Diaphragm piece manufacturing process and equipment, diaphragm piece and filter press

Abstract

The invention discloses a diaphragm piece manufacturing process and equipment, a diaphragm piece and a filter press, and belongs to the technical field of plastic state substance processing. The manufacturing process comprises the following steps: S1, respectively preheating a diaphragm raw material and a centrifugal roller; s2, a release agent is formed on the inner wall of the centrifugal roller, the centrifugal roller is driven to operate, and the release agent is evenly distributed on the inner wall of the centrifugal roller; s3, uniformly mixing the diaphragm raw material with a curing agent to form a mixture; s4, putting the mixture into the centrifugal roller, and driving the centrifugal roller to operate, so that the mixture is uniformly distributed on the inner wall of the centrifugal roller; s5, the centrifugal roller is cooled until the mixture is cured, and a cured material is formed; and S6, the cured product is dried and then cooled, and the diaphragm piece product is obtained. The diaphragm sheet for the filter press, which is low in cost, uniform in thickness, easy to control and high in product percent of pass, can be prepared.

Description

Technical Field

[0001] The invention belongs to the technical field of plastic material processing, and in particular relates to a diaphragm production process, equipment, a diaphragm and a filter press. Background Art

[0002] The filter press utilizes a special mechanical filtering device that applies a certain pressure to the object, causing the liquid to seep out to achieve solid-liquid separation. The filter press is widely used in the field of solid-liquid separation.

[0003] The filtering mechanism of the filter press is mainly composed of multiple alternating and parallel material molds and water molds. The adjacent material molds and water molds are compressed by the compression mechanism of the filter press. The material to be processed is injected into the material cavity between the material mold partition and the filter cloth. The slurry is initially filtered out of part of the water through the material cavity. Then, the filtered water is injected into the filter cavity between the water mold partition and the diaphragm. The water in the material cavity is filtered out through the gradual expansion of the filter cavity. Finally, the slurry forms a cake, among which the extrusion diaphragm of the filter cavity is an important acting medium. The diaphragm plays a key role in the ductility squeezing and sealing.

[0004] At present, the manufacturing process of diaphragms is an injection molding process using a press and a mold. For example, a method for preparing a polypropylene diaphragm is disclosed in a Chinese invention patent with application number 200810180827.X, in which a polypropylene material is placed in a mixing and drying barrel for drying, and after drying, is placed in a screw heating barrel of an injection molding machine to melt the polypropylene material, and then the polypropylene material is pushed into a mold cavity, and the mold is taken out after maintaining the pressure for 8 to 10 minutes.

[0005] In the above method, the mold heating and cooling demolding time is relatively long, which directly affects the production capacity and the comprehensive cost is also very high. If the product specifications are updated, the mold needs to be redesigned. The process is cumbersome and the mold investment cost is also high. The biggest pain point is that the thickness of the injection molded diaphragm is difficult to control, resulting in an extremely high scrap rate of the diaphragm. The diaphragm is also prone to air hole defects, which will also affect its service life. Summary of the invention

[0006] In order to solve the above technical problems, the present application further improves the manufacturing process of the diaphragm sheet, in order to obtain a diaphragm sheet product with lower cost and higher product qualification rate. One of the purposes of the present invention is to provide a manufacturing process and equipment for a diaphragm sheet, the second purpose is to provide a diaphragm sheet prepared by the process, and the third purpose is to provide a filter press using the diaphragm sheet.

[0007] The specific technical solution is described below: A process for manufacturing a diaphragm sheet includes the following steps: S1: preheating the diaphragm sheet raw material and the centrifugal drum respectively; S2: forming a release agent on the inner wall of the centrifugal drum, driving the centrifugal drum to operate, so that the release agent is evenly distributed on the inner wall of the centrifugal drum; S3: uniformly mixing the diaphragm sheet raw material and the curing agent to form a mixture; S4: placing the mixture into the centrifugal drum, driving the centrifugal drum to operate, so that the mixture is evenly distributed on the inner wall of the centrifugal drum; S5: cooling the centrifugal drum until the mixture solidifies to form a solidified material; S6: drying the solidified product, and then cooling it to obtain a diaphragm sheet product.

[0008] There is no necessary order between steps S2 and S3 in the above technical solution. S3 may be performed first and then S2; or both steps may be performed simultaneously.

[0009] Preferably, in step S1, the preheating temperature of the diaphragm sheet raw material and the centrifugal drum are consistent.

