Analysis of Static Spraying Removal of Paint

Powder coatings, due to their environmental friendliness, strong adhesion and good weather resistance, have been widely used in fields such as metal furniture, mechanical equipment, building materials, and automotive parts. However, many enterprises still encounter a key problem that affects product quality during production - powder coating peeling off.

Insufficient workpiece temperature - the "invisible killer" causing incomplete powder curing

The curing temperature and curing time are the key factors determining the adhesion. The following situations will all result in insufficient powder curing, which in turn causes the coating to peel off:

  • The workpiece has not reached the set curing temperature.
  • The curing time is too short.
  • The temperature distribution in the oven is uneven.

Insufficient pre-treatment - Surface cleanliness directly determines adhesion strength

The following situations where the pre-treatment is inadequate will result in the formation of a "separation layer" between the workpiece and the powder, leading to a decrease in adhesion:

  • The oil removal was not thorough, leaving oil stains on the surface.
  • The phosphating film is uneven or the film layer is too thin.

Incompatible base materials - Different materials require the use of appropriate powders

The surface activity, conductivity and adsorption properties vary greatly depending on the substrate. Therefore, the type of powder must also be matched accordingly. For example

  • If galvanized parts use ordinary powder coating, they are prone to blistering and extensive peeling of the paint.
  • The use of indoor powder for outdoor metal components will lead to accelerated aging of the coating.

The quality of powder coatings - an important criterion for determining the extent of paint peeling

The quality of the powder itself is also a key factor affecting the spraying effect. Enterprises can initially determine the source of the problem by looking at the area of paint loss:

  • Local paint peeling: Relates more to the craftsmanship.

Insufficient solidification in certain areas
Uneven local pre-processing
Local oxidation of the substrate or abnormality on the surface

  • Large areas of paint peeling: Related to the quality of the powder

The powder formula is unstable
The purity of the raw materials is not high
Poor control during the production process

How to effectively prevent the paint from peeling off during powder coating? Improve the coating quality in four aspects

  • Ensure that the workpiece reaches the correct curing temperature and duration
  • Strictly follow the pre-treatment process to ensure a clean surface.
  • Choose the appropriate powder type based on the substrate.