JPH0633536B2 - Polyvinyl alcohol-based spun yarn with excellent cut resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a polyvinyl alcohol spun yarn,
In particular, the present invention relates to a spun yarn having high strength and excellent cut resistance.

<Prior art> For general-purpose fiber materials such as polyester and nylon, in the field of protective clothing such as protective means and protective aprons, knitting yarns and weaving yarns that reduce the spun yarn count to increase the apparent bulk By taking measures such as increasing the number of threads, we have endeavored to improve the resistance to cuts and avoid problems with cut resistance.

However, when the above-mentioned countermeasures are adopted, the resulting protective clothing has a rugged feel, and the wearing sensation is extremely poor. Alternatively,
However, there still remain problems such as insufficient cut resistance.

Further, the conventional polyvinyl alcohol-based spun yarn has a low tensile strength of about 6 g / d. Therefore, the field of use of the spun yarn is mainly for clothing, and its development to industrial use was very limited.

Furthermore, the cut resistance, which is representative of cut resistance, represents the difficulty of cutting the blade, and when the cut resistance is small,
It is easy to suffer cuts and punctures when working with metal scraps, glass fragments, metal plates with return, etc. or meat dismantling work using a blade, and fulfills the specified purpose of protective clothing, protective equipment, etc. Can not do it.

In the case of the polyvinyl alcohol-based spun yarn, the cut resistance is as low as about 0.05 g / d, and therefore it has been difficult to develop the application to protective clothing, protective equipment and the like.

On the other hand, as a high-strength spun yarn, a spun yarn of para-aramid fiber is known. Although the cut resistance of the spun yarn is excellent at about 0.18 g / d, the spun yarn tensile strength is about 10 g / d, and the single yarn strength (about 22 g to d)
It cannot be said that it reflects the strength sufficiently compared to.

Furthermore, since the para-aramid fiber is originally composed of a rigid molecular chain, when the crimp is applied, the single filament yarn is easily damaged by buckling or the like. Therefore, the quality of the spun yarn composed of the crimped fiber is also inferior. In addition, para-aramid fibers have poor light (weather) resistance, especially UV resistance, and are not suitable for applications that are exposed to sunlight for a long time.

Therefore, for example, when it is used for protective gloves used outdoors, protective clothing such as protective apron, etc., there is a problem that performance is significantly deteriorated by sunlight, especially ultraviolet rays.

<Problems to be Solved by the Present Invention> An object of the present invention is to provide a spun yarn having high strength, cut resistance, and excellent quality by utilizing the characteristics of the high-strength polyvinyl alcohol fiber. is there.

<Means for Solving the Problems> That is, the present invention has the following configurations.

A high-strength polyvinyl alcohol-based crimped fiber having a single-fiber tensile strength of 13 g / d or more and a single-fiber average fiber length L (mm) satisfying the following formula (I), which is made of a polyvinyl alcohol-based polymer having a polymerization degree of 1500 or more. A polyvinyl alcohol-based spun yarn excellent in cut resistance, which is configured and has a spun yarn tensile strength DT of 5.0 g / d or more and a spun yarn cutting resistance ΔC of 0.08 g / d or more.

D × 12 ≦ L ≦ D × 50 (I) L: average fiber length (mm) D: average single yarn fineness (d) That is, polyvinyl in the polyvinyl alcohol-based spun yarn of the present invention (hereinafter referred to as the spun yarn of the present invention) The alcohol polymer is preferably a completely saponified linear chain, but a partially saponified type can also be used. The degree of polymerization needs to be at least 1500 or more, and if it is less than 1500, fibers having high strength and high cuttability cannot be obtained, and the spun yarn intended by the present invention cannot be obtained. The preferred degree of polymerization is 1
500 to 10,000, particularly preferably 3000
~ 5000. Generally, a higher degree of polymerization makes it easier to obtain high-strength fibers, but a degree of polymerization of 10,000 or more is not preferable because the production cost becomes a problem.

