Coating is a key process in the entire aluminum sheet and coil coating production line. The quality of the coated product, especially the apparent quality, directly affects the decorative effect of the product. Therefore, we must first grasp the common defects and causes in the coating process in order to produce high-quality coated aluminum coils. There are many reasons for the formation of a defect, and the following five factors are common:
1. Equipment
The coating line requires the coating equipment to be in good condition. The coating equipment must run smoothly without horizontal and vertical vibrations. The coating rollers must be finely ground. The lateral runout of all rollers of the coating machine must be controlled within the allowable range, otherwise it will seriously affect the surface quality of the coating.
2. Raw materials
Coatings and aluminum coils are factors that can affect the quality of coatings in the coating process. Due to the color difference between batches of coatings, the coating rate is not high due to insufficient fineness of coatings, poor coordination between coatings and solvents, layering, etc. It will directly affect the coating effect and cause defects. The unevenness of the aluminum coil substrate, uneven film thickness, and poor edge deflection will also directly affect product quality and overall use. Therefore, when aluminum coil raw materials enter the factory for inspection, the quality should be strictly controlled.
3. Production environment
The interior of the painting room is required to be clean, dust-proof, insect-proof and have a certain ventilation performance to ensure that the quality of the painted surface is not polluted. At the same time, the process conditions are changed in time due to temperature changes.
4. Human factors
The operator's sense of responsibility, proficiency in technology and standardization of operation are the keys to obtaining high-quality coating effects. Therefore, it is necessary to strengthen the training of operators and allow operators to master the principles and key points of coating technology, strengthen responsibility, and operate strictly in accordance with operating procedures to ensure high-quality coating products.
5. Craft
The coating process is closely related to the quality of the coating, and it is required to control the relative line speed ratio of the coating roller, paint extraction roller, metering roller and substrate within a certain range. According to different systems and the film thickness of the coating product, a certain viscosity range should be set for the coating to ensure the smooth progress of coating and promote the improvement of product quality. The curing process of the coating and the control of the oven must be controlled according to the requirements and must not be changed arbitrarily, otherwise the color difference and performance of the coated product will be seriously affected.
The above factors are interrelated and affect each other. Sometimes the occurrence of a defect is related to many factors, and specific problems must be analyzed in detail and eliminated one by one.
