KR100775702B1 - Thermal-resistant, flame-retardant and non-asbestos fiber composition - Google Patents

Abstract

A non-asbestos composite fiber is provided to realize the improvement in flame-resistant property, heat-resistant property, and strength, by producing the composite fiber to contain carbon fibers as well as aramid fibers and silica fibers. A non-asbestos composite fiber comprises 20-70 wt% of aramid fibers, 10-70 wt% of silica fibers, and 10-20 wt% of carbon fibers. The non-asbestos composite fiber is woven or knitted in a tape type or a tube type. The non-asbestos composite fiber is used for covering materials for a tube or a rubber hose, a welding flame receiving sheet, fireproof and heatproof curtain, a heat insulator, sound absorbing materials, surface materials for a duct, a safeguard device, fighting clothing, or welding clothing.

Description

Resistant and flame-retardant and non-asbestos fiber composition,

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing changes in elongation and strength retention by heat treatment in air of a composite fiber according to the present invention. FIG.

FIG. 2 is a graph showing changes in heat treatment time and physical properties of the composite fiber according to the present invention at a high temperature.

Fig. 3 is a graph showing changes in strength of the composite fibers and various fibers of the present invention after heat treatment at a high temperature. Fig.

4 is a graph showing the shrinkage ratio and weight reduction ratio of the composite fiber according to the present invention after high-temperature heat treatment.

Figure 5 shows the strength-elongation curves for a 100% carbon fiber yarn.

Figure 6 shows the strength-elongation curves for yarns mixed with 30/70% carbon / wool.

Figure 7 shows the strength-elongation curves for an aramid / silica / carbon fiber 40/50/10 spinning yarn.

The present invention relates to heat-resistant and flame-resistant asbestos-free composite fibers, and more specifically, to harmless human bodies, by containing a certain proportion of carbon fibers in addition to aramid fibers and silica fibers as substitutes for asbestos and glass fibers. As well as to a composite fiber having remarkably improved heat resistance, salt resistance and strength.

Humans who have dominated the earth by using tools and tools have used the usefulness of fire in many aspects, but have made a lot of efforts to prevent them against disasters of fire. In particular, the development of flame-retardant and heat-resistant fibers is an aspect of the fight against humanity. In the decades since modernization, the demand for flame retardant and heat resistant fiber has steadily increased, and the flame retardant fiber has been researched centered on the interior, and the heat resistant fiber has been researched centering on the protective clothing.

A processing method has also been developed to prevent or inhibit the fibers from sparking and burning themselves when the flame is brought into contact with the flame and the flame is removed as flame-retarding and fireproofing treatment for the fiber. Traditionally, flame retarding and fireproofing of fibers have been developed mainly around cellulose fibers, and the mechanism for this has been studied.

In 1983, after the death of 23 Canadian Airlines DC-9 accidents at Cincinnati Airport, there was a growing voice in the seat seats of the aircraft seat, and this was legislated in the United States in November 1984, to be. In other words, in the United States in October 1987, the seat of the aircraft seat was fully flame retarded, and in Japan in August 1988, it was fully implemented.

In addition, seats for transportation such as trains, buses, and passenger cars, as well as theaters and public institutions are becoming the subject of choice.

Especially in Korea, after the subway fire accident in Daegu in January 2003, the use of flame retardant fibers or flame retardant materials in subway seat sheets and interior materials is obligatory.

On the other hand, asbestos is a typical mineral fiber produced naturally, and is an industrial material that has been used for a wide range of purposes for many years due to its non-flammability and low price. In 1985, the demand was great, with global consumption of 4.1 million tons. However, since the harmful effects of asbestos fibers on the human body, that is, the release of fatal harmful substances that cause cancer and asbestosis have been revealed, the usage amount has been reduced mainly in the United States and Japan, and since then, Various studies have been conducted.

