Metallic Spray Paint process, the powder coating after the flow through the air flow to the gun, the gun through the high-voltage electrostatic generator, in the nozzle of the electrode needle corona discharge, near the electrode produced a dense negative charge, the powder spray from the tip , The charge is charged as a charged powder, in the air, electric field and its own gravity under the action of flying to the ground workpiece, and adsorption on the profile surface. Therefore, in our spraying process, the need to do adequate preventive measures.
1, Metallic Spray Paint method
In most cases, it is sprayed with an electrostatic spray gun. Since this type of product contains metal pigments, it is necessary to ensure a good grounding of the system when spraying with an electrostatic gun. At the same time, a lower static voltage and a powder amount are set to prevent spraying The phenomenon of ignition. The effect of forming a coating film is greatly related to the setting of the gun, the quality or the brand. After a long period of spraying may have a large number of metal powder accumulation in the gun discharge needle, need to spray the regular cleaning discharge needle.
2, the Metallic Spray Paint luster
In most cases, due to the large error, it is not recommended to use a gloss meter to measure the appearance of the appearance of the coating film, but only use visual comparison method to determine whether the same with the standard model.
3, the recovery of Metallic Spray Paint
For the powder made by dry mixing method, the separation phenomenon occurs in the process of spraying and recycling, so there will be some difference in the content of the metal powder in the recovered powder and the new powder, which may lead to the inconsistency of the appearance of the coating film. The This is due to the difference in the nature of the metallic pigment and the powder particles. Experts recommend that the ratio of recovered powder to new powder is at least 1: 4. If the powder coating produced by the bond fixing method is used, the recovered powder can be completely reused due to the relatively constant ratio between the metallic pigment and the powder particles.
4, Metallic Spray Paint of the coating layer
The coating of the Metallic Spray Paint on the coating layer has the following advantages: to enhance the anti-stone coating performance of Metallic Spray Paint; increase the aesthetic effect of Metallic Spray Paint; completely solve the metal pigment can be erased; improve the Metallic Spray Paint The weatherability. In order to ensure the appearance of the cover layer effect, requiring the first spray of the workpiece can not be any pollution. Therefore, the need for a fully automated spray line and two separate spray booths were sprayed. It is recommended not to spray the coating under normal circumstances.
5, the metal pigment can be erased
Whether it is dry or mixed with a fixed method of making the powder, can not completely solve the problem of metal pigment can be erased. The only way to solve the erasability is to spray a layer of clear coating on the Metallic Spray Paint.
6, try to keep the stability of the spray conditions
Use the same set of spraying equipment, using the same voltage, air pressure and other parameters; try to keep the gun and the workpiece from the same, as far as possible to maintain the stability of the film thickness; to ensure that the powder coating before spraying has been fully fluidized; use of recycled powder, Powder to the ratio of new powder to less than 1: 4; try to avoid the use of Metallic Spray Paint spray type complex or there is a deeper depression of the workpiece; recommended for the assembly together for a number of parts should be sprayed at the same time.
(Cold-rolled plate, hot-rolled plate, galvanized sheet, aluminum alloy, glass fiber reinforced plastic, etc.), the surface condition of the workpiece (corrosion, corrosion, corrosion resistance, etc.), according to the specific conditions, such as the location of the plant space, Anti-rust oil, debris), production volume, quality requirements and other options. Different manufacturers use different processes. Such as passenger car production of the overall process and quality requirements are basically the same, pre-processing process generally have the following two:
1, pre-processing parts
Typical process: pre-degreasing → degreasing → washing I → pickling → washing II → medium and → washing III → → → →
Manufacturers can be based on the actual situation of the factory to make appropriate adjustments:
As a pre-treatment, pickling rust is essential. However, in the pre-treatment process, it is best to separate the corrosion parts and non-corrosion parts, rust pieces for pickling, non-corrosion parts is best not to pickling.
2, product pre-treatment
Product pre-treatment is the entire product immersed in the bath for surface treatment, there are many manufacturers have adopted. There are two kinds of manual control and automatic control. More advanced is the use of PLC program automatic control, to achieve automatic transfer between processes. The general process is: degreasing → washing → tune → phosphating → washing.