Microcellular foaming material for bag type dust removal and preparation method thereof

Abstract

The invention provides a microcellular foaming material for bag type dust removal and a preparation method thereof. The preparation method comprises the following steps: (1) weighing 60-80 parts by weight of linear polypropylene, 5-15 parts by weight of talcum powder and 1-3 parts by weight of a hydrophobic modifier, uniformly mixing, and carrying out melt extrusion granulation on a twin-screw extruder to obtain modified polypropylene granules; (2) adding the modified polypropylene granules into an organic solution containing a foaming agent and an auxiliary agent, and uniformly stirring; and (3) feeding the stirred material into a nitrogen-assisted injection molding machine for injection molding to obtain the microcellular foaming material for bag type dust removal. The hydrophobic modifier is selected to modify the linear polypropylene, the surface hydrophobicity of the microcellular foaming material is improved, the adhesion of dust is reduced, the ash removal difficulty is reduced, in addition, the talcum powder is added to be combined with a nitrogen-assisted injection molding process, surface foam marks of the microcellular foaming material can be effectively eliminated, the adhesion of the dust is further reduced, and the service life of the microcellular foaming material is prolonged. And the ash removal difficulty is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, in particular to a microporous foaming material for bag-type dust removal and a preparation method thereof. Background Art

[0002] In recent years, the frequent occurrence of haze weather has seriously affected people's production, life and health. With the enhancement of people's environmental awareness and the improvement of pollutant emission standards, it is urgent to prevent and control air pollution. Bag dust collectors are widely used in the treatment of flue gas dust due to their advantages such as stable dust removal performance, high filtration efficiency and wide application range. However, the current bag dust collectors still have the following problems:

[0003] 1) During the operation of the dust collector filter bag, due to factors such as dust scouring and pulse back-blowing compressed air deviating from the center of the filter bag, the filter bag mouth and bottom will be worn, especially the mouth wear, mostly within 40cm below the mouth, and the breakage is mostly from the inside to the outside;

[0004] 2) After the dust collector filter bag captures the dust, due to the adhesion of the dust, the dust on the surface of the filter bag is difficult to remove, affecting the air permeability and filtering effect of the filter bag;

[0005] 3) In a high temperature environment, dust easily adheres to the surface of the bag filter of the bag filter. After the dust clumps, the air permeability of the bag is reduced, thereby reducing the filtering effect of the bag.

[0006] Polypropylene has a wide range of uses due to its abundant raw material sources, low price, and easy processing and molding. At the same time, polypropylene has low density, excellent mechanical properties, and relatively excellent impact resistance, heat resistance, and chemical stability. Therefore, polypropylene is often used as the base material of foaming materials. However, after the current polypropylene microporous foaming material is prepared, its surface is often rough, which further amplifies the wear, cleaning, and bonding problems of dust collector filter bags. Summary of the invention

[0007] 1. Technical issues to be resolved

[0008] In view of the deficiencies in the prior art, the present invention provides a microporous foam material for bag-type dust removal and a preparation method thereof. A hydrophobic modifier is added to linear polypropylene to make the foamed material hydrophobic, thereby preventing dust adhesion. The heterogeneous nucleation effect of talcum powder combined with the pressure holding process in the nitrogen-assisted injection molding process can improve the foaming behavior of linear polypropylene, eliminate surface bubble marks of the microporous foam material, improve the surface quality of the microporous foam material, improve the problem of dust cleaning difficulty, and solve the problems raised in the above-mentioned background technology.

[0009] (II) Technical solution

[0010] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0011] According to a first aspect of the present invention, there is provided a method for preparing a microporous foam material for bag dust removal, comprising the following steps:

[0012] (1) weighing 60 to 80 parts of linear polypropylene, 5 to 15 parts of talc and 1 to 3 parts of a hydrophobic modifier by weight, mixing them evenly, and melt-extruding and granulating them on a twin-screw extruder to obtain modified polypropylene pellets;

[0013] (2) adding the modified polypropylene pellets into an organic solution containing a foaming agent and an auxiliary agent and stirring the mixture uniformly;

[0014] (3) The stirred material is fed into a nitrogen-assisted injection molding machine for injection molding to obtain the microporous foam material for bag-type dust removal.