Further, as a spinning method, a tow spinning method, that is, a parlock method or a soft spinning method can be applied.
The tow spinning method is preferable because it is easy to obtain a spun yarn having high strength and excellent cut resistance.

Further, when the average fiber length of polyvinyl alcohol fiber (PVA fiber) is increased, the tensile strength of the spun yarn is increased, but the twist number of the spun yarn is decreased, and the cut resistance is lowered. Therefore, the average fiber length of the PVA-based fiber is D × 12 ≦ from the viewpoint of tensile strength, cut resistance and spinnability of the spun yarn.
L ≦ D × 50 (L: average fiber length (mm), D: average single yarn fineness (d)), and preferable average fiber length is D × 20 ≦ L
≦ D × 35.

In order to expand the application to industrial applications, the spun yarn tensile strength DT (g / d), which has a great effect on the tear strength of woven fabrics and knitted fabrics, is 5.0 ≦ DT, preferably 8 0.0 ≦ DT is required.

In addition, in order to develop applications for protective clothing such as protective gloves and protective aprons, it is required that the woven fabric and knitted fabric composed of spun yarn have excellent cut resistance, and therefore the cut resistance of the spun yarn is high. ΔC (g / d) should be kept at 0.08 ≦ ΔC, preferably 0.1 ≦ ΔC.

If this cut resistance is less than 0.8 g / d, the difficulty of cutting with respect to the blade will be reduced, and the protective clothing and protective equipment used in the work due to the metal chips and glass fragments generated by lathe processing etc. Make it easy to tear. as a result,
Cuts and punctures are more likely to occur, and the intended purpose of protective clothing, certain child equipment, etc. cannot be satisfied.

Here, the cut resistance of the spun yarn was determined by the following method.

That is, 2 so that the effective length is 5 mm at the center of the frame.
Hold the sample spun yarns of the book in parallel at an interval of 10 mm,
Between the two sample spun yarns, a blade of steel having a blade on two sides having an angle of 60 ° is vertically erected, and the sample spun yarn is cut when a load is applied to the cutting edge. Measure the weight to be loaded. Further, the measured load weight divided by the fineness of the sample spun yarn was taken as the cut resistance of the spun yarn.

If necessary, the spun yarn of the present invention may be mixed with other organic fibers and inorganic fibers in an arbitrary ratio.

Next, production examples of PVA-based fibers and spun yarns that can satisfy the requirements of the present invention will be described.

That is, in the present invention, a polyvinyl alcohol-based polymer having a degree of polymerization of 1500 or more is dissolved in dimethyl sulfoxide as a solvent to obtain a spinning dope. The obtained stock solution is extruded from the mouth of the spinneret, is dry-wet spun in a coagulation bath consisting of methanol, and is continuously washed, stretched and dried in a methanol solution to obtain an effective total draw ratio of 15 times or more. After heating and drawing as described above, hot water preheating is performed so that the fiber bundle temperature is 40 ° C. or higher and 70 ° C. or lower, and then crimping is applied by a crimping machine so as to have the specified crimping property, and at 80 ° C. or lower Thermal fixation. Then, a predetermined spun yarn is obtained by a normal staple spinning method.

Only by the above method, it becomes possible to obtain PVA-based fibers having high strength and excellent cut resistance, which are suitable for spun yarn.

In this case, the stretching conditions are such that the effective total stretching ratio is 15 times or more. This effective total draw ratio is 1
If it is less than 5 times, the target spun yarn properties, especially tensile strength DT
Of 5.0 g / d or more cannot be obtained.

Further, the preferable temperature as the ambient temperature during stretching is 220
It is in the range of to 260 ° C. By maintaining this temperature range, it is possible to more easily perform the drawing with an effective total draw ratio of 15 times or more, and the desired fiber having high physical properties can be obtained.