[0010] Further preferably, in step S1, the preheating temperature of the diaphragm sheet raw material and the centrifugal drum is 80±10°C.

[0011] Preferably, in step S2, the rotation speed of the centrifugal drum is 60-100 rpm.

[0012] Preferably, in step S3, the curing agent is dichlorodiphenylmethane.

[0013] Further preferably, in step S3, the mass ratio of the diaphragm sheet raw material to the curing agent is 100:(18-25).

[0014] Preferably, in step S4, the rotation speed of the centrifugal drum is 1000-1500 rpm.

[0015] Preferably, in step S5, the centrifugal drum is cooled to 40±5°C.

[0016] Further preferably, in step S5, as the temperature decreases, the rotation speed of the centrifugal drum is synchronously reduced until it stops.

[0017] Preferably, in step S6, the drying temperature is 100±10° C., and the drying time is 6 to 10 hours.

[0018] A centrifugal device, used in the preparation process described in any of the above technical solutions, the centrifugal device comprises a base, a bracket, the centrifugal drum and a driving device; The support is arranged on the base, and the support is at least used to support the centrifugal drum and a driving device, and the driving device drives the centrifugal drum to rotate.

[0019] A diaphragm sheet is prepared by the preparation process described in any of the above technical solutions.

[0020] A filter press uses a diaphragm sheet prepared by the preparation process described in any of the above technical solutions as an extrusion diaphragm sheet of a filter press chamber.

[0021] In summary, the technical solution of the present invention has the following main beneficial effects: Compared with the prior art, the technical solution of the present invention obtains a diaphragm product with controllable and consistent thickness through the principle of centrifugation. At the same time, the bubbles in the product raw materials are thrown out together under the action of centrifugal force, eliminating the appearance of scrapped products, thereby obtaining a diaphragm product with a high pass rate; In addition, the preparation process described in the present invention can improve production capacity and reduce the overall cost of diaphragm products.

[0022] Further or more detailed beneficial effects will be described in detail in conjunction with specific examples in the specific implementation manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 1 is a schematic diagram of the structure of the centrifuge described in the embodiment; Figure 2 is a schematic diagram of the side cross-sectional structure of the centrifuge described in the embodiment; Figure 3 This is an appearance diagram of the diaphragm sheet product prepared in Example 1 in a superimposed state; Figure 4 This is a surface appearance picture of the diaphragm sheet product prepared in Example 1; Figure 5 These are the surface appearance pictures of the diaphragm sheet products prepared in Comparative Example 1-left and Comparative Example 2-right.

[0024] Reference numerals: 1: base, 2: bracket, 3: centrifugal drum, 3.1: protective door, 3.2: dry-burning heating tube, 4: driving device, 4.1: variable frequency speed regulating motor, 4.2: pulley, 4.3: belt, 4.4: rotating shaft, 4.5: bearing. DETAILED DESCRIPTION

[0025] The present invention is further explained with reference to the following embodiments: The core technical problem faced by the technical solution of the embodiment of the present application comes from the inventor's accurate understanding of the prior art. Therefore, how to improve the qualification rate of diaphragm products and reduce the overall cost is a technical problem that the inventor needs to solve urgently.

[0026] It should be noted that the embodiments do not constitute a limitation on the protection scope of the claims of the present invention. According to the technical concepts provided / proven by the embodiments, all technical solutions that can be reasonably anticipated by technicians in the relevant technical field should be included in the protection scope of the claims of the present invention.

[0027] The embodiments are described in detail as follows: The present embodiment relates to a preparation process of a diaphragm sheet, a centrifuge used in the preparation, a prepared diaphragm sheet product, and a filter press using the diaphragm sheet.

[0028] in: The manufacturing process of the diaphragm includes the following steps: S1: preheat the diaphragm sheet material and the centrifugal drum at 80±10℃ for 2 hours respectively; S2: forming a release agent on the inner wall of the centrifugal drum, driving the centrifugal drum to rotate centrifugally at a speed of 60 to 100 rpm, so that the release agent is evenly distributed on the inner wall of the centrifugal drum; S3: uniformly mixing the diaphragm sheet raw material and dichlorodiphenylmethane to form a mixture, wherein the mass ratio of the diaphragm sheet raw material to the dichlorodiphenylmethane is 100:(18-25); S4: placing the mixture into a centrifugal drum, driving the centrifugal drum to rotate at a speed of 1000-1500 rpm, so that the mixture is evenly distributed on the inner wall of the centrifugal drum; S5: Cooling the centrifugal drum to 40±5°C, and simultaneously reducing the rotation speed of the centrifugal drum until it stops, and the mixture solidifies to form a solidified material; S6: Dry the solidified product in an oven at 100±10°C for 6-10 hours, and cool it after drying to obtain a diaphragm product.

