A fiber-reinforced polyurethane fine screen and its forming method

Abstract

The invention relates to the technical field of screens, and specifically to a fiber-reinforced polyurethane fine screen and a molding method thereof, wherein a plurality of transverse partitions are evenly arranged along the longitudinal direction of the screen plate, the transverse partitions and the longitudinal partitions divide the screen plate into a plurality of rectangular screening zones of the same size, the screen holes are distributed in the rectangular screening zones in a rectangular array manner, the screen holes are rectangular, and the long sides of the screen holes are parallel to the long sides of the rectangular screening zones, the top surfaces of the transverse partitions and the longitudinal partitions are respectively provided with cutting ribs along the axial direction, the cutting ribs are wavy in top view, and the vertical sections of the cutting ribs are equilateral triangles, a carbon fiber mesh is inlaid in the screen plate, the screen plate is integrally cast by polyurethane, the screen holes and the cutting ribs are processed by engraving, the outer wall of the screen is polished, corona treated and then coated with water-based polyurethane resin, and the problems of weak tensile strength, low opening rate, low screening efficiency and short service life of the polyurethane screen are solved.

Description

Technical Field

[0001] The invention relates to the technical field of screen meshes, in particular to a fiber-reinforced polyurethane fine screen mesh and a molding method thereof. Background Art

[0002] There are three important technical indicators for screens used to select powders or filter liquids in the fields of pharmaceuticals, mining, metallurgy, petrochemicals, and water treatment: the first is the opening rate, which is the ratio of the total area of ​​the screen holes to the total area of ​​the screen; the second is the size of the screen holes, which is the size of the screen holes suitable for different screening levels; and the third is the service life. Among them, the larger the opening rate, the higher the screening efficiency; the shorter the service life, the more frequent the screen replacement, which affects production and increases costs.

[0003] Traditional mine fine screens generally use metal woven screens or injected nylon screens. Although the opening rate of metal woven screens is as high as 50-55%, due to poor wear resistance, poor corrosion resistance, and frequent replacement, the labor intensity is high and the cost is high; secondly, the metal screen has poor elasticity and a fixed mesh size, which can easily cause the mesh to be blocked during screening, affecting the screening efficiency, and the working noise is high. The injected nylon fine screen is made of thermoplastic nylon injection molding. Due to the limitations of thermoplastic polymer injection molding processing, a large-sized integral screen cannot be produced. When used, it can only be spliced ​​with multiple small-sized screens. Due to the shortcomings of splicing and large mesh separation strips, the mesh opening rate is low, generally less than 10%, and the screening efficiency is very low. For example, the domestic patent CN2571508Y discloses a nylon fine screen with a slit width of 0.12 to 0.5 mm, but the mesh size is only 405×200 mm, which needs to be spliced ​​when used, and there are many splicing seams. In order to overcome the above shortcomings of metal screens and injected nylon screens, people have successfully developed polyurethane screens. Polyurethane screens have large size specifications, good elasticity, wear resistance, light weight, long life, no need for splicing when in use, low labor intensity, and low working noise.

[0004] However, the widely used polyurethane screens still have problems such as weak tensile strength, low opening rate, low screening efficiency and short service life. Summary of the invention

[0005] The object of the present invention is to provide a fiber reinforced polyurethane fine screen and a molding method thereof, so as to solve the problems of weak tensile strength, low opening rate, low screening efficiency and short service life of the polyurethane screen in the prior art.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a fiber-reinforced polyurethane fine screen, comprising a screen plate, a plurality of screen holes evenly arranged on the screen plate, a plurality of longitudinal partitions evenly arranged in the transverse direction, and a plurality of transverse partitions evenly arranged in the longitudinal direction of the screen plate, the transverse partitions and the longitudinal partitions divide the screen plate into a plurality of rectangular screening partitions of the same size, the screen holes are distributed in the rectangular screening partitions in a rectangular array, the screen holes are rectangular, and the long sides of the screen holes are parallel to the long sides of the rectangular screening partitions, the top surfaces of the transverse partitions and the longitudinal partitions are respectively provided with cutting ribs along the axial direction, the cutting ribs are wavy in shape when viewed from above, and the vertical section of the cutting ribs is an equilateral triangle, the screen plate is inlaid with a carbon fiber mesh, the screen plate is integrally cast from polyurethane, and the screen holes and the cutting ribs are processed by engraving.

