JPS5848668B2 - Tokushiyuhenshiyokubutsuno Seizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a novel knitted fabric having a special fluffy surface, and more specifically, the present invention relates to a method for producing a novel knitted fabric having a special fluffy surface, and more specifically, a fabric having a fluffy surface that is extremely fine and has different cross-sectional shapes and latitudes. The present invention relates to a method for manufacturing a knitted fabric that has a spun yarn-like appearance and feel that is resistant to pilling.

Conventionally, many methods have been proposed for fluffing continuous multifilaments to impart a spun yarn-like appearance and texture to knitted fabrics thereof.

Broadly speaking, these methods can be divided into (1) a method in which a file, knife, or equivalent object is brought into contact with a running continuous multifilament to cut the surface filament; and (2)
The method can be divided into methods in which fibers with different strengths or elongations are mixed and one of them is stretched, twisted, or blown with high-speed airflow under the conditions that one of the fibers is cut.

However, with these methods, it is difficult to control the uniform distribution and length of the fluff, and the fluff may fall off during the knitting process, or the fluff may easily move in the fiber length direction, resulting in a slub-nep look, resulting in yarn breakage, etc. Workability is markedly reduced, and when knitted fabrics are used, pilling tends to occur.Also, these knitted fabrics lack deep aesthetics and are monotonous because the cross-sectional shape and fineness of the fluff are almost uniform. Moreover, since the fluff is relatively thick, it has drawbacks such as a lack of warmth to the touch.

The present invention eliminates the drawbacks of such conventional methods, and produces knitted fabrics that have a special fluff on the surface that is extremely fine and has different cross-sectional shapes and finenesses, and that have a spun yarn-like appearance and texture that are difficult to pill. The purpose of the invention is to provide a method that can be manufactured with high productivity without causing the trouble of A composite undrawn yarn having 3 to 7 irregularities on the outer periphery of at least one of the core and sheath sections in the fiber cross section, and in which the core section occupies 20 to 70% of the fiber cross section is drawn. By twisting, the core part and sheath part are separated and the sheath part is divided into fine parts. Then, after knitting and weaving, the sheath part is treated with a chemical that dissolves or decomposes only the sheath part, and the sheath part is divided into five to five parts. A method for producing a special knitted fabric is characterized in that a large number of fluffs having different cross-sectional shapes and finenesses are developed on the surface of the knitted fabric by removing 50% by weight.

To explain the present invention in more detail, the combination of polymers used in the present invention is composed of fibers having different solubility or degradability with poor mutual affinity selected from the group of polyamides, polyesters, polyolefins, and polyvinyls. formative 2
It is limited to the range of polymer species that can be simultaneously spun from the same spinneret.

It is preferable that the two types of polymers have no mutual affinity at all, but it is sufficient that they can be easily peeled off by stretching, false twisting, or other physical methods.

Additives such as dyes, pigments, matting agents, antistatic agents, etc. can be added to each of the polymers, but in particular to the sheath polymer,
The present invention can be made more effective by adding additives that promote dissolution or decomposition of the sheath polymer, such as polyethylene glycols in polyethylene terephthalate.

When performing composite spinning of the above two types of polymers into a core-sheath type from the same spinneret, the cross-sectional shapes of the core and sheath portions in the filament cross section are extremely important, and the process stability during spinning and drawing, as well as the temporary It has a great influence on the performance of subdivision in twisting.

That is, at least one of the core or the sheath must have an unevenness on the outer periphery of its cross section, consisting of three to seven protrusions, as shown in FIG. 1, and the sheath must be constricted by the unevenness. If the number is less than 2, the fluff on the surface of the knitted fabric decreases, and the spun yarn-like appearance and texture that are the object of the present invention cannot be obtained.

In addition, if there are eight or more filaments, the cross section of the filaments approaches the usual concentric core-sheath type, making it difficult to subdivide the filaments by false twisting.

The shape of the unevenness is preferably a rotationally symmetrical shape in order to facilitate subdivision.

The ratio of the two types of polymers is preferably such that the core does not appear on the surface of the filament, and an appropriate area ratio of the core in the cross section of the filament is 20 to 70%.

If it is less than 20%, the core will be thickly covered with the sheath, making it difficult to separate and divide during false twisting, and if it exceeds 70%, the core will appear on the surface of the filament, causing division during spinning and drawing, which will cause problems in the process. Stability may be reduced.

