JP2586483B2 - Composite spun yarn for protective clothing against blades - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application fields] In the fields of metal press working, meat processing, glass working, can making, and the like, sharp tools such as cutting tools, sharp cutting edges of processed products, etc. Protective clothing such as safety gloves and safety work clothes is used for the purpose of protecting garments. The present invention relates to a composite spun yarn used as a material for such protective clothing and the like, particularly a protective clothing against blades which exhibits excellent protective properties, is hard to slip, is flexible, does not adversely affect workability, and has a bulky feel. The present invention relates to a composite spun yarn for use.

[Prior art] As a composite spun yarn having a high strength and a high elastic modulus, a composite spun yarn (generally referred to as a core yarn) formed by superposing a short fiber on a synthetic fiber multifilament yarn and twisting the same is used.
44-16825, 54-13537, 54-27449, 55-17140, etc., a composite spun yarn obtained by twisting a synthetic multifilament yarn and a short fiber in a mixed state (hereinafter referred to as mixed fiber). Composite spun yarn) is known.

It is said that these core yarns and blended composite spun yarns are superior in strength, etc. due to the use of synthetic fiber multifilaments compared to spun yarns consisting only of short fibers, but they have protection against sharp blades etc. In this respect, it does not yet have sufficient performance. In other words, core yarns and mixed fiber composite spun yarns were originally considered for general clothing, and because they were relatively strong, their applications were expanded to protective clothing, etc., but from the viewpoint of blade protection. At first glance, it is not a completed product, and there is room for improvement.

[Problems to be Solved by the Invention] From the standpoint of improving the protection against cutting knives only, the synthetic fiber multifilament yarn, which is responsible for the improvement of the strength and the like, is replaced with a fiber having a higher strength and a higher elastic modulus. Although it is possible to make a policy, it is considered that simply improving the material strength and elastic modulus has little effect on the protection against blades, and in addition, specific conditions are acting. That is, even if a synthetic fiber multifilament yarn having a higher strength and a higher elastic modulus is used, the composite spun yarn prototyped under the same conditions as the core yarn and the mixed fiber composite spun yarn still has insufficient strength and elastic modulus as a spun yarn. It was not sufficient, and the anti-knife protection was not satisfactory, and was unsuitable as a material for protective clothing.

The present invention has been made in view of such circumstances, and has been completed as a result of repeated studies on the spinning conditions in addition to the constituent materials.

Means for Solving the Problems The composite spun yarn for protective clothing of the present invention is a composite spun yarn composed of a synthetic fiber multifilament yarn and a short fiber, and the synthetic fiber multifilament yarn has an ultrahigh molecular weight. Made of polyethylene filament yarn and at least
It has a tensile strength of 20 g / denier and a tensile modulus of at least 500 g / denier, and the cross section of the composite spun yarn exhibits a mixed state of a synthetic multifilament yarn and a short fiber, and a twist coefficient K, The point is that the mixing ratio X (%) of the short fibers and the short fibers is in the range shown by the following formula.

[Action] The present inventors have conducted various studies on spinning conditions and found that the twisting coefficient and the mixing ratio of short fibers have a great effect on the protection against blades.

In other words, although a relatively high twist coefficient was conventionally applied for the purpose of preventing the extraction of short fibers, it is clear that a lower twist coefficient is preferable from the viewpoint of protection against sharp blades. It became. However, since it is necessary to prevent the short fiber from being pulled out, the twisting coefficient may be reduced as far as possible without adversely affecting the drawing out of the short fiber.

The present invention attempts to determine the lower limit of the twisting coefficient from such a viewpoint, but since the lower limit means a limit value at which the extraction of the short fiber does not occur, it is affected by the mixing ratio of the short fiber. There is a characteristic, and as the mixing ratio of the short fibers is smaller, the entanglement between the short fibers is reduced, and the extraction is more likely to occur.
That is, the twisting coefficient needs to be increased as the mixing ratio of the short fibers is smaller. When the multi-filament multifilament yarn and the short fiber are present in a mixed fiber state (that is, mixed fiber composite spun yarn), the short fiber is shorter than when the multi-filament yarn is present in a non-fiber mixed state (that is, core yarn). It is also clear that the twisting coefficient is hard to be removed and the twist coefficient can be set lower. Then, the lower limit of the twist coefficient was determined based on the above findings, and the relationship represented by the following equation (1a) was obtained.

However, K _L : the lower limit of the twisting factor X: the mixing ratio of short fibers 15 ≦ X ≦ 50 On the other hand, the upper limit of the twisting factor is determined from the viewpoint of the protection against the blade. That is, when the twisting coefficient is increased, the short fibers are less likely to come off, but the protection against sharp blades is deteriorated as the twisting coefficient is increased, and as the mixing ratio of the short fibers is increased. As a result of obtaining the upper limit of the twisting coefficient based on such knowledge, the relationship of the following equation (1b) was obtained.

