Automotive Painting Technology And Precautions During The Painting Process

Automotive painting technology and precautions during the painting process

Provider：Changzhou Anjia Coating Equipment Co.,Ltd

The coating part of a car is not only related to the protective clothing of the car, but also to the aesthetic level of the car. This article analyzes the automotive painting technology and the precautions during the painting process, focusing on the purpose of automotive painting, the precautions during the painting process, and the maintenance issues in the later stage.

Keywords: Automotive painting; matters needing attention

1. About Automotive Coating Technology

1.1 Automotive Painting Function

(1) Protective effect. Due to the fact that cars need to be exposed to the outdoors for a long time, it is difficult to avoid situations such as wind, sun, snow, and rain. Therefore, the surface of the car must have a certain degree of corrosion resistance, otherwise the car surface will rust and age, and in severe cases, various accidents may occur.

(2) Cars are constantly moving through our cities, and people naturally hope that cars can bring more colors to our lives. Therefore, car coatings also play a role in beautifying the environment. For this reason, modern large-scale intensive production of automotive coatings requires a significant amount of manpower and material resources to build and manage modern large-scale coating production lines.

1.2 Common Coatings for Automotive Coatings

(1) On different objects, automotive coatings can be divided into

① New car original paint; ② Automotive repair paint.

(2) Classify coatings on cars from bottom to top

① Automotive primer, mostly electrophoretic paint; ② Intermediate coating for automobiles; ③ Automotive base paint (including solid primer and metallic flash primer); ④ Automotive topcoat, generally referring to solid colored topcoat, does not require a gloss finish; ⑤ Automotive gloss varnish; ⑥ Automotive repair paint.

(3) Classified by painting method

① Electrophoretic paint for automobiles; ② Liquid paint for automobiles; ③ Powder coatings for automobiles; ④ Special coatings for automobiles, such as PVC sealing coatings; ⑤ Materials for post-treatment of painting (anti rust wax, protective wax, etc.).

(4) Classified by the location of use on the car

① Automotive body coatings; ② Paint for cargo compartments; ③ Corrosion resistant coatings for components such as wheels and frames; ④ Coatings for engine components; ⑤ Chassis paint; ⑥ Paint for interior decoration.

1.3 Basic Principles of Automotive Painting and Spray Painting

(1) Check the previous painting tools and work environment. The moisture and oil quality of the air compressor must be released first. Thoroughly clean and inspect the paint booth and ventilation network.

(2) Surface cleaning. The sprayed surface must be treated with clean water, oil, wax, and petroleum. A new welding or metal surface must be replaced with an epoxy anti rust primer to eliminate rust and prevent rusting.

(3) The correct sandblasting method. It's not too difficult to use sandpaper, try to polish it as fine as possible with sandpaper.

(4) High quality diluent. Thin, not touching the abacus, using a matching diluent, the paint can produce the highest quality, using cheap thin can save a few dollars, but it will require more time and effort; Using high-quality thin film will make work more comfortable.

(5) Curing agents and diluents. The appropriate proportion of curing agent and diluent can affect the effectiveness of the coating.

Precautions during the painting process of automobiles

2.1 Pre paint repair

In daily use, cars often suffer from simple minor injuries. If all of these localized corrosion are repaired using patching techniques, it will not only waste costs but also cause significant damage to the car coating. If the damage is not repaired and filled directly with filler, it will greatly reduce the corrosion resistance of the damaged area. Pre paint repair aims to effectively compensate for such defects. The commonly used repair methods include: soft metal filling, soft metal filling (commonly known as hanging tin) to repair surface defects of components, which has advantages such as good adhesion, simple process, and strong impact resistance. Aluminum foil resin board filling, pre coated with synthetic resin on aluminum foil containing a certain proportion of metal powder to improve its strength, has the characteristics of convenience and speed.

