CN114891438A

CN114891438A - Polyether sulfone composite coating applied to glass cooker

Info

Publication number: CN114891438A
Application number: CN202210471849.1A
Authority: CN
Inventors: 曾志涛; 曾志玲; 曾志盈
Original assignee: Foshan Polima Advanced Technology & Supplies Co ltd
Current assignee: Foshan Polima Advanced Technology & Supplies Co ltd
Priority date: 2022-04-29
Filing date: 2022-04-29
Publication date: 2022-08-12
Anticipated expiration: 2042-04-29
Also published as: CN114891438B

Abstract

The invention discloses a polyether sulfone composite coating applied to glass cookers, which comprises the following raw materials in parts by weight: 40-50 parts of polyether sulfone composition a, 40-50 parts of polyether sulfone composition b, 10-15 parts of tackifier, 5-8 parts of fluorine-containing composition, 3-7 parts of solvent, 1-5 parts of flatting agent, 0.5-1 part of emulsifier and 0.5-1 part of carbon black mixture; the polyether sulfone composition a comprises polyether sulfone resin, water, formamide and acetamide, the polyether sulfone composition b comprises polyether sulfone resin, water and formamide, and the tackifier comprises stearic acid amide or modified amide wax. According to the invention, by optimizing the selection and the dosage of each component in the coating formula, the coating has excellent overall effect, good adhesion with the glass surface, good heat transfer property, high temperature resistance and no adhesion. According to the invention, stearic acid amide or modified amide wax is innovatively added as a tackifier, so that the effect of improving the bonding performance of the coating and the glass surface is achieved.

Description

Polyether sulfone composite coating applied to glass cooker

Technical Field

The invention belongs to the technical field of coatings, and particularly relates to a polyether sulfone composite coating applied to glass cookers and a spraying process thereof.

Background

With the wide use of kitchen appliances, electric rice cookers have become essential kitchen appliances for households. The inner container of the electric cooker is directly contacted with food, and the food is heated by the heat transfer of the inner container, which is the core factor determining the quality of the electric cooker. The inner container of the electric cooker comprises an aluminum inner container, a stainless steel inner container, a composite multi-layer material inner container, a ceramic (purple sand) inner container and the like.

An aluminum inner container: the aluminum has uniform heat conduction, easy molding and beautiful appearance, can be compounded with other metals or alloys, is the main material of middle-grade cookware, but the aluminum liner can not be directly contacted with food and needs to be subjected to surface protection treatment.

Stainless steel inner bag: the stainless steel has excellent corrosion resistance and better intergranular corrosion resistance, the stainless steel liner can be directly used without surface treatment, but the stainless steel has poor surface non-adhesiveness and is easy to stick to a pot particularly during cooking.

The composite multilayer material liner is processed by various materials and can be basically divided into the following materials: (1) the inner surface of the composite liner is made of stainless steel, so that the requirement that the inner surface is made of stainless steel is met, and the heat-conducting property of the stainless steel is improved by utilizing the integral soaking effect of aluminum; (2) the inner wall of the inner liner is an aluminum outer layer which is stainless steel, the surface of the inner layer aluminum cannot be in direct contact with food, and surface treatment is needed to ensure food sanitation and improve non-stick property; (3) the steel-aluminum-steel three-layer composite liner is characterized in that stainless steel is seen from the inside and the outside, an aluminum interlayer is arranged in the middle, and the inner wall of the liner is made of stainless steel, so that the surface of the liner does not need to be protected, but the liner made of the composite multi-layer material is basically used in high-end products, and the selling price of the products is basically over thousand yuan.

Ceramic (purple sand) inner container: the liner made of purple sand is rich in various trace elements such as zinc, calcium and the like which are made of natural iron and beneficial to human health, the taste of cooked food is good, the surface is superhard and wear-resistant, the acid and alkali resistance and the corrosivity are strong, the heat preservation performance is good, and the like, and the cost is high.

In recent years, technicians in the field try glass inner containers, some glass inner containers are more expensive than common simple substance metal inner containers, harmful substances cannot be separated out in the use process, meanwhile, the heat preservation performance is good (the heat storage performance is good), and the odor is not easy to taint, but the existing glass inner containers are not provided with non-stick coatings, are easy to stick and stick to a pot, and are troublesome to clean, so that the research and development of the coating applied to the glass inner containers enable the glass inner containers to be good in heat transfer and good in non-stick performance, the cost of the electric cooker can be obviously reduced, and the glass inner containers have great market significance.

