CN105177732A - Method for filtering and deaerating high-viscosity spinning solution during melt direct spinning - Google Patents

Abstract

The invention relates to a method for filtering and defoaming the high-viscosity spinning solution in the melt direct spinning method, which comprises: filtering the high-viscosity spinning solution in the melt direct spinning method with a filter net of 200-300 mesh, and then passing it through 300-400 mesh in sequence Filter screen pressure filtration and 400-500 mesh filter screen pressure filtration. The method of the present invention fully removes all impurities in the spinning solution through multi-channel pressurized filtration from sparse to dense, so that the spinning solution is thoroughly filtered, and to a large extent avoids the formation of flame retardants and PET. Agglomerates cause spinneret blockage during spinning, and do not cause great loss of spinning solution during filtration. At the same time, the method of the invention has the advantages of economy and environmental protection, controllable reaction, short reaction time, simple equipment used, etc., and has great industrial application value.

Description

A method for filtering and defoaming high-viscosity spinning solution in melt direct spinning

technical field

The invention belongs to the field of filtering and defoaming of spinning liquid, in particular to a method for filtering and defoaming of high-viscosity spinning liquid in melt direct spinning.

Background technique

Polyester fiber occupies a huge share in the market. It has high strength, good elasticity, good heat resistance, light resistance, acid and alkali resistance, good processability and easy spinning. It can be purely spun, blended or interwoven, and its fabric is washable and durable. It is widely used in clothing, home textiles, decoration, industrial use and other fields.

With the development of polyester spinning from chip spinning to melt direct spinning, the online addition technology of melt direct spinning will become the main way to realize the modification and functionalization of polyester fibers. The equipment of melt direct spinning online adding technology is transformed from melt direct spinning equipment, which can produce a variety of differentiated and functional polyester products with high quality, good fastness, washing resistance and wear resistance. excellent. The key technology of melt direct spinning is accurate metering and uniform dispersion in online addition, and it is also a key technology that affects the properties of modified polyester fibers. Many experts and scholars actively research and explore this technology, and publish related patents and papers. Its main research directions are: spinneret (no mixer) based melt direct spinning on-line addition technology; melt direct spinning on-line addition technology based on dynamic mixer; melt direct spinning on-line addition technology based on static mixer; Melt direct spinning online adding technology based on combined mixer, etc.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for filtering and defoaming high-viscosity spinning liquid in the melt direct spinning method. Silk melt plays a continuous degassing effect; this method has the advantages of economy and environmental protection, controllable reaction, short reaction time, simple equipment used, etc., and has great industrial application value.

A method for filtering and defoaming the high-viscosity spinning solution in the melt direct spinning method of the present invention, comprising: filtering the high-viscosity spinning solution in the melt direct spinning method with a filter screen of 200-300 mesh, and then passing through 300-400 mesh in turn Pressurized filter with filter screen and pressurized filter with 400-500 mesh filter screen; wherein the pressure applied during the pressurized filter is 1-5 MPa.

The preparation of the high-viscosity spinning solution includes: in the twin-screw equipment, adding terephthalic acid PTA and ethylene glycol EG from the first section of the twin-screw feed port, direct esterification method copolymerization, in the second section of the material Flame retardant is added at the mouth, and high-viscosity spinning solution is obtained after blending.

The filtration and defoaming of the high-viscosity spinning solution is completed in the third section of the twin-screw.

The high-viscosity spinning solution is filtered and degassed, and then passed through the fourth stage of special degassing screw, then subjected to high-power stretching, heat-setting and winding to obtain high-strength flame-retardant polyester.

The molar ratio of PTA and EG is 1:1.1-1:1.2.

The flame retardant is 2-carboxyethylphenylphosphinic acid, polyphosphate amine or antimony pentoxide.

The added amount of the flame retardant is 2-8% of the total mass of PTA and EG.

The pressure filtration refers to applying pressure to the airtight equipment to make the spinning melt pass through the filter net, so as to achieve the effect of filtration.

The screw length-to-diameter ratio of the twin-screw equipment is 1:42-1:64, the screw speed is 150-200 rpm, and the screw temperature is 150-250°C.

The number of holes in the twin-screw spinneret is 500-3000, and the hole diameter is 0.1-0.4mm.

The first-stage drawing temperature of the high-power heating stretching is 60-100°C, the drawing ratio is 1-3 times, the second-stage drawing temperature is 60-100°C, the drawing ratio is 1-5 times, and the third-stage drawing temperature is 60-3 times. 100°C, the draft ratio is 1 to 5 times.

The heat-setting tension is controlled at 0.1-5kgf/cm, and the heat-setting temperature is 150-200°C.