In addition to asbestos, there are rock surfaces and glass fibers. They are currently woven with tapes and woven fabrics and are used as spatter sheets, fireproof and heat-insulating curtains, covers, thermal insulation materials, insulating materials, sound absorbing materials, and surface materials for ducts. However, since glass fibers are dusty and irritating to the skin, The use of the aramid fiber has been regulated, and a composite fabric obtained by mixing glass fiber as a reinforcing material with aramid fiber has been found, but it is still pointed out that dust is generated due to the glass fiber.

Accordingly, there has been a constant demand for the development of composite fibers excellent in heat resistance and salt resistance without using asbestos and glass fibers and having high strength. Accordingly, the present inventors have repeatedly studied on asbestos substitute fibers. As a result, It was completed.

It is an object of the present invention to provide a conjugated fiber having remarkably improved heat resistance, salt resistance and strength by containing a certain proportion of carbon fibers in addition to aramid fibers and silica fibers.

It is another object of the present invention to provide a non-asbestos conjugate fiber which is made of a non-asbestos sheet and which does not generate harmful dust and does not use any glass fiber, has no skin irritation and slippery, and is excellent in heat insulation, warmth and sound absorption.

The non-asbestos composite fiber of the present invention comprises 20 to 70% by weight of aramid fibers, 10 to 70% by weight of silica fibers, and 10 to 20% by weight of carbon fibers.

The aramid fiber is an aromatic polyamide fiber excellent in tensile strength, toughness, high strength and high modulus. It is a thin thread with a thickness of about 5mm, but it has a strong force enough to lift a car of 2t. It is not burned or melted. It must be over 500 ℃ before it can be carbonized, so bulletproof jackets and bulletproof helmets, golf clubs, And internal aggregates such as Boeing 747 have useful properties enough to use FRP reinforced with this fiber.

In addition, silica fiber is a heat-resistant fiber that can withstand continuous use temperature of 1,000 ℃ and instantaneous use temperature of 1,650 ℃. It is harmless to human body, has no skin irritation, has good chemical resistance and is electrically insulated and has been used as a substitute for asbestos.

However, the silica fiber is excellent in heat resistance, but the fiber is severely broken and the bending strength and tensile strength are very weak. When 100% of the silica fiber is put into a carding machine, all of the fibers are broken and can not be spun.

To overcome this difficulty of spinning, aramid fibers are mixed, but aramid fibers have a disadvantage of high unit cost.

When the aramid fiber and the silica fiber alone are mixed to produce the composite fiber, the mixing ratio of the aramid fiber should be less than 20% when the aramid fiber is 80% or more (all the weight% or less). In this case, the strength of the product is excellent The low-temperature mixing of the silica fibers deteriorates the heat resistance, making it unsuitable as a heat-resistant product, and also raising the unit cost of the product.

On the contrary, when the aramid fiber is less than 20%, the silica fiber should be mixed in an amount of 80% or more. In this case, if the mixing ratio of the silica is increased, the fiber does not spin due to the destruction of the silica fiber.

In addition, in the case of a composite fiber obtained by mixing aramid fiber with 40% of silica fiber and 60% with silica fiber, spinning may occur but loss of raw material for the product is increased due to destruction of silica fiber. It is also not preferable that the salt resistance is proportional to the loss ratio and thus the salt resistance to fire is reduced.

However, the above problem can be solved by mixing 10 to 20% by weight of the carbon fibers with the two fibers. That is, the carbon fiber is excellent in heat resistance, and not only does the fiber fail less than silica, but also has excellent tensile strength of the fiber.

Table 1 below shows the results of a comparison of the fiber loss ratios of carbon fiber blended and non-blended fiber blends. That is, when the total weight of the mixed fibers was 50 kg, the loss of fibers during spinning was compared, and it was found that the loss of aramid / silica / carbon fiber was significantly lower than that of mixed fibers composed of only aramid / silica.