[0015] Preferably, in step (1), the hydrophobic modifier is selected from at least one of dodecyldimethoxysilane, dodecylmethyldichlorosilane, dodecyltrichlorosilane, hexadecyltrimethoxysilane, hexadecyldimethylallylammonium chloride, octadecyltrichlorosilane and octadecyltrimethoxysilane;

[0016] The fineness of the talcum powder is 200-500 meshes.

[0017] Preferably, in step (1), the temperature of the melt extrusion is 150-170°C.

[0018] Preferably, in step (2), in the organic solution containing a foaming agent and an auxiliary agent, the foaming agent is selected from at least one of sodium lauryl sulfate, lauryl phosphate, alcohol polyoxyethylene ether sodium sulfate, and lauryl phosphate;

[0019] The organic solvent is selected from acetone and / or anhydrous ethanol;

[0020] The auxiliary agent is selected from antioxidants, crosslinking agents, antistatic agents, flame retardants and lubricants.

[0021] Specifically, the antioxidant is selected from phosphites or hindered phenols; preferably, the antioxidant is selected from antioxidant 168 or antioxidant 1010.

[0022] The cross-linking agent is selected from at least one of melamine, polyethyleneimine, chitosan, a silane coupling agent, and N,N-methylenebisacrylamide.

[0023] The antistatic agent is selected from at least one of monoglyceride, boric acid ester, liquid ethoxylated amine or solid ethoxylated amine.

[0024] The flame retardant is selected from at least one of aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate or brominated flame retardants.

[0025] The lubricant is selected from at least one of oleic acid amide, stearic acid amide or distearyl amide.

[0026] Preferably, in step (2), in the organic solvent containing the foaming agent and the auxiliary agent, the concentration of the foaming agent is 1 to 5%, and the concentration of the auxiliary agent is 0.1 to 5%.

[0027] Preferably, in step (2), the volume ratio of the mass of the modified polypropylene pellets to the organic solvent containing the foaming agent and the auxiliary agent is 1 g: 1 to 3 mL.

[0028] Preferably, in step (3), the injection molding temperature is 150-200° C., and the injection molding pressure is 15-30 MPa.

[0029] Preferably, in step (3), the holding pressure of the injection molding is 10 to 100 MPa, and the holding time is 10 to 20 s.

[0030] According to a second aspect of the present invention, there is provided a microporous foam material for bag-type dust removal obtained according to the above-mentioned preparation method, wherein the microporous foam material has an antenna angle with water of 150 to 170°.

[0031] Preferably, the cell size of the microporous foam material is 5 to 60 μm, and the cell density is greater than 10 9 / m 3 .

[0032] (III) Beneficial effects

[0033] The present invention provides a microporous foam material for bag dust removal and a preparation method thereof. It has the following beneficial effects:

[0034] (1) The present invention provides a method for preparing a microporous foam material for bag dust removal, wherein a hydrophobic modifier is selected to modify linear polypropylene to improve the surface hydrophobicity of the microporous foam material, reduce the adhesion of dust, and reduce the difficulty of cleaning. In addition, by adding talcum powder and combining it with a nitrogen-assisted injection molding process, the surface bubble marks of the microporous foam material can be effectively eliminated, further reducing the adhesion of dust and reducing the difficulty of cleaning.

[0035] (2) This scheme provides a microporous foam material for bag dust removal, with a three-dimensional mesh smooth film layer attached to the surface, and a pore size of 5 to 60 μm, which can effectively improve the filtration accuracy and mechanical properties, reduce dynamic filtration pressure loss, reduce dust deposition, reduce the difficulty of cleaning, and improve filtration efficiency. DETAILED DESCRIPTION

[0036] In order to better illustrate the content of the present invention, a detailed description is given below in conjunction with specific embodiments.

