Production process of cold-resistant polyarylester canvas

Abstract

The invention discloses a production process of cold-resistant polyarylester canvas. The production process comprises the following steps: S1, using polyarylester precursor as a raw material; s2, performing thread twisting treatment on the polyarylester protofilaments by using a rope twisting machine; s3, performing secondary twisting treatment on the twisted yarns by using a secondary twisting machine; s4, weaving the secondarily twisted silk into canvas; s5, the woven canvas is subjected to gum dipping treatment, and a gum dipping formula comprises, by weight, 0.57 part of caustic soda flakes, 21 parts of resorcinol, 31 parts of formaldehyde, 462 parts of butadiene-vinylpyridine rubber latex, 25 parts of ammonia water, 430.43 parts of water and 30 parts of penetrating agents. According to the invention, the problems that the glue solution is only attached to the surface and the binding force is poor in the current polyarylate canvas production are effectively solved.

Description

Technical Field

[0001] This invention relates to a production process for cold-resistant polyarylate canvas, belonging to the field of polyarylate canvas production. Background Technology

[0002] In industrial applications, canvas is commonly used to manufacture conveyor belts, especially in scenarios requiring weather resistance and durability. With industrial development, the performance requirements for materials in extreme environments are increasing. For example, in cold regions, conveyor belts need to maintain flexibility and functionality. Canvas materials are typically made from fibers through processes such as twisting, weaving, and impregnation. Currently, aramid canvas is widely used due to its excellent flame retardancy and high-temperature resistance. However, in ultra-low temperature environments, such as below -30 degrees Celsius, aramid canvas hardens, causing the conveyor belt to lose its flexibility and become unusable. Polyarylate materials possess advantages such as high strength, high modulus, good flame retardancy, chemical resistance, low creep rate, excellent dielectric properties, and resistance to high and low temperatures. When applied to canvas production processes, the applicant found that existing adhesives only adhere to the LCP surface, resulting in poor bonding and low adhesion. During adhesion tests, the rubber detaches completely, with coverage essentially at zero. Summary of the Invention

[0003] Based on the above, the present invention provides a production process for cold-resistant polyaryl tarpaulin to solve the problems of poor adhesion and adhesive strength in the production of polyaryl tarpaulin, where the adhesive only adheres to the surface.

[0004] The technical solution of this invention is: a production process for cold-resistant polyarylate canvas, comprising:

[0005] S1. Use polyarylate (LCP) precursor fibers as raw materials;

[0006] S2. Twist the polyarylate (LCP) precursor yarn using a twisting machine;

[0007] S3. Use a retwisting machine to retwist the twisted yarn;

[0008] S4. The retwisted silk is woven into canvas;

[0009] S5. The woven canvas is impregnated with resin, wherein the impregnation formula, by weight, is: 0.57 parts caustic soda flakes, 21 parts resorcinol, 31 parts formaldehyde, 462 parts butadiene-pyridine latex, 25 parts ammonia, 430.43 parts water, and 30 parts penetrant.

[0010] Preferably, the impregnation formulation further includes 0.5 to 1 part of poly(N-isopropylacrylamide).

[0011] Preferably, the penetrant is an alkylphenol polyoxyethylene ether.

[0012] Preferably, the twisting process in step S2 uses a twisting machine with the following process parameters: twist of 35±5 T / m and spindle speed of 1500±100 rpm.

[0013] Preferably, the retwisting process in step S3 uses a retwisting machine with the following process parameters: required twist of 35±5 T / m, spindle speed of 1100±100rpm, and hooks of 6300*2+6300+6300.

[0014] Preferably, in step S4, the process of weaving the retwisted yarn into canvas requires a warp density of 40±2, a weft density of 32±2, a machine speed of 166±20R / min, and a weaving tension of 600N.

[0015] Preferably, in step S5, the impregnation process is set as follows:

[0016] Control the impregnation speed: 3~5m / min;

[0017] Temperature control parameters: H1 oven temperature is 80~100℃, H2 oven temperature is 80~100℃, H3 oven temperature is 80~100℃, H4 oven temperature is 80~100℃, and H5 oven temperature is 185~205℃.

[0018] Tension control parameters: Zone 1 tension is 1000 daN, stretching zone tension is 2300 daN, drying zone tension is 1000 daN, and setting zone tension is 2800 daN.