[0007] Preferably, the outer wall of the sieve plate is coated with water-based polyurethane resin.

[0008] Preferably, the hardness of the polyurethane material used for processing the screen is 82-92 Shore A.

[0009] Preferably, the length of the sieve plate is 2000-2500 mm, the width is 1200-1800 mm, and the thickness is 3-6 mm; the length of the sieve hole is 2-4 mm, the width is 0.2-0.5 mm, the thickness of the rectangular sieve area is 0.4-1.0 mm, and the net distance between the sieve holes is 0.2-0.5 mm.

[0010] A method for forming a fiber-reinforced polyurethane fine screen comprises the following steps:

[0011] S1. Weaving a carbon fiber mesh using carbon fiber ribs, and placing the woven carbon fiber mesh horizontally in a mold cavity;

[0012] S2, injecting polyurethane into the mold cavity where the carbon fiber mesh is laid, cooling the mold to 60°C after the polyurethane is cured, and then opening the mold to take out the polyurethane sheet;

[0013] S3, carving and shaping according to the shape and size of the sieve holes and the cut strips;

[0014] S4, grinding the engraved screen and then performing corona treatment;

[0015] S5, preparing waterborne polyurethane resin material;

[0016] First, 90 parts of polytetramethylene ether glycol and polycarbonate diol were mixed, 105 parts of isophorone diisocyanate, 12 parts of diaminosulfonate, and 220 parts of deionized water were selected by mass; 16 parts of 1,4-butanediol, 12 parts of 2,2-dimethylolpropionic acid, and 30 parts of butanone were added to a reactor for a sealed chemical reaction to obtain a preliminary reaction product;

[0017] Secondly, adding 10 parts by weight of ethylenediamine to the above-mentioned preliminary reaction product and continuing the heating and mixing reaction to obtain a secondary reactant;

[0018] Next, water is added to the secondary reaction product to mix and emulsify the mixture to obtain a final product;

[0019] Finally, the final product is kept warm and then cooled and discharged to obtain a waterborne polyurethane resin;

[0020] S6. Immerse the entire corona-treated screen into water-based polyurethane resin for coating treatment.

[0021] Preferably, in step S1, the diameter of the carbon fiber ribs of the carbon fiber mesh located at the outer frame position is 1 mm, the diameter of the carbon fiber ribs located at the transverse and longitudinal spacers is 0.3 mm, and the diameter of the carbon fiber ribs located between the sieve holes is 0.1 mm.

[0022] Preferably, in step S5, the temperature of the chemical reaction when the preliminary reactants are obtained is 80-85°C, the temperature of the chemical reaction when the secondary reaction products are obtained is 75-80°C, and the temperature of the emulsification when the final product is obtained is 70-75°C.

[0023] Preferably, in step S5, the duration of the chemical reaction when the preliminary reactants are obtained is 4 to 5 hours, the duration of the chemical reaction when the secondary reaction products are obtained is 1 to 1.5 hours, and the duration of emulsification when the final product is obtained is 1 to 1.5 hours.

[0024] Preferably, in step S6, the screen is immersed in the aqueous polyurethane resin for 3 to 5 hours, and the immersion temperature is 20 to 25°C.

[0025] Preferably, after the screen is coated in step S6, the temperature range for drying is 125-135°C.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The fine screen mesh involved in the present invention has a high opening rate, which greatly improves the screening efficiency.

[0028] 2. The fine screen of the present invention is provided with a carbon fiber mesh inside, thereby increasing the tensile strength of the entire screen, and is light in weight and flexible.

[0029] 3. The fine screen mesh involved in the present invention is provided with wavy cutting strips on the transverse partitions and the longitudinal partitions, thereby providing a multi-directional cutting effect and further improving the screening efficiency.

[0030] 4. The surface of the fine screen involved in the present invention is coated with water-based polyurethane resin, which increases the wear resistance, aging resistance and weather resistance of the screen, thereby greatly increasing the service life of the screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall structure of the present invention from a top view;

[0032] Figure 2 For the present invention Figure 1 Schematic diagram of the enlarged structure at point A in the middle.

