KR910001800B1 - Manufacturing method of polypropilen filament yarn - Google Patents

Abstract

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Description

Manufacturing method of fine fine polypropylene filament yarn

1 is a longitudinal cross-sectional view of a spinning pack consisting of a non-ferrous metal particulate stack and a spinning nozzle.

2 is a process schematic diagram of the present invention.

* Description of the main parts of the drawings

1: spinning pack 2: non-ferrous metal particulate laminate

3: spinneret 4: cotton pocket

5: 30-120 micron fine particle layer 6: 120-260 micron fine particle layer

7: 260-480 micron fine particle layer 8: 480-2500 micron fine particle layer

10: spinning yarn 11: cooling tube

12 cooling air 13 spinning fluid injector

14: high-speed winding, odor 9: 840-2500 micron fine particle layer

The present invention relates to a method for producing a fine polypropylene filament yarn (hereinafter referred to as PPMF yarn) by a high-speed melt spinning method.

The present invention will be described in more detail by melting, extruding, stretching after high-speed winding using an isotactic polypropylene having a narrow molecular weight distribution and having an elastic three-symmetric spiral structure. It is characterized in that the foreign matter in the melt is removed from the stack of non-metallic fine particles, and then melt spun and fast wound using a spinning nozzle having spinning holes under specific conditions.

Sesumadosa prepared by the present invention has high orientation and high crystallinity, thereby exhibiting excellent physical properties even at a low draw ratio and improving manufacturing processability.

Conventional polypropylene manufacturing method is as follows.

U.S. Patent Nos. 4,225,299, 4,193,961 and 4,347,206 reduce the dieswell of the molten polymer at a low temperature of 204 ° C to install an isothermal chamber directly under the spinneret to produce a uniform fineness PPMF yarn. This was caused by severe fluctuations and fusion caused by the unsolidification of the spinning yarn at the time of high-speed winding, which deteriorated the properties and fairness. According to US Pat. No. 3,621,088, the spinning yarn was quenched in water, but this was possible in low speed winding, but it was difficult to work due to friction between the spinning yarn and water in high speed winding of 2,000m / min or more.

European Patent Publication No. 0,028,844 stretched two to four times the high-speed extrusion wound yarn to produce high-tension, low-elasticity, and high elasticity PPMF yarn. Elongation is given, but it is difficult to give high elasticity and there is a problem of high trimming rate in the stretching process. In addition, when the draw ratio of the high-speed wound PPMF yarn was 1.8 or more, fibril was generated in the PPMP yarn and the drawing process was degraded.

Japanese Patent Laid-Open Publication No. 51, l12921 is a method for producing PPMF yarn having a fineness of 500 to 1,500 denier, and a polypropylene having a melt index (MI) of 5 and a viscosity (η) of 1.66 at a pore diameter (D) of 1.5 mm. Winding at 52m / min using a spinning nozzle with 3.5mm and high equipment (L / D) for pore diameter of 10 to 20, and cooling solidification method of spinning yarn sprays water into air at 5 ℃ -20 ℃ It is a method of cooling and solidifying the spinning yarn using the supersaturated air.

When the above method is applied to the manufacture of the high-speed winding PPMF of the present invention, D and L / D of the spinning nozzle are inadequate, resulting in a decrease in fairness, and the trimming rate increases during spinning and stretching as it solidifies with a supersaturated cooling wind. The process control is difficult because many fibrils are generated. The present invention solves the problems of the prior art as described above, and improves the physical properties and processability of PPMF as described in detail below.

The present invention relates to a method for producing PPMF yarn by high-speed melt spinning, in particular, a fine-grained PPMF yarn of 100 denier or less, and a method for imparting excellent physical properties and radioactivity. The melt spinning method of PPMF, which cools and pulls out the spinning yarn obtained by melt extruding polypropylene, has been conventionally carried out, but has been limited in terms of the manufacturing process due to the unique properties of polypropylene.

For example, low extrudability, low speed radiation, high trimming rate, Taesumdo, low strength, low orientation, and high elongation.

An object of the present invention is to solve the difficulties in the manufacturing process of the depth PPMF company and to improve the coarse physical properties. In particular, it is a manufacturing method of fine-grained PPMF yarn by high-speed extrusion winding by melt spinning.