2.2 Sandpaper polishing

The manual polishing of the flat surface should be carried out by placing sandpaper on the hand mold board. For larger areas of polishing, they should be replaced with larger polishing boards. This not only saves labor in polishing, but also improves the quality of sanding. When polishing narrow edges and corners, it is advisable to use smaller polishing blocks. When polishing profile lines or arcs, a similar shaped imitation polishing block should be used. In the absence of polishing blocks and only using sandpaper, a typical painter would clamp the sandpaper between their thumb and palm and place it flat on the surface. The manual polishing action should be uniform and should not be applied too forcefully in order to achieve results. The direction of manual polishing should also be alternated. Otherwise, it is easy to grind out indentations, resulting in the abandonment of previous efforts.

2.3 Second oil removal

Although the surface of the car body undergoes cleaning, paint removal, rust removal, and repair processes, the dirt remaining after sheet metal repair, oil stains on tools, and oil stains on the parts of the original old paint that have not been removed will inevitably affect the adhesion of the air, and even peel off or orange peel phenomenon may occur after the topcoat is sprayed. Therefore, oil removal is still necessary before painting. It is best to use a wax remover and wipe the surface to be painted with a clean dry cloth.

Issues to be noted in car cleaning

(1) Special car wash solution should be used, and soap or detergent is strictly prohibited, as these products have strong alkalinity and can cause paint loss, color difference in certain areas, aging of sealing rubber, and accelerated metal corrosion in areas where paint falls off.

(2) Before high-pressure flushing, it is necessary to check whether the car windows and front and rear covers are properly closed.

(3) During high-pressure flushing, the water pressure should not be too high, generally not exceeding 7Mpa. And first clean the entire vehicle with dispersed mist water flow, soak it, and then rinse it with concentrated water flow. For adjustable pressure cleaning machines, during chassis flushing, the water pressure can be higher to flush out the sludge and other attached features attached to the chassis. When cleaning the car body, the water pressure can be lowered. If the water pressure and water flow during cleaning are too high, dirt particles will scratch the paint layer.

(4) When using a temperature regulating cleaning machine, be careful not to have the hot water temperature too high to avoid damaging the paint layer.

(5) When wiping cleaning agents, a soft towel or sponge should be used, preferably a sponge to prevent hard particles from scratching the paint surface.

(6) Each process of car washing should follow the principle of top-down, that is, from the roof, front and rear covers, body side, lighting fixtures, bumpers, skirts, wheels, etc.

(7) Do not wash the car in direct sunlight. If the sunlight is direct, the moisture on the car surface evaporates quickly, and the water droplets on the dried body will leave spots, affecting the cleaning effect.

(8) Do not wash the car in severe cold, as water droplets may freeze on the body of the car, causing the paint layer to break. In the northern cold season, washing the car should be done indoors. After entering the station, stay for 5-10 minutes and then rinse.

(9) If dust or impurities are found on the vehicle body, they should be removed in a timely manner to avoid staining the paint surface.

4. Pay attention to daily maintenance

(1) Before, during, and after the use of the vehicle, it is necessary to promptly remove dust from the vehicle body and minimize the adsorption of static electricity on dust.

(2) Rinse promptly after rain. After rain, the rain stains on the car body will gradually shrink, causing the concentration of acidic substances in the rainwater to gradually increase. If the rain stains are not washed with water as soon as possible, it will damage the topcoat over time.

(3) When washing a car, it should be done after the engine has cooled down. Do not wash the vehicle in scorching sun or high temperatures to prevent the cleaning agent from drying and leaving traces. Normally, when washing the vehicle by hand, special detergents and neutral running water should be used. Alkaline laundry detergent, soapy water, and detergent should not be used to prevent the oil from the paint surface from being washed off and accelerating the aging of the paint surface.

(4) To clean the vehicle, use a clean and soft cloth or sponge to prevent metal shavings and sand from getting mixed in. Do not use a dry cloth, towel, or sponge to clean the vehicle to avoid leaving scratches. When wiping, it should be gently wiped from top to bottom in the direction of water flow, without drawing circles or horizontal wiping.

(5) For some special highly corrosive traces (such as asphalt, bird droppings, insects, etc.), they should be removed in a timely manner. In this regard, special cleaning agents must be used for cleaning, and do not use blades to scrape or gasoline to eliminate it casually, in order to avoid damaging the paint surface.

Any further information, You can contact:

Changzhou Anjia Coating Equipment Co.,Ltd

Charles Pan

panye@188.com

0086 18502578856