As a method of preheating the fiber bundle with warm water, any method may be used, such as a hot water bath immersion method or a shower method, as long as it is a method for obtaining the required fiber bundle temperature using substantially warm water. Needless to say, it may be mixed.

Further, when crimping, any method may be used as long as it does not substantially damage the fiber such as buckling. Mechanical crimping using a press type crimping machine is preferable.

After heat setting, the necessary finishing oil is added, and the tensile strength of the spun yarn,
From the viewpoint of cut resistance, the average fiber length of PVA-based fibers is D × 1.
2 ≦ L ≦ D × 50 (L: average fiber length (mm), D: average single yarn fineness (d)), preferably cut with a cutter or the like so that D × 20 ≦ L ≦ D × 35 Get raw cotton.

Here, the effective total draw ratio is the take-up speed after dry heat drawing divided by the take-up speed at the coagulation bath.

The spinning method may be any method used in the production of high-strength polyvinyl alcohol fibers, including dry, wet,
The effect of the present invention is not changed by the dry / wet method or the gel spinning method. The heating and stretching method may be liquid bath, wet heat, dry heat, hot plate, pin or hot roller stretching. Furthermore, after heat drawing, any heat treatment such as wet heat, dry heat, tension, constant length or relaxation may be performed.

The finishing oil agent may be applied in any step as long as it is after dry heat drawing.

<Examples> Hereinafter, the present invention will be described more specifically with reference to Examples.

Example 1 A raw yarn 150 obtained by dry-wet spinning of a spinning dope prepared by dissolving a completely saponified polyvinyl alcohol having a degree of polymerization of 2600 in a solvent, followed by continuous washing, bath drawing, drying and dry heat drawing.
0D / 600f (single yarn strength 20g / d, breaking elongation 4.6)
%) To form a tow of 108,000 D, and the average fiber length of 76 mm is 2 by the usual pearl lock type tow spinning method.
A 6th spun yarn was obtained.

The tow cutability by the pearl lock method was good, and there was no problem in the spinning process passability.

The obtained spun yarn was a good spun yarn without generation of nep or the like.

The tenacity of the spun yarn was 1349 g (strength 13.4 g / d) and the breaking elongation was 7.2%.

On the other hand, the cut resistance of the obtained spun yarn was 0.1 g / d, which was an excellent spun yarn having sufficient cut resistance for use in protective clothing.

Example 2 The same spinning dope as in Example 1 was dry-wet spun, and further the raw yarn obtained under the same spinning and drawing conditions was 1500D / 600f.
(Single yarn strength 20 g / d, breaking elongation 4.6%)
A tow of 108,000 D was obtained. The obtained tow was subjected to mechanical crimping under heating and then cut with a knife to a length of 51 mm to make cotton for spinning, and a 20-yarn spun yarn was obtained by an ordinary staple spinning method.

The tenacity of the spun yarn was 2605 g (strength 9.8 g / d), the breaking elongation was 8.5%, and the mechanical crimp did not lower the strength. In addition, there was no miscutting due to the reduction in the sharpness of the blade, and it was a good quality spun yarn with no occurrence of nep or the like.

The cut resistance of the obtained spun yarn was 0.11 g / d, and it was an excellent spun yarn having sufficient cut resistance for use in protective clothing.

Example 3 The same spinning stock solution as in Example 1 was dry-wet spun, and further, a raw thread 1500D / 400f obtained under the same spinning and drawing conditions.
(Single yarn strength 21 g / d, breaking elongation 4.8%)
A tow of 108,000 D was obtained. The obtained tow was subjected to mechanical crimping under heating and then cut with a knife to a length of 64 mm to make cotton for spinning, and a 20-yarn spun yarn was obtained by a normal staple spinning method.

The strength of the spun yarn is 2764 g (strength 10.4 g / d)
The cutting elongation was 7.9%, and there was no decrease in strength due to mechanical crimping. In addition, there was no miscutting due to the reduction in the sharpness of the blade, and it was a good quality spun yarn with no occurrence of nep or the like.