[0029] Embodiment 1: The diaphragm sheet for filter press is prepared by the following steps: S1: preheat the polyurethane prepolymer raw material and the centrifugal drum with a length of 2100 mm to 80°C respectively, keep the temperature constant for 2 hours; S2: Maintaining the centrifugal drum at a constant temperature of 80°C, applying the PU release agent to the inner wall of the centrifugal drum, and driving the centrifugal drum to rotate at a speed of 80 rpm, so that the PU release agent is evenly distributed on the inner wall of the centrifugal drum to form a layer; S3: the preheated polyurethane prepolymer raw material and dichlorodiphenylmethane are mixed in a mass ratio of 100:21.8, and stirred to form a mixture; S4: pouring the above mixture into a preheated centrifugal drum, driving the centrifugal drum to centrifugally rotate at a speed of 1200 rpm for 30 minutes, so that the mixture is evenly attached to the inner wall of the centrifugal drum; S5: Cooling the centrifugal drum to 40° C. within two hours, and simultaneously reducing the rotation speed of the centrifugal drum until it stops, so that the mixture solidifies to form a solidified product. After the centrifuge stops, the cylindrical solidified product is taken out and cut along the three-division mark line to form three prefabricated diaphragm sheets with a length of 700 mm; S6: drying the prefabricated diaphragm sheet in an oven at 100° C. for 6 hours, and cooling after drying; S7: trimming and making the required installation holes to obtain the diaphragm product.

[0030] In this embodiment: Step S1 preheats the polyurethane prepolymer raw material to make the raw material cure better, and the preheating of the centrifugal drum is to prevent the polyurethane prepolymer raw material from suddenly cooling down after being added to the drum, which affects the curing performance of the diaphragm sheet. The preheating time of the two is to ensure sufficient preheating; The release agent in step S2 is used to facilitate the removal and removal of the cured diaphragm sheet, and the low speed rotation of 80 rpm is used to ensure uniform heating of the release agent; The high-speed rotation of 1200 rpm in step S4 is to form a thin coating with uniform thickness as quickly as possible and to get rid of bubbles inside the diaphragm sheet; In step S5, the cooling time is extended to two hours to prevent the sudden drop in temperature from causing uneven thickness of the product. The drying step in step S6 is to stabilize the internal structure of the material so that it has better mechanical properties.

[0031] Please refer to the attached Figure 1~2 The centrifugal device used in this embodiment includes a base 1, a bracket 2 arranged on the base 1, a centrifugal drum 3 arranged on the bracket 2, and a driving device 4; the driving device 4 includes a variable frequency speed regulating motor 4.1, and the variable frequency speed regulating motor 4.1 drives a rotating shaft 4.4 to rotate in a bearing 4.5 through a pulley 4.2 and a belt 4.3, thereby driving the centrifugal drum 3 to perform centrifugal rotation; A protective door 3.1 is provided at the opening of the centrifugal drum 3 to cover the opening, and a dry-burning heating tube 3.2 and a temperature control system for controlling the heating temperature of the inner wall of the centrifugal drum 3 are provided in the interlayer of the side wall of the centrifugal drum 3.

[0032] The cylindrical inner wall of the centrifugal drum 3 in the centrifugal device has a smooth surface and is made of steel. The steel is preferably low-alloy high-strength structural steel, and more preferably Q355.

[0033] Please refer to the attached Figure 3~4 The diaphragm product prepared in this embodiment consists of Figure 3It can be seen that the thickness of several layers of diaphragm products is relatively uniform. After field measurement with a vernier caliper, the thickness of the diaphragm can be controlled within the range of 2.5±0.1mm. Depend on Figure 4 Visible: The surface of the diaphragm product is smooth and translucent, with no obvious bubbles visible to the naked eye; A batch of diaphragm products was tested using a hardness tester, and its hardness was Shore A60±2 degrees; The batch of diaphragm products was tested using a tensile testing machine, and its tensile strength can reach 6.5 MPa and the elongation at break can reach 600%.