Beneficial effect

(1) The method of the present invention fully removes all impurities and flame retardant aggregates in the spinning melt through multi-channel pressurized filtration from sparse to dense, so that the spinning melt is thoroughly filtered, from a large extent On the one hand, it avoids the blockage of the spinneret in the spinning process due to the flame retardant agglomerates formed when the flame retardant is blended with PET due to insufficient blending;

(2) method of the present invention combines with the polymerization of spinning melt, can not make spinning melt suffer very big loss in polymerization, filtration, defoaming process;

(3) The method of the present invention has the advantages of economy and environmental protection, controllable reaction, short reaction time, simple equipment used, etc., and has great industrial application value.

Detailed ways

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Example 1

Add terephthalic acid and ethylene glycol from the first section of the twin-screw, the molar ratio of PTA and EG is 1:1.1, copolymerize by direct esterification, and add flame retardant 2- Carboxyethylphenylphosphinic acid, the quality is 2% of the total mass of PTA and EG; after the flame retardant and PET are blended, filter with a 200-mesh filter in the third section of the screw, and then pass through a 300-mesh filter in turn Pressure filtration and 500-mesh filter screen pressure filtration, the pressure of pressure filtration is 2MPa; after passing through the fourth special degassing screw, high-strength stretching is carried out. The secondary drawing temperature is 60°C, the drawing ratio is 1 times, the third stage drawing temperature is 60°C, the drawing ratio is 1 times; the heat setting tension is controlled at 0.1kgf/cm, the heat setting temperature is 150°C, and the final heat setting winding Made into high-strength flame-retardant polyester, the breaking strength is 6.4cN/dtex, the breaking elongation is 11.5%, and the limiting oxygen index is 35%.

Example 2

Add terephthalic acid and ethylene glycol from the first section of the twin-screw, the molar ratio of PTA and EG is 1:1.2, copolymerize by direct esterification, and add flame retardant 2- Carboxyethylphenylphosphinic acid, the quality is 8% of the total mass of PTA and EG; after the flame retardant and PET are blended, filter with a 230-mesh filter in the third section of the screw, and then pass through a 325-mesh filter in turn Pressurized filtration and 450-mesh filter screen pressurized filtration, wherein the pressure of pressure filtration is 1MPa; after passing through the fourth special degassing screw, high-power stretching is carried out, the first-stage drawing temperature is 100°C, and the drawing ratio is 1 times The secondary drawing temperature is 100°C, the drawing ratio is 2 times, the third-stage drawing temperature is 100°C, and the drawing ratio is 3 times; the heat setting tension is controlled at 5kgf/cm, the heat setting temperature is 200°C, and finally the heat setting is wound into High-strength flame-retardant polyester with a breaking strength of 7.2cN/dtex, a breaking elongation of 15.1%, and a limiting oxygen index of 38.5%.

Example 3

Add terephthalic acid and ethylene glycol from the first stage of the twin-screw, the molar ratio of PTA and EG is 1:1.15, copolymerize by direct esterification, and add the flame retardant polyphosphoric acid at the second stage of the screw Amine, the quality is 6% of the total mass of PTA and EG; after the flame retardant and PET are blended, filter with a 270-mesh filter in the third section of the screw, and then pass through a 350-mesh filter for pressure filtration and 480-mesh filter Net pressure filtration, wherein the pressure of pressure filtration is 5MPa; and then high-stretching is carried out after passing through the fourth special degassing screw, the first-stage drawing temperature is 80°C, the drawing ratio is 1 times, and the second-stage drawing temperature is 90°C , the drawing ratio is 2 times, the third-stage drawing temperature is 100°C, and the drawing ratio is 3 times; the heat-setting tension is controlled at 3kgf/cm, the heat-setting temperature is 180°C, and finally heat-setting is wound into high-strength flame-retardant polyester, the breaking strength It is 8.1cN/dtex, the elongation at break is 13.5%, and the limiting oxygen index is 39.7%.

Example 4

Add terephthalic acid and ethylene glycol from the first stage of the twin-screw, the molar ratio of PTA and EG is 1:1.16, copolymerize by direct esterification, and add the flame retardant polyphosphoric acid at the second stage of the screw Amine, the quality is 4% of the total mass of PTA and EG; after the flame retardant and PET are blended, filter with a 250-mesh filter in the third section of the screw, and then pass through a 350-mesh filter for pressure filtration and 500-mesh filter Net pressurized filtration, wherein the pressure of pressurized filtration is 3MPa; after passing through the fourth special degassing screw, high-power stretching is carried out, the first-stage drawing temperature is 60°C, the drawing ratio is 1 times, and the second-stage drawing temperature is 70°C , the drawing ratio is 3 times, the third-stage drawing temperature is 90°C, and the drawing ratio is 5 times; the heat-setting tension is controlled at 2kgf/cm, the heat-setting temperature is 170°C, and finally heat-setting is wound into high-strength flame-retardant polyester, the breaking strength It is 8.1cN/dtex, the elongation at break is 13.5%, and the limiting oxygen index is 39.3%.