There have been many proposals for core-sheath type composite spinnerets that provide such a cross-sectional shape, and any of these known ones can be used.

The undrawn yarn group obtained in this way is drawn and heat treated at a temperature suitable for the polymer with a higher glass transition temperature among the two types of polymers, and the two parts are peeled off and the sheath part is divided by false twisting. Ru.

In other words, the joint surface of the core-sheath part composed of two types of polymers with poor mutual affinity and the constricted part of the sheath part are separated by physical force such as twisting by a false-twisting spindle or friction with the false-twisting spindle. As a result, a group of crimped multifilaments is formed, which is composed of one thick fiber from the core and a plurality of thin fibers from the sheath.

The multiple fine fibers produced from the sheath have a complex cross section and different fineness as shown in Figure 2. False twisting is preferably carried out under conditions suitable for the sheath polymer, but peeling and splitting do not occur effectively. It's not just about tobacco.

The group of crimped maltefilaments is then knitted into a knitted fabric, and then treated with an agent that selectively dissolves or decomposes only the plurality of fine fiber polymers produced from the sheath.

Examples of such agents include formic acid or lime soda solutions in combination with nylon and polyethylene terephthalate.

Furthermore, for polyolefin polymers, tetralin,
For polyvinyl polymers such as xylene, tetrahydrofuran, dioxane, etc. can be used as good solubilizing agents.

As a result of the chemical treatment, a portion of the surface of the multiple fine fiber polymers produced from the sheath portion is eluted and removed, and as a result, these fine fibers are
Furthermore, the fibers become thinner and extremely fine, and some of them become fuzz because the thin parts of the thick and thin spots in the fiber length direction that occur during stretching and false twisting are cut off.

The fluff obtained in this way is extremely fine and has different cross-sectional shapes and finenesses, and the other end of the part protruding from the surface of the knitted fabric is held by the converging part of the group of crimped malte filaments, so it does not easily fall off. Protrudes uniformly on the surface of the knitted fabric.

The amount of elution of the sheath polymer by the drug depends on the stretching and false twisting conditions as well as the cross-sectional shape and fineness of the plurality of fine fibers generated from the sheath, but the majority of fluff will be in the range of 0.01 to 2 d. You just have to control it as you like, and the weight ratio is 5 to 5.
0% is appropriate.

If it is less than 50, the number of fuzz appearing on the surface of the knitted fabric is small and the spun yarn-like appearance and texture, which are the characteristics of the present invention, cannot be obtained;
If it exceeds %, the plurality of fine fibers generated from the sheath will be finely cut in the fiber length direction and easily fall off from the surface of the knitted fabric.

The appropriate fineness of the fluff is in the range of 0.01 to 2 d. If the majority of the fluff is 2 d or more, the knitted fabric will not have a warm feel, and if it is less than 0.01 d, the surface of the knitted fabric will have downy fuzz. The fibers grow densely, making it impossible to obtain a spun yarn-like appearance and texture.

According to the present invention constructed as described above, the following remarkable effects are achieved, and its industrial value is extremely high.

(1) A knitted fabric that is bulky, has fluff on the surface, and has a spun yarn-like appearance and texture can be obtained.

(2) Since these fluffs have different cross-sectional shapes and finenesses, the knitted fabric has a deep aesthetic quality.

(3) These fluffs are extremely fine and feel warm to the touch.

(4) These fluffs are well retained in the knitted fabric, so pilling is less likely to occur.

(5) Unlike conventional methods, the above-mentioned knitted fabric can be obtained with high productivity without thread cutting or other process troubles.

(6) The fluff distribution is uniform, and the length can be controlled by stretching, false twisting, and chemical treatment conditions.

Example 1 Intrinsic viscosity i 1. 10 nylon 6 as the core component and polyethylene terephthalate with an intrinsic viscosity of 0.73 as the sheath component, the discharge volume ratio of the gear pump is 1:2, and the spinning temperature is 290.
'C, Composite spinning at a winding speed of 100,077 L/min.
Obtain an undrawn yarn with a cross section as shown in figure a, and convert this undrawn yarn into 8
The yarn was stretched 3.0 times at 5°C, heat treated on a hot plate at 150°C, and wound at 600 m/vtin to obtain a drawn yarn of 85d/15f.

In the cross section, some cracks were observed in the sheath, but no splitting had occurred.