[0033] In the figure: 1-screen plate; 2-transverse spacers; 3-longitudinal spacers; 4-screen holes; 5-carbon fiber mesh; 6-cutting strips. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] See also Figure 1-2 The present invention provides a technical solution, a fiber reinforced polyurethane fine screen, comprising a screen plate 1, a plurality of screen holes 4 are evenly arranged on the screen plate 1, a plurality of longitudinal partitions 3 are evenly arranged along the horizontal direction of the screen plate 1, a plurality of transverse partitions 2 are evenly arranged along the longitudinal direction of the screen plate 1, the transverse partitions 2 and the longitudinal partitions 3 divide the screen plate 1 into a plurality of rectangular screening partitions of the same size, the screen holes 4 are distributed in the rectangular screening partitions in a rectangular array, the screen holes 4 are rectangular, and the long sides of the screen holes 4 are parallel to the long sides of the rectangular screening partitions, the top surfaces of the transverse partitions 2 and the longitudinal partitions 3 are respectively provided with cutting strips 6 along the axial direction, the cutting strips 6 are wavy in top view, and the vertical section of the cutting strips 6 is an equilateral triangle, a carbon fiber net 5 is inlaid in the screen plate 1, the screen plate 1 is integrally cast by polyurethane, and the screen holes 4 and the cutting strips 6 are processed by engraving.

[0036] In this embodiment, the outer wall of the sieve plate 1 is coated with water-based polyurethane resin.

[0037] In this embodiment, the hardness of the polyurethane material used for processing the screen is 82-92 Shore A.

[0038] In this embodiment, the length of the sieve plate 1 is 2000-2500 mm, the width is 1200-1800 mm, and the thickness is 3-6 mm; the length of the sieve hole 4 is 2-4 mm, the width is 0.2-0.5 mm, and the thickness of the rectangular sieve area is 0.4-1.0 mm, and the net distance between the sieve holes 4 is 0.2-0.5 mm.

[0039] A method for forming a fiber-reinforced polyurethane fine screen comprises the following steps:

[0040] S1, using carbon fiber ribs to weave a carbon fiber mesh 5, and placing the woven carbon fiber mesh 5 horizontally in a mold cavity;

[0041] S2, injecting polyurethane into the mold cavity where the carbon fiber mesh 5 is laid, cooling the mold to 60° C. after the polyurethane is cured, and then opening the mold to take out the polyurethane sheet;

[0042] S3, carving and shaping according to the shape and size of the sieve hole 4 and the cut strips 6;

[0043] S4, grinding the engraved screen and then performing corona treatment;

[0044] S5, preparing waterborne polyurethane resin material;

[0045] First, 90 parts of polytetramethylene ether glycol and polycarbonate diol were mixed, 105 parts of isophorone diisocyanate, 12 parts of diaminosulfonate, and 220 parts of deionized water were selected by mass; 16 parts of 1,4-butanediol, 12 parts of 2,2-dimethylolpropionic acid, and 30 parts of butanone were added to a reactor for a sealed chemical reaction to obtain a preliminary reaction product;

[0046] Secondly, adding 10 parts by weight of ethylenediamine to the above-mentioned preliminary reaction product and continuing the heating and mixing reaction to obtain a secondary reactant;

[0047] Next, water is added to the secondary reaction product to mix and emulsify the mixture to obtain a final product;

[0048] Finally, the final product is kept warm and then cooled and discharged to obtain a waterborne polyurethane resin;

[0049] S6. Immerse the entire corona-treated screen into water-based polyurethane resin for coating treatment.

[0050] In this embodiment, in step S1, the diameter of the carbon fiber ribs located at the outer frame of the carbon fiber mesh 5 is 1 mm, the diameter of the carbon fiber ribs located at the transverse spacers 2 and the longitudinal spacers 3 is 0.3 mm, and the diameter of the carbon fiber ribs located between the sieve holes 4 is 0.1 mm.

[0051] In this embodiment, the temperature of the chemical reaction when the preliminary reactants are obtained in step S5 is 80-85°C, the temperature of the chemical reaction when the secondary reaction products are obtained is 75-80°C, and the temperature of the emulsification when the final product is obtained is 70-75°C.

[0052] In this embodiment, the duration of the chemical reaction when the preliminary reactants are obtained in step S5 is 4 to 5 hours, the duration of the chemical reaction when the secondary reaction products are obtained is 1 to 1.5 hours, and the duration of emulsification when the final product is obtained is 1 to 1.5 hours.

[0053] In this embodiment, in step S6, the screen is immersed in the aqueous polyurethane resin for 3 to 5 hours, and the immersion temperature is 20 to 25°C.

[0054] In this embodiment, after the screen is coated in step S6, the temperature range for drying is 125-135°C.