Fiber mixing ratio Gross weight (kg) Weight without losing (kg) Loss rate (%) Aramid Silica Carbon fiber 60% 20% 20% 50kg 49.7kg 0.7% 40% 40% 20% 50kg 49.0kg 2.0% 20% 60% 20% 50kg 48.0 kg 4.0% 80% 20% 50kg 49.7kg 0.7% 40% 60% 50kg 46.5kg 7.0% 20% 80% 50kg Not spinnable Not spinnable

Table 2 below shows the results of experimental measurements of the fire resistance of the composite fibers of the present invention. The composition ratio of the mixed fibers was experimentally manufactured by the ratio of aramid / silica / carbon fiber 40/50/10. The results of Table 2 show that the composite fiber of the present invention satisfies all of the flame retardancy standards of the Korean fire department.

Flammability test result Brine Time (s)     0     0     0     0     0  // 0 Time remaining (s)     0     0     0     0     0  // 0 Carbonization distance (cm)    0.7    0.5    0.6    0.7    0.6  // 0.6

The method for producing the conjugate fiber of the present invention is as follows.

1. Horn surface process

First, 20 to 70% by weight of aramid fibers, 10 to 70% by weight of silica fibers and 10 to 20% by weight of carbon fibers are mixed.

In other words, blowing & picking, which is the initial step of the spinning process, generally starts with a mixing process in which various kinds of raw cotton (aramid / silica / carbon fiber) are mixed according to the purpose of discharging, A cleaning process to remove impurities such as an opening process, a nep, a nep, and a short fiber to separate the fiber bundle into small tufts, A lap formation process (Mixing machine RPM: 220 RPM) is performed to create a lap with thickness and width.

2. Carding process

The purpose of carding as carding is to separate the fibers into completely free-flowing fibers by combing the fibers, since the wraps made in the process of horn-rubbing have become carded and sealed, So that the inclusion can be thoroughly removed so that the stretching operation can be smoothly performed in the next step to enable the formation of the yarn.

In other words, combing the fibers through the cotton process, separating them into individual fibers (combing, carding), removing the fibers, short fibers, and neps from the fibers, and stretching the fibers to some extent to straighten and parallelize (Carding machine RPM: 28 RPM, Gauge: 0.3 mm) to make fiber of uniform thickness.

3. Combining process

Although the fine face process removes a large amount of textiles and staple fibers from the surface process, it can not be removed sufficiently. If a lot of staple fibers are contained, it causes a non-uniformity of the draft in the subsequent process, Therefore, it is intended to remove the short fibers through the combing process and to discharge the fine yarn of uniform quality and good quality.

In other words, it is possible to remove the noil which causes the draft inhomogeneity, to remove the residual material on the sphere sliver, and to combine the fibers and to combine the fibers in a more parallel state, It is the process of making the fibers of uniform thickness by polymerizing and stretching the cotton wraps (forming the sphere of the face).

4. Drawing process

The sliver produced by the process of the somen or the pure surface has floating between the sliver and the sliver depending on the weight fluctuation of the wrap or the floating amount of the somen surface when the sliver is horny. In the case of the somen sliver, the individual fibers of the sliver were combed but not completely straightened, not oriented, and not arranged in parallel. When the yarn is made of a sliver having a weight floating or a low degree of arrangement, the fluctuation of the thickness of the yarn becomes large, resulting in a non-uniform yarn and a lot of fine hair.

Therefore, the soft-spinning process is the last step of correcting the cause of such an irregularity in the spinning process. The purpose of this process is to generally combine 6-8 strands of sliver to increase uniformity, to stretch the polymerized sliver Drafting the fibers by parallelizing them, blending yarns by mixing different types of fibers as needed, and producing more uniform drawing slivers (forming a sliver sliver).

5. Roving process

In order to make yarn from sliver produced in the soft process, there are many difficulties in terms of quality such as drafting mechanism, operational problems and homogeneity. Therefore, the sliver should be stretched to reduce the linear density to a thickness that can make the yarn. Therefore, the sliver is stretched to a thickness that can be discharged from the processing plant to the required yarn to reduce the thickness (drafting process), give a slight twist process, and wind the woodblock to facilitate handling as a subsequent process & building process).

