Processing in automotive sheet metal, Jimo: What are the phenomena of sheet metal painting?

1. Sheet metal painting is a kind of automobile repair technology, which repairs the deformed part of automobile metal shell. For example, if the car body shell is knocked out of a pit, it can be restored to its original state by sheet metal, and then the deformed car metal surface can be restored to the same state as other intact places by spraying special paint. After the automobile body is corrected by sheet metal, there are still some defects that can't be made up by sheet metal work. Even if new parts are replaced, there will be imperfections. In order to be more perfect and accurate, we must make up for the defects through sculpture technology. After the car is damaged due to deformation and other reasons, its flatness, wheel angle and lines need to be scraped and polished. This formula shows that scraping = restoring body skin = die product = die processing program. Any car body skin is stamped with a mold, and we repair the car body skin just like repairing the mold, so our scraping molding process should be connected with the mold processing, which is impossible for ordinary painters. 2. For cars, sometimes it is inevitable to make a sheet metal. 1. automotive sheet metal is a technical means of automobile repair. In this respect, automotive sheet metal is equal to the repair of automotive sheet metal, which means that the car body should be repaired after the collision, that is, all the work except the anti-corrosion and decorative spraying of the car body. Such as body damage analysis, body measurement, body sheet metal shaping, stretching correction, stress relief welding, body accessories assembly adjustment, etc. Second, automotive sheet metal is a processing method of automobile maintenance, also called cold working. To put it bluntly, if the appearance of the car body is damaged and deformed, the sheet metal process is needed. Automobile collision repair has developed from the initial "welding repair" to the secondary manufacturing and assembly of the car body. The repair of vehicles in collision accidents is no longer a simple automotive sheet metal knock, and the quality of repair can not be observed only by naked eyes. Maintenance personnel should not only know the technical parameters and dimensions of the car body, but also master the characteristics of the car body material, the transmission of force characteristics, the deformation trend and stress points of the car body and the production technology of the car body such as welding technology. On the basis of mastering this knowledge, maintenance personnel should also use advanced measuring tools and accurate three-dimensional measurement of the car body to judge the direct and indirect damage and deformation of the car body and the hidden dangers caused by the deformation of the car body, formulate a complete car body repair plan, and then cooperate with correct maintenance technology and accurate three-dimensional data of key points to restore the car body to its original position and restore the damaged car body to the factory state. Third, in short, automotive sheet metal is to completely repair the damaged car body: the general process is as follows: 1: Dismantle the whole car (it will involve, or remove all the sheet metal parts from the parts where painting work is carried out); 2. Car body repair (replacement, stretching, welding and other repairs caused by impact or overturning, such as iron plate depression, beam bending, dimensional displacement, etc.); 3. Repair of sheet metal parts (all damaged sheet metal parts that should be repaired should be bonded and welded to restore appearance and size); 4. Face repair of sheet metal parts (sheet metal parts such as car door lights and non-sheet metal parts such as displaced mechanical appliances after replacement and repair need superb skills and unremitting patience to achieve accurate and beautiful installation); 5. Vehicle installation (after painting, all sheet metal parts are installed and fixed, and all movable sheet metal parts are tested); 6: Complete the factory. Then there is painting, that is, coating a layer of paint on the surface of the car to protect the car. Baking varnish is generally used for automobile painting. In the automobile factory, the frame and shell are welded, and the next process is painting. The forms are common paint, metallic paint and pearlescent paint. Automobile painting process: putty scraping, polishing and painting. Its basic process: (1) body rust prevention and internal painting: completed by the sheet metal worker according to the body condition. (2) Polishing and trimming the bevel edge: Use P60~ 180# sandpaper to polish the parts of the car body that need putty after being repaired by sheet metal. (3) Dust removal and cleaning: use pressure gun and desilication cleaner to remove dust and stains on the car body. (4) Sticking: Sticking textured paper with reverse sticking technology. (5) Priming: mix 4: 1 red primer, spray 1~2 layer to expose metal, and then dry. (6) Filling putty: Fill the concave position on the car body with mixed multifunctional putty and leave it at 20 degrees Celsius for 30 minutes. (7) Polishing putty: Polishing putty with P60~240# sandpaper, and checking smoothness, pinholes and traces with hand feeling or polishing indicator layer. (8) Extra-young putty: choose it when necessary to fill pinholes, sandpaper marks, etc. (9) Polishing: Use P280# sandpaper to thoroughly polish the old paint that needs to be sprayed with intermediate paint. (10) Dust removal and cleaning: use pressure gun and desiliconization cleaner to remove dust and stains on the car body. (1 1) Sticking: Sticking masking paper. (12) Spraying intermediate paint: mix 2~3 layers of multifunctional intermediate paint, with an interval of 5~ 10 minute for each layer, then dry at 60 degrees Celsius for 30 minutes, and then spray the polishing indicator layer. (13) Polishing intermediate paint: polish the dried intermediate paint with P320~400# sandpaper. (14) Inspection: Check the grinding effect and carry out micro-filling. (15) Dust removal and cleaning: remove dust and stains from the car body. (16) Paste: Paste the shielded car body. (17) Dust removal and cleaning: firstly, blow out the dust spots on the car body with a pressure gun, remove the stains on the car body with a desilication cleaner, blow out the dust in the gaps of the car body with a pressure gun, and finally remove the dust on the car body with a sticky dust cloth. (18) plain paint spraying on top coat: spray 2-3 layers, with the interval of 5-10 minute for each layer, and add curing agent and diluent according to the temperature. (19) Primer spraying: spray 2-3 layers of plain paint, silver powder paint or pearlescent paint with an interval of 5- 10 minute. (20) Spray painting: mix and spray two layers of varnish every 5- 10 minute, and add curing agent and diluent according to the temperature. (2 1) drying: let stand for 5~ 10 minutes and dry at 60℃ for 30 minutes. Drying and curing need to be judged. If you feel sticky with your fingers, the surface is dry; If there is no fingerprint to the touch, it is semi-hard; If you don't have a fingerprint, click it and it's completely dry. (22) Waxing and polishing. (23) build a car. The purpose of building a car is to prevent the spray from spraying where it should not be sprayed. The traditional basic covering materials are covering paper and covering tape. The width of automobile cover paper ranges from 7 cm to 9 1 cm, which is heat resistant. Generally, it can be used safely in the drying room, with good wet strength, which can prevent solvent penetration (note: newspapers cannot be covered with newspapers, which are not heat-resistant and contain printing ink, which will dissolve in the paint solvent and penetrate into the topcoat below, causing pollution).