[0037] Example 1

[0038] A method for preparing a microporous foam material for bag dust removal comprises the following steps:

[0039] Step 1, weighing 70 kg of linear polypropylene, 10 kg of talc with a particle size of 400 mesh and 2 kg of hexadecylaminodimethylallyl ammonium chloride, mixing them evenly, and performing melt extrusion granulation at 150° C. in a twin-screw extruder to obtain modified polypropylene pellets;

[0040] Step 2, adding 82 kg of modified polypropylene pellets prepared in step 1 into 164 L of acetone solution containing a foaming agent and an auxiliary agent, and mixing and stirring uniformly, wherein the foaming agent is dodecyl phosphate, and the auxiliary agent includes an oxidant, a cross-linking agent, an antistatic agent, a flame retardant and a lubricant, wherein the oxidant is antioxidant 168, the cross-linking agent is polyethyleneimine, the antistatic agent is borate, the flame retardant is aluminum hydroxide, and the lubricant is oleamide, and the mass ratio of the antioxidant, the cross-linking agent, the antistatic agent, the flame retardant and the lubricant is 1:1:1:1:1, and the concentration of the foaming agent in the acetone solution containing the foaming agent and the auxiliary agent is 3%, and the concentration of the auxiliary agent is 1%;

[0041] Step 3: Send the stirred material into a nitrogen-assisted injection molding machine for injection molding to obtain a microporous foam material for bag dust removal, wherein the injection molding temperature is 160° C., the injection molding pressure is 20 MPa, the injection molding holding pressure is 50 MPa, and the holding time is 10 s.

[0042] Example 2

[0043] A method for preparing a microporous foam material for bag dust removal comprises the following steps:

[0044] Step 1, weighing 72 kg of linear polypropylene, 8 kg of talc with a particle size of 400 mesh and 2 kg of hexadecylaminodimethylallyl ammonium chloride, mixing them evenly, and performing melt extrusion granulation at 150° C. in a twin-screw extruder to obtain modified polypropylene pellets;

[0045] Step 2, adding 82 kg of modified polypropylene pellets prepared in step 1 into 164 L of acetone solution containing a foaming agent and an auxiliary agent, and mixing and stirring uniformly, wherein the foaming agent is dodecyl phosphate, and the auxiliary agent includes an oxidant, a cross-linking agent, an antistatic agent, a flame retardant and a lubricant, wherein the oxidant is antioxidant 168, the cross-linking agent is polyethyleneimine, the antistatic agent is borate, the flame retardant is aluminum hydroxide, and the lubricant is oleamide, and the mass ratio of the antioxidant, the cross-linking agent, the antistatic agent, the flame retardant and the lubricant is 1:1:1:1:1, and the concentration of the foaming agent in the acetone solution containing the foaming agent and the auxiliary agent is 3%, and the concentration of the auxiliary agent is 1%;

[0046] Step 3: Send the stirred material into a nitrogen-assisted injection molding machine for injection molding to obtain a microporous foam material for bag dust removal, wherein the injection molding temperature is 160° C., the injection molding pressure is 20 MPa, the injection molding holding pressure is 50 MPa, and the holding time is 10 s.

[0047] Example 3

[0048] A method for preparing a microporous foam material for bag dust removal comprises the following steps:

[0049] Step 1, weighing 70 kg of linear polypropylene, 5 kg of talc with a particle size of 400 mesh and 2 kg of hexadecylaminodimethylallyl ammonium chloride, mixing them evenly, and performing melt extrusion granulation at 150° C. in a twin-screw extruder to obtain modified polypropylene pellets;

[0050] Step 2, adding 77 kg of modified polypropylene pellets prepared in step 1 to 154 L of acetone solution containing a foaming agent and an auxiliary agent, and mixing and stirring uniformly, wherein the foaming agent is dodecyl phosphate, and the auxiliary agent includes an oxidant, a cross-linking agent, an antistatic agent, a flame retardant and a lubricant, wherein the oxidant is antioxidant 168, the cross-linking agent is polyethyleneimine, the antistatic agent is borate, the flame retardant is aluminum hydroxide, and the lubricant is oleamide, and the mass ratio of the antioxidant, the cross-linking agent, the antistatic agent, the flame retardant and the lubricant is 1:1:1:1:1, and the concentration of the foaming agent in the acetone solution containing the foaming agent and the auxiliary agent is 3%, and the concentration of the auxiliary agent is 1%;

[0051] Step 3: Send the stirred material into a nitrogen-assisted injection molding machine for injection molding to obtain a microporous foam material for bag dust removal, wherein the injection molding temperature is 160° C., the injection molding pressure is 20 MPa, the injection molding holding pressure is 50 MPa, and the holding time is 10 s.

