KR100627675B1 - Method of making a sheath-core conjugate staple fiber and nonwoven - Google Patents

Abstract

The present invention is a composite spun fiber having a core component of nylon-6 relative viscosity of 2.3 to 3.2 and a polypropylene MF value of 8 g / 10 minutes to 20 g / 10 minutes. The present invention provides a method for manufacturing short fibers and nonwoven fabrics with excellent lightness, insulation, and flexibility due to the hollow between the super / core components formed through the interfacial separation between the supercomponent and the core components due to the difference in heat shrinkage and mechanical pressure during mechanical crimping.

Description

METHODS OF MAKING COMPOSITION AND MADE OF NON-WAVES USING THE SAME

)성분은 나일론 등 폴리아마이드 섬유를 사용하고 심성분은 폴리프로필렌(Polypropylene) 섬유를 사용하되, 이들을 초(

)성분과 심(芯)성분의 폴리머 비상용성과 폴리머간의 열수축 차이 및 기계권축시의 크림퍼 압력을 이용하여 초성분과 芯성분을 계면 박리시켜 상기 두 성분 사이에 중공이 형성되도록 함으로써 보온성이나 경량성 및 가격 경쟁력이 우수한 심초형 복합방사 단섬유를 제조하는 방법과 상기 단섬유로부터 제조된 부직포를 제공한다.The present invention relates to a method for producing a composite short fiber for making a nonwoven fabric for shoes and sundries and a nonwoven fabric made of the short fiber, more specifically,

Polyamide fibers such as nylon and polypropylene fibers are used for cores.

) The incompatibility of the component and the core component and the heat shrinkage difference between the polymer and the crimping pressure during mechanical crimping make the hollow component between the two components by interfacial separation between the component and the component. And it provides a non-woven fabric produced from the above-mentioned short fibers and a method for producing a cardiac hybrid composite short fiber with excellent price competitiveness.

Polyamide fibers such as nylon generally have good elasticity and abrasion resistance, and have great advantages in dyeing processability and chemical resistance, and especially when nonwoven fabrics made of the polyamide fibers are used for shoe manufacturing, It is excellent in properties such as flexibility, tearing and peel strength, so as not to be caught. Polyamide nonwoven fabric having such characteristics is also widely used as artificial leather. Artificial leather is a material obtained by wet impregnation and coating processing of polyurethane resin using the polyamide nonwoven fabric as a bubble, and in terms of its structure, functionality and flexibility, On the other hand, in terms of washability, stability, antibacterial, deodorization, dyeing fastness, etc., rather than natural leather, it is in the spotlight as an alternative material of the natural leather.

However, the polyamide nonwoven fabric has a disadvantage that the mechanical strength of the polyamide nonwoven fabric is expensive and the mechanical strength is lower than other synthetic fibers, and a technical solution for this has been demanded, and on the other hand, the demand level of consumers seeking more advanced artificial leather recently. In order to meet the above problem, in addition to the technical solution of the above problems, it is urgent to emerge the lighter fiber with excellent heat retention and softness.

The present invention has been proposed in view of the above problems and motives, and an object of the present invention is a composite fiber comprising a short fiber, a polypropylene having a low specific gravity and a low thermal conductivity as a core component, and a polyamide fiber such as nylon as a supercomponent. It has a fiber structure, but the interfacial separation between the supercomponent and the core component is carried out by the interfacial separation between the supercomponent and the core component by the polymer incompatibility of the supercomponent and the core component, the difference in heat shrinkage between the polymer, and the crimping pressure appropriately applied during the mechanical crimp. This formation provides a method for producing a composite spun short fiber having excellent heat retention and flexibility, and a nonwoven fabric prepared from the fiber.

Another object of the present invention is to prepare a composite spun short fibers inexpensive compared to the nylon short fibers while maintaining the overall strength by using polypropylene as a core component in the composite spun short fiber structure and a nonwoven fabric prepared from the fibers To provide.

The above objects are achieved by a method for producing short fibers provided according to the present invention. According to an aspect of the present invention, the method for producing short fibers includes polyamide, such as nylon, as a supercomponent, polypropylene as a core component, and a weight ratio (core component / supercomponent) of the supercomponent and the core component to 30 /. It is characterized by complex spinning in the range of 70 to 70/30.

The manufacturing method of the short fiber which concerns on this invention includes forming a hollow between the said sheath types by giving a crimper pressure 2.0K-6.0K at machine crimping, and separating a herbaceous component.

In addition, the method for producing short fibers according to the present invention is characterized in that the heat treatment temperature in the heat treatment step after the mechanical crimp is maximized through the heat shrinkage expression to maximize the interfacial separation between the initial component and the core component.

For reference, the interfacial peeling between the initial component and the core component occurs 50 to 60% in the short fiber manufacturing process, and the manufactured short fiber passes through the carding process of the nonwoven fabric process such as needle punching or high pressure liquids. Due to the physical impact, the interfacial separation between the supercomponent and the core components reaches 70% to 80%.

