Teflon coating spraying method for stator flange machining surface

Abstract

The invention provides a Teflon coating spraying method for a stator flange machining surface. The Teflon coating spraying method comprises the steps that 1, a surface to be sprayed is cleaned, wherein the surface to be sprayed is cleaned with a flame-retardant cleaning agent before spraying; step 2, preparation of a Teflon suspension: preparing Teflon into the Teflon suspension according to the required proportion; 3, preparation of spraying of the Teflon suspension is conducted, specifically, a spraying packaging barrel is shaken before spraying, and precipitation is avoided; step 4, setting spraying parameters: setting air inlet pressure, spray gun outlet pressure and spraying distance parameters in the spraying process; 5, spraying of the Teflon suspension is conducted, specifically, the spraying device is started to conduct spraying on the face to be sprayed, and during spraying, spraying needs to be conducted once in the radial direction and the circumferential direction of the stator flange; and step 6, treatment after spraying. And the spraying uniformity is guaranteed, and then the spraying quality is well guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of generator stator processing, and mainly relates to a method for spraying Teflon coating on a stator flange processing surface, and is particularly suitable for spraying Teflon coating on a generator stator flange processing surface. Background Art

[0002] The stator flange of the generator is an important part of the stator frame. Its main function is to press and fix the stator core from both ends. The material of the stator flange is ductile iron, and its assembly surface is the machined surface. Because it is transported by sea, in order to avoid rust on the machined surface, Tectyl 506 anti-rust oil is usually applied to prevent rust. Tectyl 506 anti-rust oil is a solvent-based, wax-based long-term anti-rust product. The dry film is hard and difficult to clean, which brings inconvenience to on-site cleaning and assembly. Therefore, the customer requested that the anti-rust oil on the machined surface be changed to Teflon coating, which can play an anti-rust role and avoid cleaning. Finally, PTFE release agent / dry lubricant, model MS-143TE, was selected.

[0003] PTFE, also known as Teflon, Teflon, Teflon, Teflon, "4F", etc., is the well-deserved king of plastics. PTFE is a perfluoropolymer made by free radical polymerization of tetrafluoroethylene. Its friction coefficient is lower than almost any other material, and it has a very high oxygen index, with a limiting oxygen index of up to 95%. It is mainly used in anti-corrosion, heat exchangers, machinery, electronic appliances, medical material powders, etc. MS-143TE is a non-flammable, non-ozone-depleting release agent / dry lubricant containing a fluoropolymer suspension of low molecular weight polytetrafluoroethylene (PTEE). It can produce a uniform, dry film on the surface of the substrate, while also providing excellent surface adhesion and durability. However, its injection molding performance is relatively poor, which requires surface slip, which cannot be achieved with polytetrafluoroethylene dry film. Therefore, it is necessary to develop a spraying method so that the PTFE MS-143TE coating can be evenly covered on the surface of the substrate.

[0004] At present, our company has developed a suitable spraying method based on the characteristics of the Teflon suspension. First, the brushing method was adopted, that is, the Teflon suspension was shaken and poured on the surface of the substrate, and the Teflon suspension was completely covered on the surface of the substrate with a brush. After drying, water drops were dripped on the coating surface to verify whether the substrate was fully covered. If it was fully covered, the water drops were gently blown, and they could roll on the coating. If it was not completely covered, the water drops would penetrate into the surface of the substrate. The final result was that the water drops penetrated into the surface of the substrate, and the coating was not brushed evenly, so this method did not work. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method for spraying Teflon coating on the processing surface of a stator flange. This method overcomes the problem that the Teflon release agent / dry lubricant model MS-143TE cannot form a uniform and dry film on the surface of the substrate, thereby ensuring the uniformity of the spraying and thus well ensuring the spraying quality.