Polypropylene used in the present invention is melt-spinable, such as nylon and polyester, and the molecules must be oriented by stretching. The polymer used does not have dipole bonds like hydrogen or polyester between molecules, so molecular weight of 200,000 or more, polymer purity of 96% or more, isotacticity 95% The above-mentioned polypropylene is a polypropylene having a three-symmetric spiral structure for imparting elasticity. The molecular weight distribution (hereinafter referred to as MWD) is folded between 3 and 9, and the melt index is between 16 and 80 for high melt extrusion and winding. Should be polypropylene

Polypropylene with high melt viscosity and narrow MWD can be obtained by the following method. In general polypropylene, free radicals are generated by using a high temperature of 310 ° C. or higher, or radiation such as gamma (γ) or beta (β), and prodegradent, and these radicals are produced by hydrogen from the polypropylene backbone. Eliminates Since the backbone is cleaved at the point at which hydrogen is eliminated, the long molecule is cleaved preferentially. As a result, the molecular weight distribution becomes narrower and the melt index rises.

The polypropylene mentioned above is extrusion melted in an extruder to form the exit thread. Foreign matter in the melt is removed from the nonferrous metallic particulate stack having a size between 30 and 2,500 microns. Since polypropylene has high viscoelasticity, the removal of foreign matter in the melt with a conventional screen filter of 30 to 350 mesh results in high degree of fineness and melt leakage due to excessive pressure and pressure unevenness in the spin pack, resulting in poor processability. In particular, it is severe when the diameter of the spinning nozzle is small or when the viscosity of the resin used is large.

In order to solve such a problem, nonferrous metal particles having a size of 30 to 2,500 μ are stacked in a spinning pack in a proportion of 30 to 2,500 μ instead of a mesh screen filter to reduce the pressure and homogenize the melt in the spinning pack, and prevent melt leakage. .

And foreign matter in the melt, close to 30μ in size, can be removed without melt leakage. When the melt is filtered with such fine particles, even if the replacement cycle of the spin pack is 30 days or more, the physical properties of the yarn can be improved without causing a decrease in physical properties and processability. Since the nonferrous metallic microparticles are irregular granular, the porosity is very high and chemically very stable with respect to the molten polypropylene, and does not form a gel.

The non-ferrous metallic particulate laminate is 13% nickel (Ni) or less, 16% or less chromium (Cr), 2% or less molybdenum (Mo), 1% or less silicon (Si), 0.04% or less carbon, stainless steel 67.76 It consists of more than%.

The structure of the fine particle laminate implemented in the present invention is shown in FIG.

Multiple rooms with a pore diameter (D) of 0,2-0.6 mm and a plant ratio (L / D) of 3 to 8 for pore diameter to form a spinning yarn with a polypropylene melt from which foreign matter has been removed by the particulate stack. Spinning nozzles with slots should be used.

If the spinneret D is 0.2 mm or less, the spinning draft is too small and the diewell phenomenon due to the viscosity of the melt is severe and spinning is impossible.

In addition, when the pore diameter (D) is 0.6 mm or more, even if the spinning yarns can be formed, discharge bands are generated between the spinnerets during high-speed winding, thereby forming the spinning yarns. Therefore, fine-grained spinning yarns of less than 100 denier must have a pore size ranging from 0 2mw to 0.6mm. More suitable is to have an attack between 0.3mm and 0.5mm.

The factory (L) of the spinning nozzle is determined in consideration of the pore diameter (D), but must be 3 to 8 times the pore diameter.

Due to the relatively high melt viscosity of polypropylene, the plant ratio (L / D) to the pore diameter must be relatively large.

In the case of yarn spinning of 100 denier or less, which uses a 3 to 8 spinneret with a plant diameter (L / D) for the pore diameter, the radial draft is relatively large. Even in the draw ratio of the ratio, high strength and low elongation of PPMF yarn can be obtained. However, when the L / D exceeds 8, the pressure of the melt in the spin pack is increased, the melt leakage is severe and the spin draft is low, the degree of molecular alignment of the yarn is low. Therefore, even if the high magnification is drawn in the draw ratio in the drawing process, the necking is mixed, the physical properties are lowered, the drawing processability is also lowered.

The radial draft is calculated using the following equation.

[Equation 1]

Example 1

Polypropylene used has a melt index of 25 and 34 and a molecular weight distribution (MIVD) of 5.3 and 6.2.