[0055] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0056] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for forming a fiber-reinforced polyurethane fine screen, comprising a screen plate (1), wherein a plurality of screen holes (4) are evenly arranged on the screen plate (1), characterized in that: The sieve plate (1) is evenly provided with a plurality of longitudinal spacers (3) in the transverse direction, and the sieve plate (1) is evenly provided with a plurality of transverse spacers (2) in the longitudinal direction, the transverse spacers (2) and the longitudinal spacers (3) divide the sieve plate (1) into a plurality of rectangular sieve sections of the same size, the sieve holes (4) are distributed in the rectangular sieve sections in a rectangular array, the sieve holes (4) are rectangular, and the long sides of the sieve holes (4) are parallel to the long sides of the rectangular sieve sections, the top surfaces of the transverse spacers (2) and the longitudinal spacers (3) are respectively provided with cutting strips (6) in the axial direction, the cutting strips (6) are wavy in top view, and the vertical section of the cutting strips (6) is an equilateral triangle, the sieve plate (1) is inlaid with a carbon fiber net (5), the sieve plate (1) is integrally cast from polyurethane, and the sieve holes (4) and the cutting strips (6) are processed by engraving; The outer wall of the sieve plate (1) is coated with water-based polyurethane resin, the hardness of the polyurethane material used for processing the sieve is 82-92 Shore A, the length of the sieve plate (1) is 2000-2500 mm, the width is 1200-1800 mm, and the thickness is 3-6 mm; the length of the sieve hole (4) is 2-4 mm, the width is 0.2-0.5 mm, and the thickness of the rectangular sieve area is 0.4-1.0 mm, and the net distance between the sieve holes (4) is 0.2-0.5 mm; The following steps are involved: S1, using carbon fiber ribs to weave a carbon fiber mesh (5), and placing the woven carbon fiber mesh (5) horizontally in a mold cavity; S2, injecting polyurethane into the mold cavity where the carbon fiber mesh (5) is laid, cooling the mold to 60° C. after the polyurethane is solidified, and then opening the mold to take out the polyurethane sheet; S3, carving and shaping according to the shape and size of the sieve hole (4) and the cut strips (6); S4, grinding the engraved screen and then performing corona treatment; S5, preparing waterborne polyurethane resin material; First, 90 parts of polytetramethylene ether glycol and polycarbonate diol were mixed, 105 parts of isophorone diisocyanate, 12 parts of diaminosulfonate, and 220 parts of deionized water were selected by mass; 16 parts of 1,4-butanediol, 12 parts of 2,2-dimethylolpropionic acid, and 30 parts of butanone were added to a reactor for a sealed chemical reaction to obtain a preliminary reaction product; Secondly, adding 10 parts by weight of ethylenediamine to the above-mentioned preliminary reaction product and continuing the heating and mixing reaction to obtain a secondary reactant; Next, water is added to the secondary reaction product to mix and emulsify the mixture to obtain a final product; Finally, the final product is kept warm and then cooled and discharged to obtain a waterborne polyurethane resin; S6, immersing the entire corona-treated screen into an aqueous polyurethane resin for coating; The screen is immersed in the waterborne polyurethane resin for 3 to 5 hours at a temperature of 20 to 25°C. After the screen is coated, the drying temperature range is 125 to 135°C.

2. The method for forming a fiber-reinforced polyurethane fine screen according to claim 1, characterized in that: In the step S1, the diameter of the carbon fiber ribs located at the outer frame of the carbon fiber mesh (5) is 1 mm, the diameter of the carbon fiber ribs located at the transverse spacers (2) and the longitudinal spacers (3) is 0.3 mm, and the diameter of the carbon fiber ribs located between the sieve holes (4) is 0.1 mm.

3. The method for forming a fiber-reinforced polyurethane fine screen according to claim 2, characterized in that: In step S5, the temperature of the chemical reaction when the preliminary reactants are obtained is 80-85°C, the temperature of the chemical reaction when the secondary reaction products are obtained is 75-80°C, and the temperature of the emulsification when the final products are obtained is 70-75°C.

4. The method for forming a fiber-reinforced polyurethane fine screen according to claim 3, characterized in that: In step S5, the duration of the chemical reaction when the primary reactants are obtained is 4 to 5 hours, the duration of the chemical reaction when the secondary reaction products are obtained is 1 to 1.5 hours, and the duration of the emulsification when the final products are obtained is 1 to 1.5 hours.

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