[0006] In order to realize the above technical features, the object of the present invention is achieved as follows: A method for spraying Teflon coating on a stator flange processing surface comprises the following steps: Step 1, cleaning of the surface to be sprayed: Before spraying, clean the surface to be sprayed with a flame retardant cleaning agent to ensure that the surface is free of oil, water, paint, rust and foreign matter; Step 2, preparation of Teflon suspension: Teflon is prepared into a Teflon suspension according to a required ratio, and the Teflon suspension is placed in a spray packaging barrel; Step 3, preparation for Teflon suspension spraying: Shake the spray packaging barrel before spraying to avoid sedimentation and ensure the uniformity of Teflon suspension; Step 4, setting of spraying parameters: Set the air inlet pressure, spray gun outlet pressure and spray distance parameters during the spraying process; Step 5, spraying of Teflon suspension: Turn on the spraying device to spray the surface to be sprayed. During spraying, spray once in the radial direction and once in the circumferential direction of the stator flange; Step 6, treatment after spraying: After a certain period of time after spraying, wait for the coating to dry before wiping the entire sprayed surface with a lint-free soft cloth. Wipe the entire surface until there is no red dust on the cloth when wiping with a clean lint-free soft cloth.

[0007] During the cleaning process in step 1, first use a towel dipped in a cleaning agent to scrub the surface to be sprayed along one direction, and then use clean blue paper to wipe the surface to be sprayed clean along the same direction until there is no oil stain or dirt on the surface of the blue paper.

[0008] The spraying parameters in step 4 are as follows: the air inlet pressure is not less than 0.27 MPa, the spray gun outlet pressure is 0.01-0.03 MPa, and the spraying distance is 200-300 mm.

[0009] In step 5, the spraying needs to be carried out at a constant speed according to a certain spraying speed; after spraying, it is ensured that the surface to be sprayed is not missed, does not sag, and the coating is uniform, reaching a coverage rate of 100%.

[0010] If the coating is uneven during the spraying process in step 5, the uneven area needs to be cleaned and re-sprayed.

[0011] The post-spraying treatment is performed at least 15 minutes after the spraying is completed in step 6.

[0012] When wiping in step 6, the force should be moderate, and hard objects should not be used for wiping. At the same time, avoid wiping the hard corners of the soft cloth.

[0013] The present invention has the following beneficial effects: 1. The method of the present invention overcomes the problem that the Teflon release agent / dry lubricant model MS-143TE cannot form a uniform and dry film on the surface of the substrate, thereby ensuring the uniformity of the spraying and thus ensuring the spraying quality.

[0014] 2. The method of the present invention is particularly suitable for spraying Teflon coating on the processing surface of the generator stator flange, and this method can be applied to the same series of products or similar products, summarizing good experience for the coating of similar products. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0016] Figure 1 It is a diagram of the spray surface cleaning process of the present invention.

[0017] Figure 2 (a) and (b) are diagrams showing the spraying process in the axial direction and radial direction of the present invention.

[0018] Figure 3 It is a processing diagram after spraying of the present invention.

[0019] Figure 4 This is the final coating effect diagram of the product of the present invention.

[0020] Figure 5 This is the existing painting effect diagram.

[0021] Figure 6 This is the existing spraying effect diagram. DETAILED DESCRIPTION

[0022] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0023] See also Figure 5In the prior art, a suitable spraying method has been developed according to the characteristics of the Teflon suspension. First, a brushing method is used, that is, the Teflon suspension is shaken and poured on the surface of the substrate, and the Teflon suspension is completely covered on the surface of the substrate with a brush. After drying, water drops are dripped on the coating surface to verify whether the substrate is fully covered. If it is fully covered, the water drops are gently blown, and they can roll on the coating. If it is not completely covered, the water drops will penetrate into the surface of the substrate. The final result is that the water drops penetrate into the surface of the substrate, and the coating is not brushed evenly. This method does not work.

[0024] See also Figure 6 In the prior art, a spraying method is used, and the spraying parameters are adjusted according to the spray paint, that is, the air intake pressure is 0.4-0.6MPa, and the spraying distance is 300-500mm. Finally, due to the excessive spraying pressure and the long spraying distance, the Teflon suspension is atomized and only covers a small amount on the substrate, but can be evenly distributed.

[0025] Based on the above problems, the present invention provides a method for spraying Teflon coating on a stator flange processing surface, comprising the following steps: Step 1, cleaning of the surface to be sprayed: See also Figure 1 Before spraying, clean the surface to be sprayed with a flame retardant cleaning agent to ensure that the surface is free of oil, water, paint, rust and foreign matter; first use a towel dipped in the cleaning agent to wipe the surface to be sprayed in one direction, and then use clean blue paper to wipe the surface to be sprayed in the same direction until there is no oil stains and dirt on the surface of the blue paper.