Furthermore, the cut resistance of the obtained spun yarn was 0.11 g / d, which was an excellent spun yarn having sufficient cut resistance for protective clothing applications.

Comparative Example 1 A raw yarn 150 obtained by dry-wet spinning of a spinning dope prepared by dissolving a completely saponified polyvinyl alcohol having a degree of polymerization of 1000 in a solvent, followed by continuous washing, bath drawing, drying and dry heat drawing.
0D / 600f (single yarn strength 10.6 g / d, breaking elongation 3.2%) was combined to obtain 108,000 D tow. The obtained tow was subjected to mechanical crimping under heating and then cut with a knife to a length of 51 mm to make cotton for spinning, and a 20-yarn spun yarn was obtained by an ordinary staple spinning method.

The tenacity of the spun yarn is 1197 g (strength 4.8 g / d) and the breaking elongation is 4.8%, which is lower than the spun yarn obtained from the raw yarn using polyvinyl alcohol having a polymerization degree of 1500 or more.

Further, the cut resistance of the obtained spun yarn was as low as 0.04 g / d, and the cut resistance was insufficient for industrial use and protective clothing.

Comparative Example 2 The same spinning stock solution as in Example 1 was dry-wet spun, and further, a raw thread 1500D / 400f obtained under the same spinning and drawing conditions.
(Single yarn strength 21 g / d, breaking elongation 4.8%)
A tow of 108,000 D was obtained. The obtained tow was subjected to mechanical crimping under heating and then cut with a knife to a length of 38 mm to make cotton for spinning, and a 20-yarn spun yarn was obtained by an ordinary staple spinning method.

The tenacity of the spun yarn was 2020 g (strength 7.6 g / d) and the breaking elongation was 5.2%, and the strength was decreased due to insufficient entanglement due to the short average fiber length.

Further, since the average fiber length is short, the fibers are often dropped during the spinning process, so that the spinning property is poor and a spun yarn of satisfactory quality cannot be obtained.

In addition, the cut resistance of the spun yarn obtained was 0.06 g / d, and the cut resistance was insufficient for use in protective clothing.

Comparative Example 3 The same spinning stock solution as in Example 1 was dry-wet spun, and further the raw thread obtained under the same spinning and drawing conditions was 1500D / 400f.
(Single yarn strength 21 g / d, breaking elongation 4.8%)
108,000 D tow was obtained. The obtained tow was subjected to mechanical crimping under heating, and then cut with a knife to a length of 200 mm to produce cotton for spinning, and a spun yarn of No. 29 was obtained by an ordinary staple spinning method.

The tenacity of the spun yarn was 2340 g (strength 8.8 g / d) and the breaking elongation was 5.2%.

However, the cut resistance of the obtained spun yarn was 0.04 g / d, and the cut resistance was insufficient for use in protective clothing.

<Effects of the Invention> By using the polyvinyl alcohol spun yarn of the present invention which has high strength and excellent cut resistance, it is possible to use a work or a blade for handling metal chips such as metal chips, glass fragments, and burrs. It is possible to inexpensively provide highly safe protective clothing, protective equipment, etc. suitable for work that involves the risk of suffering cuts, punctures, etc., such as meat slaughtering work.

Claims (1)

[Claims] 1. A single yarn tensile strength of 13 g / d or more, which is made of a polyvinyl alcohol polymer having a degree of polymerization of 1500 or more,
The single yarn average fiber length L (mm) is composed of high-strength polyvinyl alcohol-based crimped fibers satisfying the following formula (I), and the spun yarn tensile strength DT is 5.0 g / d or more and the spun yarn cut resistance ΔC. Is 0.08 g / d or more, and a polyvinyl alcohol spun yarn having excellent cut resistance. D × 12 ≦ L ≦ D × 50 (I) L: average fiber length (mm) D: average single yarn fineness (d)