[0052] Example 4

[0053] A method for preparing a microporous foam material for bag dust removal comprises the following steps:

[0054] Step 1, weighing 60 kg of linear polypropylene, 5 kg of talc with a particle size of 400 mesh and 1 kg of hexadecylaminodimethylallyl ammonium chloride, mixing them evenly, and performing melt extrusion granulation at 150° C. in a twin-screw extruder to obtain modified polypropylene pellets;

[0055] Step 2, adding 66 kg of modified polypropylene pellets prepared in step 1 into 99 L of acetone solution containing a foaming agent and an auxiliary agent, and mixing and stirring uniformly, wherein the foaming agent is dodecyl phosphate, and the auxiliary agent includes an oxidant, a cross-linking agent, an antistatic agent, a flame retardant and a lubricant, wherein the oxidant is antioxidant 168, the cross-linking agent is polyethyleneimine, the antistatic agent is borate, the flame retardant is aluminum hydroxide, and the lubricant is oleamide, the mass ratio of the antioxidant, the cross-linking agent, the antistatic agent, the flame retardant and the lubricant is 1:1:1:1:1, and the concentration of the foaming agent in the acetone solution containing the foaming agent and the auxiliary agent is 3%, and the concentration of the auxiliary agent is 1%;

[0056] Step 3: Send the stirred material into a nitrogen-assisted injection molding machine for injection molding to obtain a microporous foam material for bag dust removal, wherein the injection molding temperature is 160° C., the injection molding pressure is 20 MPa, the injection molding holding pressure is 50 MPa, and the holding time is 10 s.

[0057] Example 5

[0058] A method for preparing a microporous foam material for bag dust removal comprises the following steps:

[0059] Step 1, weighing 75 kg of linear polypropylene, 15 kg of talc powder with a particle size of 400 mesh and 2 kg of hexadecylaminodimethylallyl ammonium chloride, mixing them evenly, and performing melt extrusion granulation at 150° C. in a twin-screw extruder to obtain modified polypropylene pellets;

[0060] Step 2, adding 92 kg of modified polypropylene pellets prepared in step 1 to 138 L of acetone solution containing a foaming agent and an auxiliary agent, and mixing and stirring evenly, wherein the foaming agent is dodecyl phosphate, and the auxiliary agent includes an oxidant, a cross-linking agent, an antistatic agent, a flame retardant and a lubricant, wherein the oxidant is antioxidant 168, the cross-linking agent is polyethyleneimine, the antistatic agent is borate, the flame retardant is aluminum hydroxide, and the lubricant is oleamide, and the mass ratio of the antioxidant, the cross-linking agent, the antistatic agent, the flame retardant and the lubricant is 1:1:1:1:1, and the concentration of the foaming agent in the acetone solution containing the foaming agent and the auxiliary agent is 3%, and the concentration of the auxiliary agent is 1%;

[0061] Step 3: Send the stirred material into a nitrogen-assisted injection molding machine for injection molding to obtain a microporous foam material for bag dust removal, wherein the injection molding temperature is 160° C., the injection molding pressure is 20 MPa, the injection molding holding pressure is 50 MPa, and the holding time is 10 s.

[0062] Example 6

[0063] A method for preparing a microporous foam material for bag dust removal comprises the following steps:

[0064] Step 1, weighing 70 kg of linear polypropylene, 10 kg of talc with a particle size of 400 mesh and 2 kg of hexadecylaminodimethylallyl ammonium chloride, mixing them evenly, and performing melt extrusion granulation at 150° C. in a twin-screw extruder to obtain modified polypropylene pellets;

[0065] Step 2, adding 82 kg of modified polypropylene pellets prepared in step 1 into 98.4 L of acetone solution containing a foaming agent and an auxiliary agent, and mixing and stirring uniformly, wherein the foaming agent is sodium lauryl sulfate, and the auxiliary agent includes an oxidant, a cross-linking agent, an antistatic agent, a flame retardant and a lubricant, wherein the oxidant is antioxidant 1010, the cross-linking agent is chitosan, the antistatic agent is liquid ethoxyamine, the flame retardant is ammonium polyphosphate, and the lubricant is oleamide, and the mass ratio of the antioxidant, the cross-linking agent, the antistatic agent, the flame retardant and the lubricant is 1:1:1:1:1, and the concentration of the foaming agent in the acetone solution containing the foaming agent and the auxiliary agent is 5%, and the concentration of the auxiliary agent is 1%;

[0066] Step 3: Send the stirred material into a nitrogen-assisted injection molding machine for injection molding to obtain a microporous foam material for bag dust removal, wherein the injection molding temperature is 160° C., the injection molding pressure is 20 MPa, the injection molding holding pressure is 50 MPa, and the holding time is 10 s.