Hereinafter, the present invention will be described in detail.

In the present invention, polyamide fibers such as nylon means nylon 6, nylon 66 or copolymerized nylon having these as main components. In addition, the nylon in the present invention is a relative viscosity generally used in the manufacture of textiles for clothing and non-woven fabrics of about 2.3 to 3.2, and uses 0.15% to 0.50% of inorganic particles by weight in order to improve stretchability. .

The polypropylene component is an isotactic polypropylene, and the melt flow rate (hereinafter referred to as "MF") is suitably 8 g / 10 minutes to 20 g / 10 minutes according to ASTM D-1238 (L). The higher the MF value, the higher the initial elastic modulus of the polypropylene. Therefore, a MF value of 18 g / 10 minutes or less is mainly used.

Polypropylene is a soft polymer with an initial modulus equivalent to that of nylon, and it is necessary to select a composite weight ratio that suits the purpose of the composite spinning weight ratio between 30/70 and 70/30. In addition, increasing the weight ratio of polypropylene increases the light weight of the composite fiber, but the strength of the composite fiber may be lowered, so the weight ratio should be selected as a whole. In general, the reason why soft fibers and nonwoven fabrics made of nylon is soft is due to low initial modulus and high elongation compared to polyester. Thus, in order to obtain flexibility equivalent to nylon, a polyolefin polymer having an initial elastic modulus equal to nylon It is optimal. For example, Korean Patent Application No. 98-56757 has prepared a short fiber for nonwoven fabric having excellent processability and touch by using a polyolefin polymer with a deep sheath type composite spinning.

The spinning temperature shall be adjusted to the polymer line temperature and spinning temperature of the supercomponent and the core component in accordance with the relative viscosity and the MF value of the supercomponent and the core component. In general, the super ingredient nylon 6 is suitable for 255 ℃ ~ 270 ℃, the core component polypropylene is suitable for 270 ℃ ~ 285 ℃. However, when the viscosity of the initial component and the core component are different from each other, the composite cross-section formation of the initial component and the core component is uneven, and trimming is likely to occur during spinning. Therefore, it can be said that it is important to match the melt viscosity of the initial component and the core component.

The unstretched toe spun in the super and core components undergoes a stretching process to obtain the target fineness, strength, and elongation. Nylon and polypropylene with low glass transition temperature can be stretched even at low temperatures. In order to remove the uniform stretching of the supercomponent and the core component and the oligomer of nylon, hydrothermal stretching of 90 ° C to 120 ° C is more advantageous than cold stretching. For reference, since nylon generates a large amount of oligomers, it is preferable to remove oligomers as much as possible in the short fiber manufacturing process so that workability due to oligomer dropout in post processing is not deteriorated by using the property that the oligomer is easily eluted in hot water.

Since the nylon and polypropylene are not subjected to external physical impact until the stretching process, the interfacial separation between the core component and the supercomponent does not occur, and in the present invention, in the crimper when the machine is crimped to produce short fibers having excellent heat retention and flexibility, By adding a pressure higher than the general crimper pressure to form a hollow through physical interfacial peeling between the super / core components, it is possible to obtain effects such as weight reduction or increased heat retention due to the hollow.

In order to more stably separate the secondary component and the core component separated by physical pressure, the superconducting nylon and the core component use the heat shrinkage difference of the polypropylene. Heat treatment temperature of a heat treatment apparatus such as a heat setter is 100 ~ 140 ℃ under the pressure of the crimper is sufficiently heat treated so that shrinkage difference of the polymer occurs. The degree of interfacial peeling between the primary component and the core component up to the second should be 50% to 60% of the total interfacial peeling in consideration of the carding properties of the nonwoven fabric manufacturing process, needle punching, and spun lace workability. The heat treatment temperature is preferably 140 ° C. or lower in consideration of the melting point of the polypropylene and the deterioration of physical properties.

In the present invention, the artificial leather is made of a non-woven fabric through the needle punching or spun lace after carding short fibers of the core and vinegar components as described above, the non-woven fabric is generally polyvinyl alcohol (hereinafter referred to as PVA) Padding), impregnated with polyurethane resin to impart elasticity, and PVA is eluted. The reason for adsorbing PVA is that when polyurethane coating is directly coated on a nylon nonwoven fabric, the coating area becomes wider, and the fluidity between the polyurethane coating and the nylon nonwoven fabric decreases, resulting in a hard and artificial touch. Therefore, by eluting the PVA after adsorbing it is possible to increase the fluidity between the polyurethane coating and nylon nonwoven fabric to obtain a flexible touch. In addition, in the present invention, even if the polyurethane is coated on the supercomponent, the core component is interfacially peeled, so that the fluidity is high, thereby making artificial leather having flexibility and lightness superior to existing artificial leather.

In the present invention, the measurement of each property and physical properties was measured by the following method.