The surface treatment technology adopted by the existing metal liner mainly comprises the following steps: (1) spraying organic silicon anti-sticking coating on the surface of the aluminum liner; (2) the organic fluorine coating is sprayed on the surface of the aluminum liner, but the surface smoothness of the glass material is obviously higher than that of the aluminum material, so that a specific coating design is required, the problems of the bonding property of the coating and the glass, the improvement of the heat transfer property of the glass, the non-stick property of the coating, the safety of the coating and the like are fully considered when the surface of the glass is treated, and the prior art has no related technical report on the aspect and needs further research and exploration.

Disclosure of Invention

Aiming at the problems in the related art, the invention aims to research and develop the coating applied to the glass liner, and the coating has good cohesiveness with the glass surface, good heat transfer property, high temperature resistance and non-stick property by optimizing the components of the formula, thereby obviously improving the service performance of the glass liner when being applied to the electric cooker.

In order to achieve the purpose, the invention adopts the following technical scheme:

the polyether sulfone composite coating is sprayed on the surface of glass and comprises the following raw materials in parts by weight:

40-50 parts of polyether sulfone composition a

40-50 parts of polyether sulfone composition b

10-15 parts of tackifier

5-8 parts of fluorine-containing composition

3-7 parts of solvent

1-5 parts of flatting agent

0.5-1 part of emulsifier

0.5-1 part of carbon black mixture;

the polyether sulfone composition a comprises polyether sulfone resin, water, formamide and acetamide, the polyether sulfone composition b comprises polyether sulfone resin, water and formamide, and the tackifier comprises stearic acid amide or modified amide wax.

The invention relates to a coating for a glass liner, wherein a main film-forming substance is polyether sulfone resin, and the polyether sulfone is prepared by condensing 4,4' -disulfonyl diphenyl ether with diphenyl ether under the catalysis of anhydrous ferric chloride. The refractive index is 1.85, the glass transition temperature is 225 ℃, and the thermal deformation temperature is 203 ℃ (1.82 MPa). The heat resistance is between that of polysulfone and polyarylsulfone, and the long-term use temperature is 180-. The aging resistance is excellent, and the service life can reach 20 years at 180 ℃. The heat modification temperature is 200-220 ℃, the continuous use temperature is 180-200 ℃, and the UL temperature index is 180 ℃.

In order to reduce the subsequent grinding cost, the polyether sulfone resin is divided into two parts, one part is dissolved by formamide and water, and the other part is dissolved by the formamide, acetamide and water. The polyethersulfone resin is dissolved and stored in two parts, so that the storage stability of the slurry can be improved, and the polyethersulfone resin can be ground simultaneously, so that the grinding time is reduced. The fluorine-containing composition is added in the invention, so that the surface non-adhesiveness of the coating is improved, the fluorine-containing composition has non-wetting property to water, oil and most of organic solvents, has low friction to solid materials, and can obviously improve the non-adhesiveness of the coating.

The tackifier is selected in the invention, and the concrete components comprise stearic acid amide or modified amide wax. The paint for surface treatment of glass surface has better adhesion than general paint because the glass surface is very smooth, but the conventional adhesion promoter is generated by increasing the consistency of the paint, acts on the rough surface and has low applicability on the glass surface. The inventor of the invention discovers after a great deal of experimental research that the improvement of the surface smoothness of the coating can increase the bonding performance of the coating and the glass, and the stearic acid amide or the modified amide wax is innovatively added, the two substances are often used as an anti-sticking agent and a slipping agent, the use of the coating can improve the surface smoothness of the coating, and the bonding performance of the coating and the glass surface is improved.

In the invention, preferably, the polyethersulfone composite coating comprises the following raw materials in parts by weight:

polyether sulfone composition a 45 parts

Polyether sulfone composition b 45 parts

Tackifier 12 parts

6 parts of fluorine-containing composition

5 portions of solvent

Leveling agent 2.8 parts

0.5 portion of emulsifier

0.8 part of pearl powder

0.5 part of carbon black mixture.