6. Spinning process

The spinning process is a process in which the sliver of the irradiation process or the softening process produced in the spinning process is stretched to a desired thickness, the yarn is discharged by applying a suitable twist, and the spinning process is performed on the spinning mill. The spinning or sliver is drafted (Twisting), and spinning the yarn around the spindle to form a cop (Spinning machine RPM: 8000 RPM, twisting: 10T).

7. Winding process

In the winding process, 10 to 15 yarns produced in a square are connected to each other as needed, and the yarns are wound in a long and continuous yarn to lengthen the unit length, remove various defects generated during the spinning process, This is a process for winding appropriate tension so that the proper shape and hardness can be obtained. This is to improve the quality by removing crystals of slabs, airspeeds, scabs, nepes and the like, And the knitting yarn is wound in the form of cheese to facilitate the handling. The knitting yarn of the knitting yarn suppresses the generation of fine hair, Waxing or oiling to smoothen the package and dyeing the package (package dyeing or cheese dyeing) to reduce the density of the yarn when winding a soft package (soft pac kage (Winding machine RPM: 7000 RPM).

The fibers made according to the above manufacturing method can be used for industrial materials, safety protectors, disaster prevention equipment, special work clothes, and other applications by weaving and knitting into a tape type, a tube type (loop type), and a fabric type. The industrial material can be coated on a pipe or a rubber hose to protect the pipe or the rubber hose and to obtain a heat insulation effect. The pipe can be used for various pipes such as pipes, fluid pipes such as gas and liquid, or bellows pipe It can be used as a coating. It can also be used for spatter sheets, fireproof and heat-insulating curtains, covers, insulation materials, insulating materials, sound absorbing materials, and surface materials for ducts. Examples of the above-mentioned safety protection and disaster prevention equipment include heat-resistant gloves, hoods, aprons, toys, gaiters, tapes for preventing burning of electric wires (underground cables), fireproof mats, household fire extinguishers, emergency fireproof pouches, and evacuation ropes. The above-mentioned special work clothes can be used for fire fighting clothes, heat insulating clothes, welding clothes, chemical clothes and the like. For the above-mentioned other uses, it can be used for a seat insulation layer of a seat, such as a curtain of a ship, a hospital, a theater, etc., or a seat seat of a subway.

The composite fiber of the present invention was found to satisfy the following salt tolerance test conditions.

① No combustion takes place when the oxygen concentration in the air is 20% ~ 30%.

② It does not melt or bond even if it touches direct flame.

③ Excellent resistance to spark.

Since the composite fiber of the present invention has the above three flame retardancy and heat resistance, it is possible to avoid the problem that the present non-flammable and flame-retardant synthetic fibers are adhered and fused to human body when they are exposed at high temperatures, do.

Table 3 shows the results of comparing various properties of the composite fibers (aramid / silica / carbon fiber 40/40/20 ratio) according to the present invention to asbestos fibers, glass fibers and wool. INDUSTRIAL APPLICABILITY The composite fiber of the present invention is excellent in workability such as spinning and service, has a drape and soft touch which are not possessed by asbestos or glass fiber, is easy to handle and has excellent thermal conductivity and has a thermal conductivity as high as that of wool.

Conjugated fiber Asbestos fiber Glass fiber wool Denier 1.1 to 2.0 d - - - diameter 10 to 12μ 1 to 2μ 12μ - importance 2.2 2.4 ~ 2.6 2.54 1.32 The tensile strength 64 g / d 10 to 24 g / d 9.6 g / d 1.0 to 1.7 g / d Fracture 0.9 to 1.1% 3 to 3.5% 0 25-30% Moisture content (RH 65%) 20% 2.0% 3.1% 16% Resistivity 10 ⁸ to 10 ¹⁰ Ω cm 10 ¹⁵ Ω cm 10 ¹² Ω cm - color Yellow White White Dyeable

1 to 4 show changes in physical properties when the composite fiber of the present invention is exposed to air at a high temperature. FIG. 3 shows the tensile strength change of the composite fiber of the present invention and various woven fabrics of rayon, glass fiber, asbestos, and Kevlar when exposed at a high temperature, which indicates that the composite fiber of the present invention is excellent.