Spinning nozzles with 20 spinnerets, a diameter (D) of 0.3 mm, and a plant ratio (L / D) of 5 were used. It melt-extruded at the melting part temperature of a screw of 270 degreeC, and the spin nozzle temperature of 285 degreeC, and it filtered by nonferrous metal microparticles | fine-particles.

The spinning yarn was solidified with a room temperature cooling wind at a speed of 0.2 m / sec, and the spinning yarn wound at a speed of 3,500 m / min at 2,000 m / min was drawn at a draw ratio of 1.6 and 1.72 times.

As a comparative example of this embodiment, the melt index is 10, 32, 46 isotacticity is less than 95%, the polymer purity is less than 96%.

Polypropylene having a molecular weight distribution of 11 was used, and other conditions were performed under the same conditions as in the present example.

The results of Examples and Comparative Examples are shown in Table 1.

In the comparative example, the temperature of the screw melter was changed from 230 ° C to 280 ° C, the spin nozzle temperature from 215 ° C to 285 ° C, and the air flow rate from 0.1 to 0.5m / sec. .

TABLE 1

w)를 수평균분자량(

n)으로 나눈값.* Note: 1) MWD is the weight average molecular weight (

w) is the number average molecular weight (

divided by n).

2) Ml is the melt index and measured based on ASTM 1238L.

Example 2

Non-ferrous metallic particulate stacks were used to remove debris in the polypropylene melt and to maintain a uniform pressure of the melt. The fine particle stack directly above the spinning nozzle is as follows.

[next]

The nonferrous metallic fine particle stack and the above-mentioned diameter (D) of 0.5mm, factory ratio (LyD) for the pore diameter of 4, using a spinneret of 20 spinning air, screw melting part temperature of 260 ℃, spinning nozzle temperature of 280 ℃ Was carried out.

The used polypropylene had a melt index of 30, a molecular weight distribution of 6, isotacticity 97%, polymer purity of 98%, and other conditions as in Example 3. As a comparative example, instead of nonferrous metallic particles, one composite screen of 10 to 45 mesh, one composite screen of 60 to 150 mesh, and one composite screen of 150 to 330 mesh are used as in Example 3, respectively.

When one more 150-330 mesh composite screen was used, the spin pack cycle was very short due to excessive pressure in the spin pack.

The results of the above-described Examples and Comparative Examples are shown in Table 2.

TABLE 2

Example 3

Using spinneret with 10 spinnerets, 0.3mm in pore diameter (D), and 7 plant ratios (L / D) for pore diameter, screw melt temperature is 265 ℃, spinning nozzle temperature is 280 ℃ and cooling wind speed is 0.4 m / sec and the winding speed were 3,200 m / min. The physical properties of polypropylene were filtered with a nonferrous metallic particulate laminate having a melt index of 36, isotacticity of 96%, polymer purity of 97%, and molecular weight distribution of 6.2. The draw ratio was 1.66. Spinning nozzles with a nominal diameter (D) of 0.4 mm and a factory cost (L / D) of 2 are used, and a radial nozzle with a nominal diameter (D) of 1.0 mm and a factory ratio (L / D) of 6 is used. The comparative example was tested on the same conditions as Example 3 except having used. In this comparative example, the screw melting part temperature is 230 ° C. to 230 ° C., the spinneret temperature is 220 ° C. to 290 ° C., and the wind speed is changed from 0.1 m / sec to 0.5 m / sec, and the winding speed is 2,000 to 3, 300 m / min. However, radiation and fusion occurred in certain drafts.

The result of Example 3 and its comparative example is shown in Table 3.

TABLE 3

Claims (2)

Using a polypropylene having a trisymmetric spiral structure having a molecular weight distribution of 3 to 9, a melt index of 16 to 80, an isotacticity of 95% or more, and a polymer purity of 96% or more, and the molten polypropylene is used as a particle size. Removes foreign matter by passing through a stack of nonferrous metallic particles having a thickness of 30-2,500 μ, and then a spinneret having a pore diameter (D) of 0.2-0.6 mm and a plant ratio (L / D) of 3 to 8 for the pore diameter (D). Method for producing a fine-grained polypropylene filament yarn characterized in that the spinning through the spinning nozzle having. The method of claim 1, wherein the nonferrous metallic laminate is a component of the polypropylene filament yarn, characterized in that the following components are laminated in the weight ratio. [bottom]

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