[0034] The qualified rate of the batch of 50 diaphragm sheets prepared in this embodiment can reach 100%.

[0035] The diaphragm prepared in this embodiment is used as an extrusion diaphragm of the upper filter chamber of the filter press.

[0036] Comparative Example 1: The preparation process of the diaphragm for filter press is different from that of Example 1 in that: in step S4, the centrifugal drum is driven to rotate at a speed of 500 rpm for 30 minutes so that the mixture is evenly attached to the inner wall of the centrifugal drum.

[0037] Comparative Example 2: The preparation process of the diaphragm for filter press is different from that of Example 1 in that: in step S4, the centrifugal drum is driven to rotate at a speed of 500 rpm for 60 minutes so that the mixture is evenly attached to the inner wall of the centrifugal drum.

[0038] The thickness of the diaphragm prepared in Comparative Example 1 is within the range of 2.5±0.6 mm. Figure 5 As can be seen from the left part of the picture, there are visible bubbles on the surface of the diaphragm; The thickness of the diaphragm prepared in Comparative Example 2 is within the range of 2.5±0.2 mm. Figure 5 As can be seen from the right part of the picture, there are still visible bubbles on the surface of the diaphragm, but they are smaller and less than those in comparative example 1; The diaphragm prepared in Comparative Example 1 has a hardness of 60±2 degrees Shore A, a tensile strength of 4.7 MPa, and an elongation at break of up to 460%; The diaphragm prepared in Comparative Example 2 has a hardness of 60±2 degrees Shore A, a tensile strength of 5.2 mpa, and an elongation at break of up to 550%; It can be seen that if a lower rotation speed is used in step S4, it will take a longer time to obtain a uniformity in the thickness of the diaphragm sheet that matches (still inferior to) that of Example 1, and the lower rotation speed in this step has limited effect on removing bubbles, so that the physical properties of the obtained diaphragm sheet product are lower than those of Example 1.

[0039] Comparative Example 3: The preparation process of the diaphragm sheet for filter press is different from that of Example 1 in that: in step S5, natural cooling is adopted, and the time for the temperature of the centrifugal drum to drop to 40° C. is 45 minutes.

[0040] The thickness of a batch of diaphragm sheets prepared in Comparative Example 3 is within the range of 2.5±0.3 mm, and the thickness uniformity of the diaphragm sheet products is lower than that of Example 1.

[0041] Comparative Example 4: The preparation process of the diaphragm sheet for filter press is different from that of Example 1 in that step S6 is eliminated.

[0042] The diaphragm prepared in Comparative Example 4 has a hardness of Shore A55±2, a tensile strength of 6.2 MPa, and an elongation at break of 590%. The diaphragm product is not further dried, and its physical properties are lower than those of Example 1.

[0043] Embodiment 2: The preparation process of the diaphragm for filter press is different from that of Example 1 only in that: in step S1, the preheating temperature of the centrifugal drum is 10°C lower than the preheating temperature of the polyurethane prepolymer raw material, the preheating temperature of the polyurethane prepolymer raw material is 80°C, and the preheating temperature of the centrifugal drum is 70°C.

[0044] The diaphragm product prepared in Example 2 was tested for hardness, tensile strength and elongation at break, and its physical properties were comparable to those of the diaphragm product prepared in Example 1; The thickness uniformity of a batch of 50 diaphragm sheets prepared in Example 2 was measured. The thickness of the diaphragm sheets could be controlled within the range of 2.5±0.07 mm. The thickness uniformity of the products was slightly improved compared with that in Example 1.

[0045] The inventors lowered the preheating temperature of the centrifugal drum to match the temperature of the polyurethane prepolymer raw material, based on the fact that the polyurethane prepolymer raw material will lose heat when it is moved and poured into the centrifugal drum, resulting in a slight drop in temperature. They originally expected that this would save energy and further reduce costs. The thickness uniformity of the product is still slightly improved beyond the original expectation of the inventor. The reason may be that the lower temperature reduces the surface energy of the inner wall of the centrifugal drum, and at the same time, driven by the temperature difference, the polyurethane prepolymer raw material is easier and faster to cover the inner wall of the centrifugal drum, which helps to improve the thickness uniformity of the product.