The use amount of each component of the raw materials is a better formula obtained by the inventor through a large number of experimental adjustments, the use amount of the polyether sulfone resin, the use amount of the tackifier and the use amount of other functional additives are efficient and reasonable, and the raw materials are matched with each other to ensure that the overall effect of the coating is excellent, the adhesion between the coating and the glass surface is good, the heat transfer performance is good, and the coating is high-temperature resistant and non-sticky.

In the present invention, preferably, the tackifier comprises the following components in mass concentration: 30% of stearic acid amide or modified amide wax, 67% of water and op-103%. The tackifier of the invention is prepared by adding a small amount of op-10: the dodecyl phenol polyoxyethylene ether has excellent emulsification, wetting, diffusion and other effects, and can further uniformly disperse all components in the coating, so that the uniformity and the flatness of the coating are improved.

In the present invention, preferably, the polyethersulfone composition a comprises the following components by mass concentration: 30% of polyether sulfone resin, 23% of water, 23.5% of formamide and 23.5% of acetamide, wherein the polyether sulfone composition b comprises the following components in mass concentration: 30% of polyether sulfone resin, 23% of water and 47% of formamide. In the invention, one part of the polyether sulfone resin is dissolved by formamide and water, the other part of the polyether sulfone resin is dissolved by formamide, acetamide and water, the formamide and acetamide have good solubility on the polyether sulfone resin, and the inventor adjusts the use amount of the formamide and the acetamide after comprehensively considering the cost and the dissolving effect.

In the present invention, preferably, the fluorine-containing composition comprises the following components by mass: the carbon black composite material comprises PTFE 50%, water 47% and op-10 emulsion 3%, wherein the carbon black mixture comprises the following components in mass concentration: 27% of carbon black powder, 70% of water and 3% of dipropylene glycol monomethyl ether. PTFE is a high molecular compound formed by polymerizing tetrafluoroethylene, and has excellent chemical stability, corrosion resistance, high lubrication non-adhesiveness and good ageing resistance. Adding a proper amount of emulsion to improve the dispersion property of the polytetrafluoroethylene. The carbon black powder has the performance of low surface performance and low friction coefficient, and can improve the hydrophobicity and the wear resistance of the coating, namely improve the cleaning performance of the coating. The particle size of the carbon black powder in the present invention is preferably about 100 nm.

In the invention, preferably, the leveling agent is formed by mixing PAT-ADD RHEOL 99 and polyether modified siloxane, and the mass ratio of the PAT-ADD RHEOL 99 to the polyether modified siloxane is 2-3: 1. Further preferably, the mass ratio of the PAT-ADD RHEOL 99 to the polyether modified siloxane is 2:0.8, and the polyether modified siloxane is dipropylene glycol monomethyl ether. The PAT-ADD RHEOL 99 in the invention has excellent anti-sedimentation and anti-sagging performances, excellent fluidity and leveling property, and can improve the leveling property of the coating. The polyether modified siloxane can reduce the internal friction force and stress between macromolecules of the coating, thereby playing the roles of leveling and defoaming.

In the present invention, preferably, the solvent is prepared from acetamide and water in a mass ratio of 2:1, mixing the components. The acetamide has good solubility to the polyether sulfone resin, and the inventor adjusts the selection and the dosage of the solvent after comprehensively considering the cost and the dissolving effect.

The invention also provides a preparation method of the polyether sulfone composite coating, which comprises the steps of grinding components with solid matters in raw materials until the fineness is more than 200 meshes; larger than 200 meshes, the solid is very fine, and the surface smoothness of the coating is improved. And then mixing and dispersing all the raw materials uniformly to obtain the product.

The polyether sulfone composite coating can be used as a metal roller coating, a glass spraying coating or a molding material spraying coating with a smooth surface. The parameters of the spraying process on the glass surface are set as follows:

the working gas and the powder feeding gas are nitrogen or helium, the spraying pressure is 3-5 MPa, the temperature is 700-850 ℃, the spraying distance is 25-40 mm, the moving speed of the spray gun is 250-400 mm/s, and the powder feeding speed is 1.0 r/min-2.0 r/min. And (3) carrying out treatments such as oil removal, ultrasonic cleaning and the like before spraying the glass surface.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention researches a coating for a glass liner, wherein a main film forming material is polyether sulfone resin, and the selection and the dosage of each component in the formula of the coating are optimized, so that the coating has excellent overall effect, good adhesion with the surface of glass, good heat transfer property and high temperature resistance and non-stick property.

