A processing method for high-strength wear-resistant screen plates

Abstract

This invention provides a processing method for high-strength wear-resistant screen plates. Belonging to the technical field of polyurethane screen plates, this invention utilizes a steel wire skeleton embedded in a mold. Polyurethane compound and thermoplastic polyurethane elastomer are mixed in an internal mixer and then molded in a compression molding machine. Simultaneously, carbon black is added for filling during the compression molding process. This allows for the production of high-strength, wear-resistant, and elastic polyurethane compound screen plates, similar to conventional rubber processing machinery. This type of screen plate offers advantages such as high operating temperature, leveraging the high open area of ​​the steel wire and the excellent cushioning and shock absorption properties of the polyurethane compound and thermoplastic polyurethane elastomer after mixing. Therefore, it provides significant vibration reduction and noise reduction, while also extending the service life of the stainless steel screen plate.

Description

Technical Field

[0001] This invention belongs to the field of polyurethane screen technology, specifically relating to a processing method for a high-strength wear-resistant screen. Background Technology

[0002] Transforming the metal screen surface of traditional screening machines into an elastic screen surface, such as using elastic materials like rubber or polyurethane, not only provides better wear resistance and corrosion resistance but also effectively prevents material from clogging the screen holes. Polyurethane screen plates have gained popularity in the coal mining industry, and many factories and mines have begun research and development of polyurethane screen plates. However, due to erosion, the strength and plasticity of polyurethane screen plates weaken, and irregular round holes appear in some areas, leading to material leakage. CN201610553313.9 describes a refurbishment process for waste cast polyurethane screen plates, but its practical application results are poor. CN201711475314.7 describes a polyurethane screen plate and its preparation method. Therefore, those skilled in the art urgently need to develop a processing method for high-strength, wear-resistant screen plates to overcome the deficiencies of existing technologies and meet current market demands and performance requirements. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the main objective of the present invention is to provide a processing method for a high-strength wear-resistant screen plate.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A processing method for a high-strength wear-resistant screen plate includes the following steps: First, weighing the raw materials according to the formula; Second, at room temperature, adjusting the roller gap of an 80-90℃ open mill to 1.5-2mm, adding polyurethane compound, passing it through the mill five times, cutting it, adjusting the roller gap to 1-1.5mm, cutting it again, and then putting it back into the open mill roller gap. After wrapping the rollers, adding the other raw materials except the crosslinking agent in sequence, and mixing for 5-10 minutes, then adding the crosslinking agent, mixing in a triangular shape for 3-5 minutes, and cutting the polyurethane compound off the rollers for later use; Third, mixing the polyurethane compound and dried thermoplastic polyurethane elastomer in a 90-100℃ internal mixer for 5-10 minutes to obtain a polyurethane mixture; Fourth, placing the polyurethane mixture into a mold in a molding machine, molding it, and opening the mold to obtain a high-strength wear-resistant screen plate.

[0006] Furthermore, the first step formulation comprises, by weight, 100 parts polyurethane compound, 0.4-0.5 parts stearic acid or zinc stearate, 0.8-1 parts polyethylene wax, 3-4 parts dibenzothiazole disulfide, 8-11 parts carbon black, 1.5-2 parts dimercaptobenzothiazole, 1-1.5 parts sulfur, and 0.8-1 parts triallyl isocyanate.

[0007] Furthermore, the shaped polyurethane elastomer is dried at 80-90°C for 4-6 hours until the moisture content is below 200 ppm.

[0008] Furthermore, the fourth step of the molding process involves preheating for 3-5 minutes, molding for 3-5 minutes at a temperature of 160-170℃ and a pressure of 10-15MPa, followed by cold pressing for 3-4 minutes at a temperature of 30-40℃.

[0009] Furthermore, the mixing ratio of the polyurethane compound and the dried thermoplastic polyurethane elastomer in the third step is 13~17:11~19.

[0010] The beneficial effects of this invention are:

[0011] This invention discloses a processing method for high-strength wear-resistant screen plates. A steel wire skeleton is embedded in a mold. Polyurethane compound and thermoplastic polyurethane elastomer are mixed in an internal mixer and then molded in a compression molding machine. Carbon black is added as a filler in the compression molding process. This allows for the production of high-strength, wear-resistant, and elastic polyurethane compound screen plates, similar to conventional rubber processing machinery. This type of screen plate offers advantages such as high operating temperature, utilizing the high open area of ​​the steel wire and the excellent cushioning and shock absorption properties of the polyurethane compound and thermoplastic polyurethane elastomer after mixing. Therefore, it provides significant vibration reduction and noise reduction, while also extending the service life of the stainless steel screen plate. Detailed Implementation

[0012] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto. Example 1

[0013] Raw materials: KSK-80L internal mixer; Taihu New Materials zinc stearate; thermoplastic polyurethane elastomer Elastollan 1190A, polyurethane compound Millathane 76; polyethylene wax AC316A; Zhejiang East Rubber Additives dibenzothiazole disulfide, Anbang Chemical JN850 triallyl isocyanate; Shangshun Chemical MBT(M) dimercaptobenzothiazole, Ruibang RS-80 sulfur, Jindi carbon black J440.