[0067] Comparative Example 1

[0068] A method for preparing a microporous foam material for bag dust removal comprises the following steps:

[0069] Step 1, weighing 70 kg of linear polypropylene and 2 kg of hexadecandimethylallyl ammonium chloride, mixing them evenly, and performing melt extrusion granulation at 150° C. in a twin-screw extruder to obtain modified polypropylene pellets;

[0070] Step 2, adding 72 kg of modified polypropylene pellets prepared in step 1 to 154 L of acetone solution containing a foaming agent and an auxiliary agent, and mixing and stirring uniformly, wherein the foaming agent is dodecyl phosphate, and the auxiliary agent includes an oxidant, a cross-linking agent, an antistatic agent, a flame retardant and a lubricant, wherein the oxidant is antioxidant 168, the cross-linking agent is polyethyleneimine, the antistatic agent is borate, the flame retardant is aluminum hydroxide, and the lubricant is oleamide, and the mass ratio of the antioxidant, the cross-linking agent, the antistatic agent, the flame retardant and the lubricant is 1:1:1:1:1, and the concentration of the foaming agent in the acetone solution containing the foaming agent and the auxiliary agent is 3%, and the concentration of the auxiliary agent is 1%;

[0071] Step 3: Send the stirred material into a nitrogen-assisted injection molding machine for injection molding to obtain a microporous foam material for bag dust removal, wherein the injection molding temperature is 160° C., the injection molding pressure is 20 MPa, the injection molding holding pressure is 50 MPa, and the holding time is 10 s.

[0072] Comparative Example 2

[0073] A method for preparing a microporous foam material for bag dust removal comprises the following steps:

[0074] Step 1, weighing 70 kg of linear polypropylene, 10 kg of talc with a particle size of 400 mesh and 2 kg of hexadecylaminodimethylallyl ammonium chloride, mixing them evenly, and performing melt extrusion granulation at 150° C. in a twin-screw extruder to obtain modified polypropylene pellets;

[0075] Step 2, adding 82 kg of modified polypropylene pellets prepared in step 1 into 164 L of acetone solution containing a foaming agent and an auxiliary agent, and mixing and stirring uniformly, wherein the foaming agent is dodecyl phosphate, and the auxiliary agent includes an oxidant, a cross-linking agent, an antistatic agent, a flame retardant and a lubricant, wherein the oxidant is antioxidant 168, the cross-linking agent is polyethyleneimine, the antistatic agent is borate, the flame retardant is aluminum hydroxide, and the lubricant is oleamide, and the mass ratio of the antioxidant, the cross-linking agent, the antistatic agent, the flame retardant and the lubricant is 1:1:1:1:1, and the concentration of the foaming agent in the acetone solution containing the foaming agent and the auxiliary agent is 3%, and the concentration of the auxiliary agent is 1%;

[0076] Step 3: sending the stirred material into a nitrogen-assisted injection molding machine for injection molding to obtain a microporous foam material for bag dust removal, wherein the injection molding temperature is 160° C. and the injection molding pressure is 20 MPa.

[0077] Comparative Example 3

[0078] A method for preparing a microporous foam material for bag dust removal comprises the following steps:

[0079] Step 1, weighing 70 kg of linear polypropylene and 10 kg of talc powder with a particle size of 400 mesh, mixing them evenly, and performing melt extrusion granulation at 150° C. in a twin-screw extruder to obtain modified polypropylene pellets;

[0080] Step 2, adding 80 kg of modified polypropylene pellets prepared in step 1 into 160 L of acetone solution containing a foaming agent and an auxiliary agent, and mixing and stirring evenly, wherein the foaming agent is dodecyl phosphate, and the auxiliary agent includes an oxidant, a cross-linking agent, an antistatic agent, a flame retardant and a lubricant, wherein the oxidant is antioxidant 168, the cross-linking agent is polyethyleneimine, the antistatic agent is borate, the flame retardant is aluminum hydroxide, and the lubricant is oleamide, the mass ratio of the antioxidant, the cross-linking agent, the antistatic agent, the flame retardant and the lubricant is 1:1:1:1:1, and the concentration of the foaming agent in the acetone solution containing the foaming agent and the auxiliary agent is 3%, and the concentration of the auxiliary agent is 1%;

[0081] Step 3: Send the stirred material into a nitrogen-assisted injection molding machine for injection molding to obtain a microporous foam material for bag dust removal, wherein the injection molding temperature is 160° C., the injection molding pressure is 20 MPa, the injection molding holding pressure is 50 MPa, and the holding time is 10 s.