2. Stearic acid amide or modified amide wax is selected as the tackifier in the invention. After a great deal of experimental research, the inventor finds that the improvement of the surface flatness of the coating can increase the bonding performance of the coating and the glass, and innovatively adds stearic acid amide or modified amide wax, which are often used as an anti-sticking agent and a slipping agent.

3. In order to reduce subsequent grinding cost, the polyether sulfone resin is divided into two parts, one part is dissolved by formamide and water, and the other part is dissolved by the formamide, acetamide and water. The polyethersulfone resin is dissolved and stored in two parts, so that the storage stability of the slurry can be improved, and the polyethersulfone resin can be ground simultaneously, thereby reducing the grinding time.

Detailed Description

The technical solutions will be described clearly and completely in the following with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The raw materials in the following examples are all commercially available unless otherwise specified.

Example 1

The polyether sulfone composite coating comprises the following raw material components in parts by weight:

components	Specific Components (concentration by mass)	Number of parts
			Polyether sulfone composition a	Polyether sulfone resin 30%, water 23%, formamide 23.5% and acetamide 23.5%	40
Polyether sulfone composition b	Polyether sulfone resin 30%, water 23% and formamide 47%	40
			Tackifier	30 percent of stearic acid amide, 67 percent of water and op-103 percent	10
Fluorine-containing composition	PTFE 50%, water 47%, op-103%	5
			Leveling agent	PAT-ADD RHEOL 99: dipropylene glycol monomethyl ether 2:1	1.0
Emulsifier	op-10	0.5
			Carbon black mixture	27 percent of carbon black powder, 70 percent of water and 3 percent of dipropylene glycol monomethyl ether	0.5
Solvent(s)	Acetamide: water 2:1	3
			Pearl powder	Pearl powder	0.5

The preparation method of the polyether sulfone composite coating comprises the following steps: respectively grinding components (polyether sulfone composition a, polyether sulfone composition b, a tackifier, a fluorine-containing composition, a leveling agent, an emulsifier and a carbon black mixture) with solid matters in the raw materials until the fineness is more than 200 meshes; then mixing and dispersing all the raw materials uniformly to obtain the product

Example 2

components	Specific Components (Mass concentration)	Number of parts
			Polyether sulfone composition a	Polyether sulfone resin 30%, water 23%, formamide 23.5% and acetamide 23.5%	50
Polyether sulfone composition b	Polyether sulfone resin 30%, water 23% and formamide 47%	50
			Tackifier	Modified amide wax (micronized wax AW102) 30%, water 67%, op-103%	15
Fluorine-containing composition	PTFE 50%, water 47%, op-103%	8
			Leveling agent	PAT-ADD RHEOL 99: dipropylene glycol monomethyl ether 3:1	5
Emulsifier	op-10	1.0
			Carbon black mixture	Carbon black27 percent of powder, 70 percent of water and 3 percent of dipropylene glycol monomethyl ether	1.0
Solvent(s)	Acetamide: water 2:1	7
			Pearl powder	Pearl powder	1.0

The preparation method of the polyether sulfone composite coating comprises the following steps: respectively grinding components (polyether sulfone composition a, polyether sulfone composition b, a tackifier, a fluorine-containing composition, a leveling agent, an emulsifier and a carbon black mixture) with solid matters in the raw materials until the fineness is more than 200 meshes; and then mixing and dispersing all the raw materials uniformly to obtain the product.