Example 5

Add terephthalic acid and ethylene glycol from the first stage of the twin-screw, the molar ratio of PTA and EG is 1:1.13, copolymerize by direct esterification, and add flame retardant pentoxide to the second stage of the screw Diantimony, the quality is 2% of the total mass of PTA and EG; after the flame retardant and PET are blended, filter with a 270-mesh filter in the third section of the screw, and then pass through a 325-mesh filter for pressure filtration and 400-mesh The filter is pressurized and filtered, and the pressure of the pressurized filter is 4MPa; after passing through the fourth special degassing screw, high-stretching is carried out. The first-stage drawing temperature is 80°C, the drawing ratio is 1 times, and the second-stage drawing temperature is 90 ℃, the drawing ratio is 2 times, the third-stage drawing temperature is 100℃, and the drawing ratio is 3 times; the heat-setting tension is controlled at 2.5kgf/cm, the heat-setting temperature is 190°C, and finally heat-setting is wound into high-strength flame-retardant polyester, The breaking strength was 7.3cN/dtex, the breaking elongation was 14.6%, and the limiting oxygen index was 35.9%.

Example 6

Add terephthalic acid and ethylene glycol from the first stage of the twin-screw, the molar ratio of PTA and EG is 1:1.12, copolymerize by direct esterification, and add flame retardant pentoxide to the second stage of the screw Diantimony, the quality is 7% of the total mass of PTA and EG; after the flame retardant and PET are blended, filter with a 230-mesh filter in the third section of the screw, and then pass through a 300-mesh filter for pressure filtration and 500-mesh The filter is pressurized and filtered, and the pressure of the pressurized filter is 3MPa; after passing through the fourth section of special degassing screw, high-stretching is carried out. The first-stage drawing temperature is 80°C, the drawing ratio is 2 times, and the second-stage drawing temperature is 90 ℃, the drawing ratio is 3 times, the third-stage drawing temperature is 100℃, and the drawing ratio is 4 times; the heat-setting tension is controlled at 4.5kgf/cm, the heat-setting temperature is 185°C, and finally heat-setting is wound into high-strength flame-retardant polyester, The breaking strength was 6.9cN/dtex, the breaking elongation was 13.9%, and the limiting oxygen index was 38.6%.

Claims (7)

1. the filtration defoaming method of a fused mass directly spinning method medium-high viscosity spinning solution, comprise: by fused mass directly spinning method medium-high viscosity spinning solution 200-300 object filter screen filtration, then successively through the screen pack pressure filtration of 300-400 object and the pressure filtration of 400-500 object screen pack; In the process of wherein pressure filtration, applied pressure is 1 ~ 5MPa.

2. the filtration defoaming method of a kind of fused mass directly spinning method medium-high viscosity spinning solution according to claim 1, it is characterized in that, the preparation of described high viscosity spinning solution comprises: in twin screw device, terephthalic acid (TPA) PTA and ethylene glycol EG is added from the first paragraph material mouth of twin-screw, direct esterification copolymerization, add fire retardant at second segment material mouth, after blended, obtain high viscosity spinning solution.

3. the filtration defoaming method of a kind of fused mass directly spinning method medium-high viscosity spinning solution according to claim 2, is characterized in that, the filtration deaeration of described high viscosity spinning solution completes the 3rd section of twin-screw.

4. the filtration defoaming method of a kind of fused mass directly spinning method medium-high viscosity spinning solution according to Claims 2 or 3, it is characterized in that, the screw slenderness ratio of described twin screw device is 1:42 ~ 1:64, and screw speed is 150 ~ 200rpm, and extruder temperature is 150-250 DEG C; Twin-screw spinnerets hole count is 500 ~ 3000, and aperture is 0.1 ~ 0.4mm.

5. the filtration defoaming method of a kind of fused mass directly spinning method medium-high viscosity spinning solution according to claim 2, it is characterized in that, described PTA and EG mol ratio is 1:1.1-1:1.2.

6. the filtration defoaming method of a kind of fused mass directly spinning method medium-high viscosity spinning solution according to claim 2, it is characterized in that, the consumption of described fire retardant is the 2-8% of PTA and EG gross mass.

7. the filtration defoaming method of a kind of fused mass directly spinning method medium-high viscosity spinning solution according to claim 2 or 6, it is characterized in that, described fire retardant is 2-carboxyethyl phenyl phosphinic acid, polyphosphoric acid amine or antimony pentoxide.