[0014] The processing method for high-strength wear-resistant screen plates includes the following steps: embedding the steel wire skeleton into the mold in the molding machine as an insert, and further includes the following steps: Step 1: Weigh the raw materials according to the formula, which is 100 parts by weight of polyurethane compound, 0.4 parts of stearic acid or zinc stearate, 0.8 parts of polyethylene wax, 3 parts of dibenzothiazole disulfide, 8 parts of carbon black, 1.5 parts of dimercaptobenzothiazole, 1 part of sulfur, and 0.8 parts of triallyl isocyanate; Step 2: At room temperature, adjust the roll gap of the 80℃ open mill to 1.5mm, add the polyurethane compound, pass it through five times, cut it, continue to adjust the roll gap to 1mm, cut it again and put it into the roll gap of the open mill. After wrapping the rolls, add the other raw materials except for the crosslinking agent in sequence, and start the open mill. After 5 minutes, add the crosslinking agent, form a triangular package and start mixing for 3 minutes. Cut the polyurethane compound into rolls for later use. Third step: Dry the thermoplastic polyurethane elastomer at 80℃ for 4 hours until the moisture content is below 200ppm. The mixing ratio of the polyurethane compound and the dried thermoplastic polyurethane elastomer is 13:11. Mix the polyurethane compound and the dried thermoplastic polyurethane elastomer in a 90℃ internal mixer for 5 minutes, with the stirring shaft speed (front / back) at 39 / 30 rpm, to obtain the polyurethane compound. Fourth step: Place the polyurethane compound into a mold in a molding press and mold it. Open the mold. The molding process is: preheat for 3 minutes, press at 160℃ and 10MPa for 3 minutes, and then cold press at 30℃ for 3 minutes to obtain a high-strength, wear-resistant screen. Example 2

[0015] Raw materials: KSK-80L internal mixer; Shafeng zinc stearate; Dongcheng Chemical 6185A thermoplastic polyurethane elastomer, Millathane E40 polyurethane compound, SN9088D polyethylene wax; Zibo Shihong Chemical dibenzothiazole disulfide, Anbang Chemical JN850 triallyl isocyanate; Pingxiang Fengye Rubber aided dimercaptobenzothiazole, Shengtao Chemical IS60 sulfur.

[0016] The processing method for high-strength wear-resistant screen plates, which involves embedding the steel wire skeleton into the mold in a molding machine as an insert, also includes the following steps: Step 1: Weigh the raw materials according to the formula, which is 100 parts by weight of polyurethane compound, 0.45 parts of zinc stearate, 0.9 parts of polyethylene wax, 3.5 parts of dibenzothiazole disulfide, 9 parts of N330 carbon black, 1.7 parts of dimercaptobenzothiazole, 1.2 parts of sulfur, and 0.9 parts of triallyl isocyanate. Step 2: At room temperature, adjust the roll gap of an 85℃ open mill to 1.6mm, add the polyurethane compound, pass it through five times, then cut it. Continue adjusting the roll gap to 1.3mm, cut the material, and put it back into the open mill roll gap. After wrapping the rolls, add the other raw materials except for the crosslinking agent in sequence, and open mill for 7 minutes. After 4 minutes, add the crosslinking agent, form a triangular bag and start mixing for 4 minutes. Cut the polyurethane compound into rolls for later use. Third, dry the thermoplastic polyurethane elastomer at 85℃ for 5 hours until the moisture content is below 200ppm. The mixing ratio of the polyurethane compound and the dried thermoplastic polyurethane elastomer is 15:16. Mix the polyurethane compound and the dried thermoplastic polyurethane elastomer in a 95℃ internal mixer for 8 minutes, with the stirring shaft speed (front / back) at 39 / 30 rpm, to obtain the polyurethane compound. Fourth, place the polyurethane compound into a mold in a molding press and mold it. The molding process is: preheat for 4 minutes, press at 165℃ and 12MPa for 4 minutes, and then cold press at 35℃ for 3.5 minutes to obtain a high-strength, wear-resistant screen. Example 3

[0017] Raw materials: KSK-80L internal mixer; stearic acid SA-1801, TPUTExin 990R, Millathane CM, polyethylene wax AC316A; Duba Chemical dibenzothiazole disulfide, Hangzhou Keli KB-O triallyl isocyanate; Pingxiang Fengye Rubber aided dimercaptobenzothiazole, Sirubtis IS 7020 sulfur.

