die device as used in Example 1, the continuous phase polymers were nylon 6 at 60 Vo 1% and polyethylene terephthalate at 40 Vo.
A blend polymer mixed to have a Vo of 1%,
Spinning was carried out under substantially the same conditions as in Example 1 so that the six divided small regions consisted only of polyethylene terephthalate, and the undrawn yarn was wound up.

The cross-sectional structure of this undrawn yarn was as shown in FIG.

This undrawn yarn was drawn and false twisted under substantially the same conditions as in Example 1.

The obtained fibers are also almost completely split, and include ultrafine polyethylene terephthalate yarns with various cross-sectional shapes, mixed fibers in which nylon 6 and polyethylene terephthalate are mixed in a single yarn, and bulky processed yarns. It became.

Comparative Example 1 A processed yarn was produced by removing the cold drawing pins and keeping the other conditions exactly the same as in Example 1. A crimped bulky yarn was obtained, but when the cross section was observed under a microscope, it was found that 10
The peeling state was about halfway between that shown in the figure.

This was circularly knitted, but compared to the knitted fabric obtained in Example 1, it was clearly inferior in flexibility, lightness, and feel.

When mechanical bending was applied to this knitted fabric, the texture improved somewhat, but the texture was inferior to that of the knitted fabric obtained in Example 1.

[Brief explanation of the drawing]

FIGS. 1 to 6 show cross-sectional views of composite fibers with complex cross-sectional shapes that can be used in the present invention. FIGS. 7 and 8 are schematic diagrams of a drawing/false-twisting apparatus used to carry out the present invention, and particularly show the cold drawing pins and the state in which yarn is applied thereto. FIG. 9 schematically shows the splitting state of the splitted processed yarn obtained by the present invention. FIG. 10 and FIG. 11 are schematic diagrams showing the split state of a multi-section composite yarn obtained by a method other than the present invention. 1: Package, 2: Feed roller, 3: Cold drawing pin, 5: First heater, 6: Spindle.

Claims (1)

[Claims] 1 Consisting of at least two types of thermoplastic polymers that are not compatible, one polymer component occupies one continuous region within the cross section of the fiber, and the other polymer component is divided into multiple small regions, and When simultaneously drawing and false twisting an undrawn yarn of a composite fiber having a cross-sectional structure in which at least two of the small regions are exposed on the surface of the fiber and at least one polymer component is continuous in the longitudinal direction of the fiber, A cold drawing pin maintained at a temperature below the softening point of the polymer constituting the undrawn yarn of the composite fiber is provided between the roller and the first heater, and the yarn is brought into contact with the drawing pin. A method for producing ultra-fine split yarn with a good splitting degree.