However, K _U : the upper limit of the twisting factor X: the mixing ratio of short fibers 15 ≦ X ≦ 50 The reason why the higher the twisting factor deteriorates the protection against blades from the results is as follows. It was found that there was a decrease in physical properties such as strength.

That is, the influence on the tensile strength ratio and the degree of pulling out the short fiber by variously changing the twist coefficient under the following conditions was examined,
The results shown in Table 1 were obtained.

(Experimental conditions) For ultra-high-strength polyethylene multifilament yarn with a tensile strength of 35 g / d, a tensile modulus of elasticity of 1200 g / d, and a 300 d / 240 filament manufactured from high molecular weight polyethylene having a molecular weight of 2,000,000
1 denier, a composite spun yarn mixed with 30% of polyethylene terephthalate short fiber having a cut length of 38 mm was used.

Next, when the composite spun yarn having a twist coefficient of 3.0 was defibrated and the monofilament of ultra-high-strength polyethylene fiber was taken out, the tensile strength was examined and compared with the ultra-high-strength polyethylene fiber raw yarn, the results shown in Table 2 were obtained. Was.

As shown in Table 2, there is no significant difference in the tensile strength between the monofilament obtained by opening the composite spun yarn having a twist coefficient of 3.0 and the original monofilament. That is, as shown in Table 1, the tensile strength ratio sharply decreases with an increase in the twisting coefficient. However, according to the results in Table 2, a change (damage rate) occurs in the filament itself due to twisting. It can be seen that this is simply due to the twist structure (reduction in the strength utilization rate due to twist strain). It is considered that such a decrease in physical properties due to twisting has a considerable effect on the protection against blades. Although not confirmed experimentally, the fact that the apparent hardness of the composite spun yarn surface increases with an increase in the twisting coefficient and the impact resistance deteriorates also contributes to this. It is estimated to be.

As described above, the mixing ratio of short fibers greatly affects the upper and lower limits of the twisting factor, and is a factor that affects the protection against blades, but on the other hand, the feeling of wearing and appearance as clothing are also overlooked In addition, characteristics such as texture are required, and when used for safety gloves and the like, characteristics such as good flexibility and stable work are also required. The blending ratio of short fibers is a factor that has a great effect on these properties.The higher the blending ratio, the more the texture becomes similar to that of spun yarn, the softer it becomes. Blade protection is reduced. Therefore, it is necessary to determine the upper limit of the mixing ratio in consideration of the blade protection performance. More specifically, when the mixing ratio of the short fibers exceeds the upper limit, since the tensile strength of the composite spun yarn often depends on the synthetic fiber multifilament yarn having a low elongation, the composite spun yarn has a large thickness. The tensile strength is reduced, and the protection against blades is significantly reduced. On the other hand, if the mixing ratio of the short fibers is too small, the yarn becomes a filament-like composite spun yarn, losing the flexibility and feel of the spun yarn. Defects such as slipperiness are exposed.

For this reason, in the present invention, the mixing ratio (X) of the short fibers is 15
It is specified in the range of ~ 50%. More preferably, the mixing ratio (X) of the short fibers is desired to be 20 to 50%, and the twist coefficient (K) defined by the upper and lower limits is preferably 2 to 3, more preferably 2.5 to 3. desired.

In the present invention, it is necessary to use an ultrahigh molecular weight polyethylene multifilament yarn having high strength and high elastic modulus as the synthetic fiber multifilament yarn. More specifically, such a high tenacity / high modulus yarn is a multifilament yarn having a tensile strength of at least 20 g / d and a tensile modulus of at least 500 g / d. The ultra-high strength polyethylene multifilament yarn can be produced as follows. Once the high molecular weight polyethylene is dissolved in the solvent, it is cooled to form gel particles that occlude the solvent,
Next, the gel granule is supplied to the gel fiber spinning step by dispersing or dissolving in the same or the same solvent as the solvent occluded in the gel granule, and supplying the spun yarn discharged from the spinneret in a solvent-containing state. , And subsequently hot-drawn continuously and wound up to obtain an ultra-high-strength polyethylene multifilament yarn.

On the other hand, the short fibers blended with the multifilament yarn are not particularly limited, and include polyester fibers and cotton fibers. If the short fibers are also made of high-strength and high-modulus fibers, their strength and elasticity are improved. Thus, a composite spun yarn having more excellent protection against blades can be obtained. Examples of the composite spun yarn of such a preferable combination include a composite spun yarn composed of an ultra-high-strength polyethylene multifilament and an ultra-high-strength polyethylene staple, and a composite spun yarn composed of an ultra-high-strength polyethylene multifilament and a wholly aromatic polyamide staple. No.

In addition, applying a coating agent or a non-slip agent to the surface of the composite spun yarn of the present invention or its woven fabric is also an effective auxiliary means for achieving the object of the present invention.