Table 4 below shows the results of treatment (30 占 폚, 24 hours) of typical chemicals to examine the chemical resistance of the composite fibers according to the present invention. The approximate resistance when not used for a long time in a strong alkaline was indicated.

density Strength retention rate Retention rate Sulfuric acid 40 60 90 Phosphoric acid 40 90 110 Acetic acid (nitric acid) 40 50 20 Acetic acid (nitric acid) 40 90 110 Hydrochloric acid 10 80 130 Ammonium hydroxide 20 80 120 Sodium hydroxide 10 30 100 Dimethylformamide 100 110 110 benzene 100 110 110 Ethyl alcohol 100 110 110 Carbon tetrachloride 100 110 100 Acetone 100 110 120

5 to 7 show tensile strength and elongation tests of three types of yarn fibers under the conditions of a sample length of 10 mm and a tensile speed of 10 mm / min using a tensile tester.

Figure 5 shows the S-S curves for spun yarns of 100% carbon fiber. It can be seen from the curve of the strain (mm) about the strength (Stress, kgf) that the average strength is about 2 mm between the maximum strength of 2.0 to 2.5 kgf.

Figure 6 shows the S-S curve for a yarn of carbon / wool 30/70. It can be seen from the curve of Strain (mm) against the Stress (kgf) that the maximum strength is maintained at the maximum strength of 0.4 kgf, and then the shape gradually slips.

7 shows the S-S curve for the silica / aramid / carbon fiber 40/50/10 spinning yarn of the composite fiber of the present invention. It can be seen from the curve of the strain (mm) against the strength (Stress, kgf) that the maximum strength is maintained at the maximum strength of 4.0 to 4.5 kgf, and the shape gradually slips.

From the above results, it can be seen that the composite fibers according to the present invention have the functions and advantages not found in conventional flame retardant fibers such as heat resistance and tensile strength.

The experimental results are shown in Table 5 below.

Evaluation items unit Development figures Flame Retardant PET complex Kevlar Oxygen index LOI 24.3 50.4 27.1 Water repellency % 45 to 65 95 to 110 90-100 The tensile strength N 789 1090 1443 Burst strength Kpa 2602 2788 3500 Air permeability Cm3 / cm2 / s 36.4 39.6 11.4

First, the composite fiber of the present invention is made of a non-asbestos surface, so that no carcinogens and toxic components are detected, so that it does not harm the human body.

Second, it has excellent heat resistance (heat resistance temperature 1,200 ℃, radiation temperature 1,600 ℃), excellent tensile strength and elongation, and no dust.

Third, there is an effect that the efficiency of work can be improved because there is no slip due to high moisture collection rate in the atmosphere.

Fourthly, it can be constituted by weaving and knitting in various forms and can be used for various purposes such as industrial materials, safeguards, disaster prevention equipment, special work clothes, and the like.

Claims (3)

A non-stone-surface composite fiber comprising 20 to 70% by weight of an aramid fiber, 10 to 70% by weight of a silica fiber, and 10 to 20% by weight of a carbon fiber. The non-asbestos composite fiber according to claim 1, which is woven or knitted in the form of a tape, a tube (loop) or a fabric. The non-asbestos composite fiber for use in a pipe or rubber hose according to claim 1, which is used for a covering material for a pipe or a rubber hose, a welding spark plug sheet, fireproofing and heat insulating curtain, heat insulating material, sound absorbing material, surface material for a duct, safety protection material, disaster prevention material, fire extinguisher, .

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