[0026] Step 2, preparation of Teflon suspension: Teflon is prepared into a Teflon suspension according to a required ratio, and the Teflon suspension is placed in a spray packaging barrel; Step 3, preparation for Teflon suspension spraying: Shake the spray packaging barrel before spraying to avoid sedimentation and ensure the uniformity of Teflon suspension; Step 4, setting of spraying parameters: Set the air inlet pressure, spray gun outlet pressure and spray distance parameters during the spraying process; Among them, the spraying parameters are: air inlet pressure not less than 0.27MPa, spray gun outlet pressure 0.01~0.03Mpa, and spraying distance 200-300mm.

[0027] Step 5, spraying of Teflon suspension: See also Figure 2, turn on the spraying device to spray the surface to be sprayed. When spraying, it is necessary to spray once along the radial direction and circumferential direction of the stator flange; spraying needs to be carried out at a certain spraying speed and at a uniform speed; after spraying, ensure that the surface to be sprayed is not missed, does not sag, and the coating is uniform, achieving a coverage rate of 100%.

[0028] If the coating is uneven during the spraying process, the uneven area needs to be cleaned and re-sprayed.

[0029] Step 6, treatment after spraying: See also Figure 3 15 minutes after spraying, wait for the coating to dry and wipe the entire sprayed surface with a lint-free soft cloth. If there is no red dust particles on the soft cloth after wiping with a clean lint-free soft cloth, it is qualified.

[0030] When wiping, use moderate force, do not use hard objects to wipe, and avoid wiping with the hard edges and corners of the soft cloth.

Claims

1. A method for spraying Teflon coating on the processing surface of a stator flange, characterized in that: The following steps are involved: Step 1, cleaning of the surface to be sprayed: Before spraying, clean the surface to be sprayed with a flame retardant cleaning agent to ensure that the surface is free of oil, water, paint, rust and foreign matter; Step 2, preparation of Teflon suspension: Teflon is prepared into a Teflon suspension according to the required ratio, and the Teflon suspension is placed in a spray packaging barrel; Step 3, preparation for Teflon suspension spraying: Shake the spray packaging barrel before spraying to avoid sedimentation and ensure the uniformity of Teflon suspension; Step 4, setting of spraying parameters: Set the air inlet pressure, spray gun outlet pressure and spray distance parameters during the spraying process; Step 5, spraying of Teflon suspension: Turn on the spraying device to spray the surface to be sprayed. During spraying, spray once in the radial direction and once in the circumferential direction of the stator flange; Step 6, treatment after spraying: After a certain period of time after spraying, wait for the coating to dry before wiping the entire sprayed surface with a lint-free soft cloth. Wipe the entire surface until there is no red dust on the cloth when wiping with a clean lint-free soft cloth.

2. A method for spraying Teflon coating on a stator flange processing surface according to claim 1, characterized in that: During the cleaning process in step 1, first use a towel dipped in a cleaning agent to scrub the surface to be sprayed along one direction, and then use clean blue paper to wipe the surface to be sprayed clean along the same direction until there is no oil stain or dirt on the surface of the blue paper.

3. The method for spraying Teflon coating on the processing surface of a stator flange according to claim 1, characterized in that: The spraying parameters in step 4 are as follows: the air inlet pressure is not less than 0.27 MPa, the spray gun outlet pressure is 0.01-0.03 MPa, and the spraying distance is 200-300 mm.

4. The method for spraying Teflon coating on the processing surface of a stator flange according to claim 1, characterized in that: In step 5, the spraying needs to be carried out at a constant speed according to a certain spraying speed; after spraying, it is ensured that the surface to be sprayed is not missed, does not sag, and the coating is uniform, reaching a coverage rate of 100%.

5. The method for spraying Teflon coating on the processing surface of a stator flange according to claim 1, characterized in that: If the coating is uneven during the spraying process in step 5, the uneven area needs to be cleaned and re-sprayed.

6. The method for spraying Teflon coating on the processing surface of a stator flange according to claim 1, characterized in that: The post-spraying treatment is performed at least 15 minutes after the spraying is completed in step 6.

7. The method for spraying Teflon coating on the processing surface of a stator flange according to claim 1, characterized in that: When wiping in step 6, the force should be moderate, and hard objects should not be used for wiping. At the same time, avoid wiping the hard corners of the soft cloth.

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