[0046] Embodiment 3: The preparation process of the diaphragm sheet for filter press is different from that of Example 1 only in that: In step S2, the rotation speed of the centrifugal drum is 60 rpm; In step S3, the polyurethane prepolymer raw material and dichlorodiphenylmethane are mixed at a mass ratio of 100:18; In step S4, the rotation speed of the centrifugal drum is 1000 rpm.

[0047] Embodiment 4: The preparation process of the diaphragm sheet for filter press is different from that of Example 1 only in that: In step S2, the rotation speed of the centrifugal drum is 100 rpm; In step S3, the polyurethane prepolymer raw material and dichlorodiphenylmethane are mixed at a mass ratio of 100:25; In step S4, the rotation speed of the centrifugal drum is 1500 rpm; In step S6, the drying time is 10 hours.

[0048] The diaphragm products prepared in Examples 3 and 4 were tested for hardness, tensile strength and elongation at break: The diaphragm prepared in Example 3 has a hardness of 59±2 degrees of Shore A, a tensile strength of 6.5 MPa, and an elongation at break of 610%; the diaphragm prepared in Example 4 has a hardness of 60±2 degrees of Shore A, a tensile strength of 6.5 MPa, and an elongation at break of 600%; The thickness uniformity of the diaphragm products prepared in Examples 3 and 4 was tested: In a batch of 50 diaphragm sheets prepared in Example 3 and Example 4, the thickness of the diaphragm sheets can be controlled within the range of 2.5±0.1 mm; It can be seen that the physical properties and uniformity of the thickness of the diaphragm sheet products prepared in Examples 3 and 4 are basically equivalent to those in Example 1.

[0049] In the description of this specification, the description with reference to the terms "embodiment", "basic embodiment", "preferred embodiment", "other embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0050] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0051] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A process for manufacturing a diaphragm, characterized in that: The steps include: S1: preheating the diaphragm sheet raw material and the centrifugal drum respectively; S2: forming a release agent on the inner wall of the centrifugal drum, driving the centrifugal drum to operate, so that the release agent is evenly distributed on the inner wall of the centrifugal drum; S3: uniformly mixing the diaphragm sheet raw material and the curing agent to form a mixture; S4: placing the mixture into the centrifugal drum, driving the centrifugal drum to operate, so that the mixture is evenly distributed on the inner wall of the centrifugal drum; S5: cooling the centrifugal drum until the mixture solidifies to form a solidified material; S6: drying the solidified product, and then cooling it to obtain a diaphragm sheet product.

2. The manufacturing process according to claim 1, characterized in that: In step S1, the preheating temperature of the diaphragm sheet raw material and the centrifugal drum is consistent.

3. The manufacturing process according to claim 2, characterized in that: In step S1, the preheating temperature of the diaphragm sheet raw material and the centrifugal drum is 80±10°C.

4. The manufacturing process according to claim 1, characterized in that: In step S2, the rotation speed of the centrifugal drum is 60-100 rpm.

5. The manufacturing process according to claim 1, characterized in that: In step S3, the curing agent is dichlorodiphenylmethane.

6. The manufacturing process according to claim 5, characterized in that: In step S3, the mass ratio of the diaphragm sheet raw material to the curing agent is 100:(18-25).

7. The manufacturing process according to claim 1, characterized in that: In step S4, the rotation speed of the centrifugal drum is 1000-1500 rpm.

8. The manufacturing process according to claim 1, characterized in that: In step S5, the centrifugal drum is cooled to 40±5°C.

9. The manufacturing process according to claim 8, characterized in that: In step S5, as the temperature decreases, the rotation speed of the centrifugal drum decreases synchronously until it stops.

10. The manufacturing process according to claim 1, characterized in that: In step S6, the drying temperature is 100±10°C and the drying time is 6 to 10 hours.

11. A centrifugal device, characterized in that: Used in the preparation process according to any one of claims 1 to 10, the centrifugal device comprises a base (1), a bracket (2), the centrifugal drum (3) and a driving device (4); The support (2) is arranged on the base (1), and the support (2) is used at least to support the centrifugal drum (3) and the driving device (4), wherein the driving device (4) drives the centrifugal drum (3) to rotate.

12. A diaphragm sheet, characterized in that: Prepared by the preparation process described in any one of claims 1 to 10.

13. A filter press, characterized in that: The diaphragm sheet prepared by the preparation process described in any one of claims 1 to 10 is used as an extruded diaphragm sheet of a filter press chamber.

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