Example 3

components	Specific Components (Mass concentration)	Number of parts
			Polyether sulfone composition a	Polyether sulfone resin 30%, water 23%, formamide 23.5% and acetamide 23.5%	45
Polyether sulfoneComposition b	Polyether sulfone resin 30%, water 23% and formamide 47%	45
			Tackifier	Modified amide wax (micronized wax AW102) 30%, water 67%, op-103%	12
Fluorine-containing composition	PTFE 50%, water 47%, op-103%	6
			Leveling agent	PAT-ADD RHEOL 99: dipropylene glycol monomethyl ether 2:0.8	2.8
Emulsifier	op-10	0.5
			Carbon black mixture	27 percent of carbon black powder, 70 percent of water and 3 percent of dipropylene glycol monomethyl ether	0.5
Solvent(s)	Acetamide: water 2:1	5
			Pearl powder	Pearl powder	0.8

Example 4

components	Specific Components (Mass concentration)	Number of copies
			Polyether sulfone composition a	Polyether sulfone resin 30%, water 23%, formamide 23.5% and acetamide 23.5%	47
Polyether sulfone composition b	Polyether sulfone resin 30%, water 23% and formamide 47%	43
			Tackifier	30 percent of stearic acid amide, 67 percent of water and op-103 percent	14
Fluorine-containing composition	PTFE 50%, water 47%, op-103%	7
			Leveling agent	PAT-ADD RHEOL 99: dipropylene glycol monomethyl ether 2.5:1	3.5
Emulsifier	op-10	0.7
			Carbon black mixture	27 percent of carbon black powder, 70 percent of water and 3 percent of dipropylene glycol monomethyl ether	0.8
Solvent(s)	Acetamide: water 2:1	4
			Pearl powder	Pearl powder	0.6

Example 5

components	Specific Components (Mass concentration)	Number of parts
			Polyether sulfone composition a	Polyether sulfone resin 30%, water 23% and acetamide 47%	45
Polyether sulfone composition b	Polyether sulfone resin 30%, water 23% and formamide 47%	45
			Tackifier	35% of modified amide wax (micronized wax AW102), 62% of water and op-103%	12
Fluorine-containing composition	PTFE 50%, water 47%, op-103%	6
			Leveling agent	PAT-ADD RHEOL 99: dipropylene glycol monomethyl ether 2:1	2.8
Emulsifier	op-10	0.5
			Carbon black mixture	30 percent of carbon black powder, 65 percent of water and 5 percent of dipropylene glycol monomethyl ether	0.5
Solvent(s)	Acetamide: water 2:1	5
			Pearl powder	Pearl powder	0.8

Example 6

components	Specific Components (Mass concentration)	Number of parts
			Polyether sulfone composition a	30 percent of polyether sulfone resin, 23 percent of water, 20 percent of formamide and 27 percent of acetamide	43
Polyether sulfone composition b	30% of polyether sulfone resin, 23% of water and formamide47％	46
			Tackifier	Stearic acid amide 40%, water 57% and op-103%	13
Fluorine-containing composition	PTFE 50%, water 47%, op-103%	7
			Leveling agent	PAT-ADD RHEOL 99: dipropylene glycol monomethyl ether 3:1	4
Emulsifier	op-10	0.6
			Carbon black mixture	32 percent of carbon black powder, 65 percent of water and 3 percent of dipropylene glycol monomethyl ether	0.7
Solvent(s)	Acetamide: water 2:1	6
			Pearl powder	Pearl powder	0.9

Comparative examples 1 to 3

Comparative example 1 compared with example 1, the procedure of example 1 was otherwise the same, except that an aqueous tackifier emulsion was used in place of the tackifier of the present invention.

Comparative example 2 compared with example 1, the same procedure as in example 1 was carried out without adding the fluorine-containing composition.

Comparative example 3 was compared with example 1 in the content of each component, and the other operations were the same as in example 1. The specific formulation of comparative example 3 is as follows:

performance testing

Further, in order to verify the advancement of the polyethersulfone composite coatings of the examples of the invention, the polyethersulfone composite coatings obtained in examples 1-6 and comparative examples 1-3 were sprayed on the same glass substrate under the same environment by the same spraying process, so as to keep the thickness of the paint film consistent. The paint film coatings of the above examples 1-6 were observed to have a smooth, fine and smooth surface and good gloss.

The paint film coatings sprayed on examples 1 to 6 and comparative examples 1 to 3 were subjected to performance tests under the same conditions.