[0082] The microporous foam materials prepared in Examples 1 to 6 and Comparative Examples 1 to 3 were tested respectively, and the test results are shown in Table 1:

[0083] Table 1

[0084]

[0085] According to the data in Table 1, the addition of hydrophobic modifier and talcum powder combined with nitrogen-assisted injection molding process can increase the water contact angle, reduce the adhesion of dust, and optimize the breaking strength and elongation of the microporous foam material for bag dust removal.

[0086] The roughness of the microporous foam material for bag dust removal prepared in Example 1 is reduced by more than 1.63 times, and the surface smoothness is increased by more than 1.87 times compared with the microporous foam materials of Comparative Examples 1 and 2.

[0087] 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 preparing a microporous foam material for bag dust removal, characterized in that: The following steps are involved: (1) weighing 60 to 80 parts of linear polypropylene, 5 to 15 parts of talc and 1 to 3 parts of a hydrophobic modifier by weight, mixing them evenly, and melt-extruding and granulating them on a twin-screw extruder to obtain modified polypropylene pellets; (2) adding the modified polypropylene pellets into an organic solution containing a foaming agent and an auxiliary agent and stirring the mixture uniformly; (3) The stirred material is fed into a nitrogen-assisted injection molding machine for injection molding to obtain the microporous foam material for bag-type dust removal.

2. The method for preparing a microporous foam material for bag dust removal according to claim 1, characterized in that: In step (1), the hydrophobic modifier is selected from at least one of dodecyldimethoxysilane, dodecylmethyldichlorosilane, dodecyltrichlorosilane, hexadecyltrimethoxysilane, hexadecyldimethylallylammonium chloride, octadecyltrichlorosilane and octadecyltrimethoxysilane; The fineness of the talcum powder is 200-500 meshes.

3. The method for preparing a microporous foam material for bag dust removal according to claim 1, characterized in that: In step (1), the temperature of the melt extrusion is 150-170°C.

4. The method for preparing a microporous foam material for bag dust removal according to claim 1, characterized in that: In step (2), in the organic solution containing a foaming agent and an auxiliary agent, the foaming agent is selected from at least one of sodium lauryl sulfate, lauryl phosphate, alcohol polyoxyethylene ether sodium sulfate, and lauryl phosphate; The organic solvent is selected from acetone and / or anhydrous ethanol; The auxiliary agent is selected from antioxidants, crosslinking agents, antistatic agents, flame retardants and lubricants.

5. The method for preparing a microporous foam material for bag dust removal according to claim 1, characterized in that: In step (2), in the organic solvent containing the foaming agent and the auxiliary agent, the concentration of the foaming agent is 1-5%, and the concentration of the auxiliary agent is 0.1-5%.

6. The method for preparing a microporous foam material for bag dust removal according to claim 1, characterized in that: In step (2), the volume ratio of the mass of the modified polypropylene pellets to the organic solvent containing the foaming agent and the auxiliary agent is 1 g: 1 to 3 mL.

7. The method for preparing a microporous foam material for bag dust removal according to claim 1, characterized in that: In step (3), the injection molding temperature is 150-200° C., and the injection molding pressure is 15-30 MPa.

8. The method for preparing a microporous foam material for bag dust removal according to claim 1, characterized in that: In step (3), the holding pressure of the injection molding is 10 to 100 MPa, and the holding time is 10 to 20 s.

9. A microporous foam material for bag dust removal obtained by the preparation method according to any one of claims 1 to 8, characterized in that: The contact angle between the microporous foam material and water is 150-170°.

10. The microporous foam material for bag dust removal according to claim 9, characterized in that: The cell size of the microporous foam material is 5 to 60 μm, and the cell density is greater than 10 9 / m 3 .

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