At present, my country has developed into the world's largest automobile manufacturing base, and the automobile industry generally maintains a stable development trend. In recent years, under the guidance of environmental protection policies and clean production concepts in the automotive coatings industry, low-VOC and environmentally friendly coatings have become the main driving force for the development of automotive coatings. Environmentally friendly coatings represented by powder coatings and waterborne coatings have become the OEM's automotive coatings. First choice.
History and process characteristics of automotive coating process
Multi-coating system for car painting-bodywork
The multi-layer coating of automobile body mainly includes pretreatment of substrate, electrophoresis, intermediate coating, color paint, varnish, etc. Currently, powder coatings are used in varnish and intermediate coating. In the field of automotive parts, powder coatings have achieved good application results in exterior (decoration) parts, interior (decoration) parts, and functional parts.
Application of powder coatings on automobile parts
Introduce the application of powder coating in the product line of aluminum wheels and decorative parts. Three types of surface treatment processes for aluminum wheels, including fully coated wheels, fine wheels, and polished wheels, can use transparent powder in all three processes.
Powder coating automotive decorative parts spraying is mainly applied to the parts of exterior parts and interior parts. The main materials of these parts are iron parts or aluminum parts. There are two coating processes for decorative parts:
1. Pretreatment + powder coating
2. Pretreatment + electrophoresis + powder coating.
The appearance of car decoration parts pursues consistency with the overall style of the model. The external frame and the side glass jointly create a large space perspective, and the surface is perfect. The performance requirements of the coating are high corrosion resistance and high weather resistance.
The future of powder coatings for automobiles
In the field of body coatings, powder coatings will continue to develop in the application of intermediate coatings and varnishes.
Based on cost and environmental considerations. Compared with powder coating and water-based coating, the overall cost will be reduced by 1/3. This cost includes the cost of water-based waste disposal due to the low paint application rate, as well as the cost of cleaning wastewater from the paint shop. The process cost of the powder is lower because circulating air can be used in the powder spraying room. The energy cost of dusting involves air conditioning is only 1/10 of the water-based intermediate coating.
The quality and process reliability of the powder coating application: the unique orange peel characteristics of the powder on the coating surface can achieve a similar effect as the wet paint film in the high-gloss plane. The flexibility and stone impact resistance of powder coatings are better than those of waterborne intermediate coatings. The dry spray wet process of powder coating and electrophoretic paint is a direction worth exploring.
The powder coating varnish has environmental corrosion resistance, weather resistance, and scratch resistance. The coating powder coating of 40-50um is consistent with the liquid coating. At the same time, it is also making ultraviolet light curing attempts.