Next, the obtained drawn multifilament was heated at 190°C with a first heater using an LS-6 false twister manufactured by Mitsubishi Heavy Industries, Ltd.
2nd heater 230'C, 1st overfeed O%,
2nd Overfeed 12.5 Hiroshi When false twisting was performed under the conditions of a spindle rotation speed of 300,000 rpm and a twist number of 3300 T/M, one filament was formed into four filaments with different fineness and shape as shown in Figure 2. Divided into thin filaments of books.

When the thus obtained split marte crimped yarn was knitted into a tube knit and treated with a 10% caustic soda aqueous solution at 80°C for 60 minutes, the weight loss rate of the polyester, which is the sheath component, was 30% by weight. Many fine fluffs were observed on the surface.

These fluffs were well retained in the tubular knitted fabric and did not fall off even when rubbed.

When the tubular knitting was unwound and the cross section of the filament was observed under a microscope, it was found that these fluffs were composed of fluffs with various cross-sectional shapes and finenesses, and the fineness range was 0. Ol~
It was 2d.

In addition, the treated tubular knit had deep aesthetics and a warm texture, exhibiting a spun yarn-like appearance and texture.

Comparative Example When the drawn yarn obtained in the example was directly knitted into a tube without false twisting and treated with a 10% caseinida aqueous solution at 80°C for 80 minutes, the weight loss rate of the polyester as a sheath component was 30 fb, the same as in the example. Many fine fluffs were observed on the surface of the tube knit, but when the surface of the tube knit was rubbed, these fluffs fell off as fluff.

It also lacked bulk and had an unsatisfactory spun yarn-like appearance and texture.

Example 2 Nylon 6 with an intrinsic viscosity of 1.20 is used as the core component, polyethylene terephthalate with an intrinsic viscosity of 0.65 is used as the sheath component, the discharge ratio of the gear pump is 1:2, the spinning temperature is 280°C, and the winding speed is 1000 m/min. Composite spinning was performed to obtain an undrawn yarn having a cross section as shown in Fig. 1b, and this undrawn yarn was heated at 85°C for 28 hours.
Stretch it twice and heat treat it on a hot plate at 150'C.
A drawn yarn of 85 d/15 f was obtained by winding at 0 ml min.

Although cracks were observed in some parts of the cross section, no splitting had occurred.

Then, the obtained drawn multifilament was made into LS-6
Using a false twister [manufactured by Mitsubishi Heavy Industries (3)], the first heater 1
90'C, second heater 230°C, first overfeed O, second overfeed 125°, false twisting spindle rotation speed 300,000 rpm, number of twists 3300 T/M. As shown in the figure, one filament was divided into four thin filaments each having a different fineness and shape.

When the thus obtained split marte crimped yarn was knitted into a tube knit and treated with a 10% caustic soda aqueous solution at 80°C for 45 minutes, the weight loss rate of the polyester, which is the sheath, was 30% by weight. Many fine fluffs were observed on the surface.

These fluffs were well retained in the tubular knitted fabric and did not fall off even when rubbed.

When the tubular knitting was unwound and the cross section of the filament was observed under a microscope, it was found that these fluffs were composed of a variety of different cross-sectional shapes and finenesses, and the fineness range was 0.01.
It was ~2d.

In addition, the treated tubular knit had deep aesthetics and warm texture, and had a spun yarn-like appearance and texture.

[Brief explanation of the drawing]

Figures 1 a-c are fiber cross-sectional views showing various cross-sectional shapes of undrawn yarns used in the present invention, and Figure 2 is fiber cross-sectional views showing various cross-sectional shapes of undrawn yarns used in the present invention, and Figure 2 is fibers obtained by drawing and false twisting the undrawn yarns of Figure 1 a FIG. 3 is a fiber cross-sectional view of a split malte crimped yarn obtained by drawing and false twisting the undrawn yarn of FIG. 1b.

Claims (1)

[Claims] 1 Two types of polymers with poor mutual affinity are arranged in a core-sheath type, and in the cross section of the fiber, at least one of the core and sheath has 3 to 7 irregularities on the outer periphery, and the core has The undrawn composite yarn, which accounts for 20 to 70% of the fiber cross-sectional area, was drawn and false-twisted to separate the core and sheath and subdivide the sheath, followed by knitting and weaving. After that, the sheath is treated with a drug that dissolves or decomposes only the sheath, and the sheath is removed.
A method for producing a special knitted fabric, characterized in that a large number of fluffs having different cross-sectional shapes and finenesses are developed on the surface of the knitted fabric by removing 50 weight φ.