[0018] The processing method for high-strength wear-resistant screen plates, which involves embedding the steel wire skeleton into the mold in a molding machine as an insert, includes the following steps: Step 1: Weigh the raw materials according to the formula, which is 100 parts by weight of polyurethane compound, 0.5 parts of stearic acid, 1 part of polyethylene wax, 4 parts of dibenzothiazole disulfide, 11 parts of N220 carbon black, 2 parts of dimercaptobenzothiazole, 1.5 parts of sulfur, and 1 part of triallyl isocyanate; Step 2: At room temperature, adjust the roll gap of a 90℃ open mill to 2mm, add the polyurethane compound, pass it through five times, cut it, continue to adjust the roll gap to 1.5mm, cut it again, and put it back into the roll gap of the open mill. After wrapping the rolls, add the other raw materials except for the crosslinking agent in sequence, and mill for 10 minutes. Add crosslinking agent, mix in triangular bags for 5 minutes, and cut the polyurethane compound into rolls for later use; third step, dry the thermoplastic polyurethane elastomer at 90℃ for 6 hours until the moisture content is below 200ppm. The mixing ratio of polyurethane compound and dried thermoplastic polyurethane elastomer is 17:19. Mix the polyurethane compound and dried thermoplastic polyurethane elastomer in a 100℃ internal mixer for 10 minutes with a stirring shaft speed (front / back) of 39 / 30 rpm to obtain polyurethane compound; fourth step, place the polyurethane compound into a mold in a molding press and mold it. The molding process is preheating for 5 minutes, molding at 170℃ and 15MPa for 5 minutes, and cold pressing at 40℃ for 4 minutes to obtain a high-strength wear-resistant screen.

[0019] The polyurethane sieve plates of Examples 1-3 were subjected to performance tests, and the test results are shown in Table 1.

[0020] Table 1 Performance test results of polyurethane screen plates in Examples 1-3

[0021]

[0022] Note: Refer to GB / T33091-2016 Polyurethane Screen Plate.

Claims

1. A processing method for a high-strength wear-resistant screen plate, comprising the step of embedding a steel wire skeleton into a mold in a molding machine as an insert, characterized in that, It also includes the following steps: Step 1: Weigh the raw materials according to the formula. Step 2: At room temperature, adjust the roller gap of the 80-90℃ open mill to 1.5-2mm, add the polyurethane compound, pass it through the mill five times, then cut it. Continue to adjust the roller gap to 1-1.5mm, cut it again, and put it back into the open mill roller gap. After wrapping the rollers, add the other raw materials except the crosslinking agent in sequence, and mill for 5-10 minutes. Then add the crosslinking agent, form a triangular wrap, and mill for 3-5 minutes. Cut the polyurethane compound off the rollers for later use. Step 3: Mix the polyurethane compound and the dried thermoplastic polyurethane elastomer in a 90-100℃ internal mixer for 5-10 minutes to obtain a polyurethane mixture. Step 4: Place the polyurethane mixture into a mold in a molding press, press it into shape, and open the mold to obtain a high-strength wear-resistant screen plate.

2. The processing method for a high-strength wear-resistant screen plate according to claim 1, characterized in that, The first step formulation consists of 100 parts by weight of polyurethane compound, 0.4-0.5 parts of stearic acid or zinc stearate, 0.8-1 parts of polyethylene wax, 3-4 parts of dibenzothiazole disulfide, 8-11 parts of carbon black, 1.5-2 parts of dimercaptobenzothiazole, 1-1.5 parts of sulfur, and 0.8-1 parts of triallyl isocyanate.

3. The processing method for a high-strength wear-resistant screen plate according to claim 1, characterized in that, The shaped polyurethane elastomer is dried at 80-90℃ for 4-6 hours until the moisture content is below 200ppm.

4. The processing method for a high-strength wear-resistant screen plate according to claim 1, characterized in that, The fourth step of the molding process involves preheating for 3-5 minutes, molding for 3-5 minutes at a temperature of 160-170℃ and a pressure of 10-15MPa, and then cold pressing for 3-4 minutes at a temperature of 30-40℃.

5. The processing method for a high-strength wear-resistant screen plate according to claim 1, characterized in that, The mixing ratio of the polyurethane compound and the dried thermoplastic polyurethane elastomer in the third step is 13~17:11~19.

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