[Example] Example As shown in Fig. 1, the fiber was opened by being led to an electric fiber opening device 6.
Ultra-high-strength polyethylene filament yarn B with 300 denier / 240 filaments (tensile strength 32 g / denier, tensile modulus 1300 g / denier), and 1-denier 38 mm long polyethylene terephthalate staple A with 7 g / denier strength
Are superimposed immediately before the front roller 1 to form an 80% ultra-high strength polyethylene fiber multifilament yarn and a 20% polyethylene terephthalate short fiber yarn.
To prepare a mixed fiber composite spun yarn F (No. 1). The tensile strength, tensile modulus, and the like of this mixed fiber composite spun yarn were as follows.

Denier 410 denier Tensile strength 7.2 kg Tensile strength 17.6 g / denier Tensile modulus 340 g / denier When the object was worn without slippage when grasped, it had a good feeling like a warm spun yarn. The protection (cut resistance) of the glove against sharp blades and the like was good (evaluation ◎).

 Evaluation of cut wound resistance was performed as follows.

 FIG. 2 shows a schematic diagram of the measurement method.

The upper end of the sample S having a sample width of 50 mm is fixed, spread in the direction of gravity, suspended vertically to the ground, and set with a load W applied to the lower end of the sample so that the weight of the sample becomes 0.1 g per unit area. As shown in FIG. 2, a rotating bar 5 having a feather razor blade 4 attached to both sides of the surface was rotated and collided. Here the feather razor blade 4
In detail, the blade part of the
mm, and the rotation speed of the rotating rod was set to 10 rpm. The cut state of the sample 5 minutes after the start of rotation of the rotating rod 5 with a blade was evaluated.

In addition, the feather razor blade is carbon steel blade thickness 0.245mm, blade length 39mm
Was used.

The rotating bar 5 with a blade was set to have a distance of 150 mm from the center of the rotating bar to the tip of the shaving blade.

 The evaluation was as follows.

◎: Not cut at all ○: Almost no cuts △: Slight cuts ×: Broken Comparative Example 7 g of a polyethylene terephthalate multifilament yarn having a tensile strength of 150 denier / 75 filaments of 7.5 g / denier and a tensile modulus of 160 g / denier / Denier, 1 denier, 38 mm long polyethylene terephthalate short fiber yarn, superimposed just before the front roller in the same manner as in the example, a twist consisting of polyethylene terephthalate multifilament 80%, polyethylene terephthalate short fiber yarn 20% Twisting was performed at a coefficient of 2.5 to produce a specific mixed fiber composite spun yarn (core yarn) (No. 4). The performance was as follows.

Denier 190 denier Tensile strength 0.9 kg Tensile strength 4.7 g / denier Tensile elastic modulus 34 g / denier However, when worn, it had a good touch with a warm taste, but had poor protection against sharp blades and the like (evaluation: x).

Next, in accordance with the above-mentioned production method, various spun yarns are produced by variously changing the configurations of the multifilament yarn and the short fiber,
When the correlation between each short fiber mixing ratio (X) and twisting coefficient (K) and its evaluation characteristics was examined, Table 3 (A), (B),
(C), (D) and the results shown in FIG. 3 were obtained. still,
In the table, "KKS" means ultrahigh molecular weight polyethylene multifilament, and "composite spun yarn" means "mixed fiber composite spun yarn".

In the area indicated by the oblique lines in FIG. 3, a mixed fiber composite spun yarn having good blade protection properties and short fiber removal resistance was obtained. And it turned out that this area is represented by the range shown by the following formula.

[Effects of the Invention] The spun yarn for anti-knife protective clothing of the present invention is constituted as described above. By weaving and knitting the spun yarn, the spun yarn has a soft, spun yarn-like feel and has a moderate slip resistance. In addition, various types of clothing having excellent protection against sharp blades can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing a composite spun yarn manufacturing apparatus according to the present invention, FIG. 2 is an explanatory view showing a method of measuring cut resistance, and FIG. 3 is a short fiber mixing ratio, twist coefficient and cut resistance evaluation. 6 is a graph showing the relationship of. 1 ... front roller, F ... mixed fiber composite spun yarn

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-2703 (JP, A) JP-A-60-162825 (JP, A) JP-A-49-36944 (JP, A) 28641 (JP, B2)

Claims (1)

(57) [Claims] 1. A composite spun yarn comprising a synthetic fiber multifilament yarn and a staple fiber, wherein the synthetic fiber multifilament yarn comprises an ultra-high molecular weight polyethylene filament yarn and has a tensile strength of at least 20 g / denier and at least 500 g / denier. The composite spun yarn has a tensile modulus of denier, and the cross section of the composite spun yarn shows a mixed state of a synthetic multifilament yarn and a short fiber, and the twist coefficient K and the mixture ratio X (%) of the short fiber are A composite spun yarn for protective clothing against cutlery, characterized by being in the range shown by the following formula.