[0019] Control the extrusion pressure parameters: Extrusion pressure #1 is 1000 daN, extrusion pressure #2 is 1000 daN;

[0020] Control the vacuum suction parameters: Vacuum suction #1 is 4 mbar, vacuum suction #2 is 4 mbar;

[0021] Control the circulating air volume parameters: H1 oven circulating air volume is 70%, H2 oven circulating air volume is 65%, H3 oven circulating air volume is 50%, H4 oven circulating air volume is 50%, and H5 oven circulating air volume is 60%.

[0022] Preferably, when the ambient temperature is <10℃, the impregnation speed is adjusted to 2~3m / min; when the ambient temperature is between 10 and 20℃, the impregnation speed is adjusted to 3~4m / min; and when the ambient temperature is >20℃, the impregnation speed is adjusted to 4~5m / min.

[0023] The beneficial effects of this invention are as follows: By adding a penetrant to the impregnation formulation, this invention allows the adhesive to fully penetrate into the interior of the polyaryl ester fibers, solving the problem of traditional adhesives only adhering to the surface and having poor bonding strength. Tests show that after adding the penetrant, the adhesive strength can reach over 17.6 N / mm, and the peel coverage exceeds 86%, fully meeting the standards for canvas use. Furthermore, by adding poly(N-isopropylacrylamide) as a temperature-responsive polymer to the impregnation formulation and dynamically adjusting the impregnation speed according to the ambient temperature (reducing speed at low temperatures and increasing speed at high temperatures), the adhesive can achieve optimized penetration at different temperatures. This polymer expands at low temperatures to promote adhesive penetration and shrinks at high temperatures to prevent over-penetration, thereby further improving the coating uniformity and adhesive strength of the canvas. Detailed Implementation

[0024] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described in detail below. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0025] Example 1:

[0026] A production process for a cold-resistant polyarylate canvas includes:

[0027] S1. Use polyarylate (LCP) precursor fibers as raw materials;

[0028] S2. Use a twisting machine to twist the polyarylate (LCP) precursor yarn, requiring a twist of 35±5 T / m and a spindle speed of 1500±100 rpm.

[0029] S3. Use a retwisting machine to retwist the twisted yarn, requiring a twist of 35±5 T / m, a spindle speed of 1100±100rpm, and hooks of 6300*2+6300+6300.

[0030] S4. Weave the retwisted yarn into canvas with a warp density of 40±2, a weft density of 32±2, a machine speed of 166±20R / min, and a weaving tension of 600N.

[0031] S5. The woven canvas is impregnated with sizing agent. The sizing agent formula is shown in Table 1, and the impregnation process is as follows:

[0032] Control the impregnation speed: 4m / min;

[0033] Temperature control parameters: H1 oven temperature is 90℃, H2 oven temperature is 90℃, H3 oven temperature is 90℃, H4 oven temperature is 90℃, and H5 oven temperature is 200℃.

[0034] Tension control parameters: Zone 1 tension is 1000 daN, stretching zone tension is 2300 daN, drying zone tension is 1000 daN, and setting zone tension is 2800 daN.

[0035] Control the extrusion pressure parameters: Extrusion pressure #1 is 1000 daN, extrusion pressure #2 is 1000 daN;

[0036] Control the vacuum suction parameters: Vacuum suction #1 is 4 mbar, vacuum suction #2 is 4 mbar;

[0037] Control the circulating air volume parameters: H1 oven circulating air volume is 70%, H2 oven circulating air volume is 65%, H3 oven circulating air volume is 50%, H4 oven circulating air volume is 50%, and H5 oven circulating air volume is 60%.

[0038] Tension control, extrusion pressure control, vacuum adhesive suction control, and circulating air volume control are carried out simultaneously to ensure uniform treatment of the canvas during the adhesive impregnation process.

[0039]

[0040] Example 2:

[0041] The difference from Example 1 is that the impregnation formula also includes 0.8 kg of poly-N-isopropylacrylamide. In addition, the impregnation speed is set as follows: when the ambient temperature is <10°C, the impregnation speed is adjusted to 2.5 m / min (low speed increases the penetration time); when the ambient temperature is between 10 and 20°C, the impregnation speed is adjusted to 3.5 m / min; when the ambient temperature is >20°C, the impregnation speed is adjusted to 4.5 m / min (high speed prevents over-impregnation). This speed adjustment is achieved by installing a temperature sensor near the impregnation tank and connecting it to a PLC controller, which outputs a signal to adjust the speed of the impregnation roller motor.

[0042] It should be noted that when adding poly(N-isopropylacrylamide) to the impregnation formulation, the poly(N-isopropylacrylamide) powder should first be dispersed in water and stirred for 30 minutes to form a gel before being added to the adhesive solution.