(1) relative viscosity

Using 98% sulfuric acid as a solvent, the concentration was measured at a concentration of 1.0 g / dl and a temperature of 25 ° C.

(2) strength

Short fibers were measured using ASTM VIBRO, using a VIBRO DYN type, at a sample length of 30 mm and a tensile rate of 10 mm / min.

(3) initial modulus

It was recognized from the slope of the elongation curve obtained when the elongation was measured, that is, the fiber strength when the elongation was 3%.

(4) density

It was measured by a toluene-4 carbon chloride-based density gradient tube at 25 ° C.

(5) Card passability

The composite spun short fibers separating the herbaceous and core components are released by the card at a speed of 30 m / min at an interval of 18 g / m ² . At that time, the degree to which the quantity of the card | curd wound around the card was large was evaluated, and it described as good or bad.

(6) warmth

Thermal insulation evaluation was evaluated by KS K 0560 by the insulation evaluation tester specified in KS K 0466.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.

Example 1

Example 1 is supplied to a conventional extruder-type compound spinning machine at a weight ratio of 50/50 at a weight ratio of 0.40 wt% of a particle content and a nylon having a relative viscosity of 2.7 and a polypropylene MF value of 17 g / 10 min. After injection from a spinneret having 1500 spin holes with a diameter of 0.3 mm at a spinning temperature of 260 ° C, cooling consolidation and oiling were carried out to obtain a concentric spherical composite spinning fiber wound at a speed of 1500 m / min. The obtained composite spun fiber was drawn at a draw ratio of 3.0 at a draw temperature of 110 ° C., then heat-treated with a 120 ° C. heat treatment roller, and a single fiber was prepared by applying a physical pressure of ^2.0 Kgf / cm ² during mechanical crimp formation. And drying temperature was performed at 130 degreeC. Finally, the obtained composite spun short fibers were obtained in the needle punched nonwoven fabric process.

Example 2

Example 2 is the same as Example 1 except that 4.0 Kgf / cm ² of physical pressure is imparted upon mechanical crimping.

Example 3

Example 3 is the same as that of Example 1 except that 6.0 Kgf / cm ^{2 is} applied to the mechanical crimp.

Comparative Example 1

In Comparative Example 1, nylon 6 having a relative viscosity of 2.7 was supplied to a universal extruder type single spinning machine and spun at a spinning temperature of 265 ° C. to prepare a conventional nylon short fiber manufacturing process.

Table 1 shows the results of Examples and Comparative Examples.

TABLE 1

* Initial modulus: Strength at 3% elongation

Examples 1, 2, and 3 of the present invention show that the thermal insulation is superior to the nylon short fibers of Comparative Example 1 through the interfacial peeling of the supercomponent and the wet component under almost the same short fiber properties and nonwoven density. Initial elastic modulus was almost similar to the Examples and Comparative Examples, the flexibility of the nonwoven fabric was good in both Examples compared to Comparative Example 1. In addition, it can be seen that by using polypropylene, the density of the nonwoven fabric was lower than that of Comparative Example 1, which also contributed to the light weight.

According to the method for manufacturing a composite fiber according to the present invention as described above, the polyamide component of the polyamide component such as nylon as a polypropylene core component, but the incompatibility and heat shrinkage difference between the primary component and the core component and mechanical crimp Interfacial peeling through the high crimper pressure can improve the insulation and flexibility of short fibers and nonwoven fabrics by forming hollows between the supercomponent and nonwoven components, and can provide a competitive price compared to nonwoven fabrics made of nylon only. Functional composite spun short fibers and nonwovens can be obtained.

Claims (7)

Stretching after complex spinning with polyamide as a primary component and polypropylene as a core component; Imparting a mechanical crimp in the range of ^2.0 Kgf / cm ² to 6.0 Kgf / cm ² of the clamp pressure; Heat-treating the single yarn given the mechanical crimp in a temperature range of 100 to 140 ° C; Method for producing a deep sheath-type composite spun short fibers, characterized in that to form a hollow between the super / 芯 component by including. The method according to claim 1, wherein the polyamide is nylon having a relative viscosity of 2.3 to 3.2. The method of claim 1, wherein the polypropylene has a MF value of 8 to 20 g / min. The method according to claim 1, wherein the weight ratio of the vinegar component is in the range of 30/70 to 70/30. The method according to claim 1, wherein the rate at which interfacial peeling of the super / core component is expressed is 50% to 60% of the total ratio. Compound spinning yarns characterized in that the short-fiber interfacial peeling on the nonwoven fabric is expressed by the carding, cross wrapper and needle punching process prepared by the method of any one of claims 1 to 5 Textile nonwoven fabric. The composite spun short fiber nonwoven fabric according to claim 6, wherein the composite spun short fiber nonwoven fabric is coated with PVA and impregnated with a polyurethane resin to impart elasticity, and PVA is eluted and removed.