Wherein, the coating adhesion test is in accordance with GB/T9286-1998, the high temperature resistance test is in accordance with GB/T1735-2009, and the target temperature is more than or equal to 300 ℃. The paint abrasion resistance test is carried out by dry grinding test by a paint abrasion resistance instrument, 3M 7447B scouring pad and a 3KG weight are used for pressurizing, and the process is repeated once and is turned over for 500 times; the paint film does not have obvious bottom penetration (the grinding mark more than 1 mm is less than or equal to 2 parts). Boiling water resistance test: and (3) boiling the coating in boiling water for 250 hours, and then testing the adhesive force of the coating, wherein the coating is qualified if the coating does not fall off. The test results are shown in table 1 below:

TABLE 1

As can be seen from Table 1, after the polyether sulfone composite coating is sprayed on the surface of glass, the adhesive force with the glass is strong, and the adhesive force of the coating is 0 grade. Meanwhile, the coating is high temperature resistant, boiling resistant, wear resistant and non-stick, and can be used as an inner surface protective coating of a glass liner. In addition, the conventional coating generally suffers damage after 200 times and 500 times of boiling rice, while the polyether sulfone composite coating can be intact for 800-l000 times.

Variations and modifications to the above-described embodiments may occur to those skilled in the art based upon the disclosure and teachings of the above specification. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

1. The polyether sulfone composite coating applied to the glass cooker is characterized by being sprayed on the surface of glass and comprising the following raw materials in parts by weight:

40-50 parts of polyether sulfone composition a

40-50 parts of polyether sulfone composition b

10-15 parts of tackifier

5-8 parts of fluorine-containing composition

3-7 parts of solvent

1-5 parts of flatting agent

0.5-1 part of emulsifier

0.5-1 part of carbon black mixture;

2. The polyethersulfone composite coating according to claim 1, wherein said adhesion promoter comprises the following components in mass concentration: 30% of stearic acid amide or modified amide wax, 67% of water and op-103%.

3. The polyethersulfone composite coating according to claim 1, wherein the polyethersulfone composition a comprises the following components in mass concentration: 30% of polyether sulfone resin, 23% of water, 23.5% of formamide and 23.5% of acetamide, wherein the polyether sulfone composition b comprises the following components in mass concentration: 30% of polyether sulfone resin, 23% of water and 47% of formamide.

4. The polyethersulfone composite coating according to claim 1, wherein said fluorine-containing composition comprises the following components in mass concentration: PTFE 50%, water 47% and op-10 emulsion 3%, wherein the carbon black mixture comprises the following components in mass concentration: 27% of carbon black powder, 70% of water and 3% of dipropylene glycol monomethyl ether.

5. The polyether sulfone composite coating of claim 1, wherein the leveling agent is prepared by mixing PAT-ADD RHEOL 99 and polyether modified siloxane, and the mass ratio of the PAT-ADD RHEOL 99 to the polyether modified siloxane is 2-3: 1.

6. The polyether sulfone composite coating of claim 5, wherein the mass ratio of PAT-ADD RHEOL 99 to polyether modified siloxane is 2:0.8, and dipropylene glycol monomethyl ether is selected as the polyether modified siloxane.

7. The polyether sulfone composite coating as claimed in claim 1, wherein the solvent comprises acetamide and water in a mass ratio of 2:1, mixing the components.

8. The polyether sulfone composite coating according to claim 1, wherein the polyether sulfone composite coating comprises the following raw materials in parts by weight:

polyether sulfone composition a 45 parts

Polyether sulfone composition b 45 parts

Tackifier 12 parts

Fluorine-containing composition 6 parts

5 portions of solvent

Leveling agent 2.8 parts

0.5 portion of emulsifier

0.8 part of pearl powder

0.5 part of carbon black mixture.

9. The preparation method of the polyether sulfone composite coating according to any one of claims 1 to 8, wherein components with solid matters in raw materials are ground until the fineness is more than 200 meshes; and then mixing and dispersing all the raw materials uniformly to obtain the product.

10. The spraying process of the polyether sulfone composite coating on the surface of glass as claimed in any one of claims 1 to 8, characterized in that the spraying process parameters are as follows:

the working gas and the powder feeding gas are nitrogen or helium, the spraying pressure is 3-5 MPa, the temperature is 700-850 ℃, the spraying distance is 25-40 mm, the moving speed of the spray gun is 250-400 mm/s, and the powder feeding speed is 1.0 r/min-2.0 r/min.