[0043] The rest is the same as in Example 1.

[0044] Compare with Example 1:

[0045] The difference from Example 1 is that no penetrant was added; otherwise, they are the same as in Example 1.

[0046] The polyarylate canvases prepared in Examples 1 and 2 and Comparative Example 1 were subjected to adhesion tests, and their coverage was statistically analyzed. The adhesion test conditions were in accordance with GB / T 34225-2017.

[0047]

[0048] The test results are shown in Table 2. The canvas standard requires an adhesive strength of no less than 15 N / mm and a peel coverage of no less than 80%. Before adding the penetrant, the adhesive only adhered to the LCP surface, resulting in poor bonding, low adhesion, and overall detachment of the rubber, with virtually zero coverage. The product was far from meeting the standards. After adding the penetrant, the adhesive penetration was excellent, the bond was tight, the adhesive strength was ≥15 N / mm, and the coverage was ≥80%. Furthermore, adding the temperature-responsive polymer poly-N-isopropylacrylamide and setting the impregnation speed to respond to the ambient temperature further improved the adhesive strength and peel coverage. This is because dynamic impregnation speed control ensures optimized impregnation at different temperatures, improving the uniformity of the canvas coating; while the added temperature-responsive polymer expands at low temperatures to promote penetration and shrinks at high temperatures to prevent over-penetration.

[0049] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A production process for cold-resistant polyarylate canvas, characterized in that, include: S1. Use polyarylate precursor fibers as raw materials; S2. Twist the polyarylate precursor yarn using a twisting machine; S3. Use a retwisting machine to retwist the twisted yarn; S4. The retwisted silk is woven into canvas; S5. The woven canvas is impregnated with resin, wherein the impregnation formula, by weight, is: 0.57 parts caustic soda flakes, 21 parts resorcinol, 31 parts formaldehyde, 462 parts butadiene-pyridine latex, 25 parts ammonia, 430.43 parts water, and 30 parts penetrant.

2. The production process of the cold-resistant polyarylate canvas according to claim 1, characterized in that, The impregnation formulation also includes 0.5 to 1 part of poly(N-isopropylacrylamide).

3. The production process of the cold-resistant polyarylate canvas according to claim 1, characterized in that, The penetrant is alkylphenol polyoxyethylene ether.

4. The production process of the cold-resistant polyarylate canvas according to claim 1, characterized in that, The twisting process in step S2 uses a twisting machine with the following process parameters: twist of 35±5 T / m and spindle speed of 1500±100 rpm.

5. The production process of the cold-resistant polyarylate canvas according to claim 1, characterized in that, The retwisting process in step S3 uses a retwisting machine with the following process parameters: required twist of 35±5 T / m, spindle speed of 1100±100rpm, and hooks of 6300*2+6300+6300.

6. The production process of the cold-resistant polyarylate canvas according to claim 1, characterized in that, In step S4, the process of weaving the retwisted yarn into canvas requires the following: warp density 40±2, weft density 32±2, machine speed 166±20R / min, and weaving tension 600N.

7. The production process of the cold-resistant polyarylate canvas according to claim 1, characterized in that, In step S5, the impregnation process is set as follows: Control the impregnation speed: 3~5m / min; Temperature control parameters: H1 oven temperature is 80~100℃, H2 oven temperature is 80~100℃, H3 oven temperature is 80~100℃, H4 oven temperature is 80~100℃, and H5 oven temperature is 185~205℃. Tension control parameters: Zone 1 tension is 1000 daN, stretching zone tension is 2300 daN, drying zone tension is 1000 daN, and setting zone tension is 2800 daN. Control the extrusion pressure parameters: Extrusion pressure #1 is 1000 daN, extrusion pressure #2 is 1000 daN; Control the vacuum suction parameters: Vacuum suction #1 is 4 mbar, vacuum suction #2 is 4 mbar; Control the circulating air volume parameters: H1 oven circulating air volume is 70%, H2 oven circulating air volume is 65%, H3 oven circulating air volume is 50%, H4 oven circulating air volume is 50%, and H5 oven circulating air volume is 60%.

8. The production process of the cold-resistant polyarylate canvas according to claim 7, characterized in that, When the ambient temperature is <10℃, the impregnation speed should be adjusted to 2~3m / min; when the ambient temperature is between 10 and 20℃, the impregnation speed should be adjusted to 3~4m / min; when the ambient temperature is >20℃, the impregnation speed should be adjusted to 4~5m / min.

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