Two factors for poor storage stability of powder coating

       Powder coating in the storage process will occur slowly changes, mainly because of powder coating production process resin, curing agent and various additives through extrusion after melting mixed together.

Therefore, after being stored for a certain period of time in a certain environment, the mixed raw materials themselves or among each other will produce some minor changes, making the powder coating unable to be used normally.

Usually beyond the storage time, powder will appear agglomeration, fluidity and other phenomena, coating film will produce abnormal luster, leveling, surface roughness and other changes.

The storage stability of powders is generally considered to be poor for two reasons.

One is the powder's physical condition has changed, this is due to the powder coatings for a long time at high temperature (close to or greater than the glass transition temperature of the powder), powder by the glass state to the high elastic state transformation, which can soften and sticky powder, showing it is powder caking or gathered themselves together, and within the fluidized drum fluidization scattered, difficult to affect the normal spraying construction.

The other involves the chemical activity of the powder has changed, because some special powder coatings add reactive extinction agent, extinction curing agent and other components, will lead to the increase of powder activity.

Under certain time temperature conditions, the powder produced a part of the chemical reaction, causing the powder deterioration, usually performance is coating film leveling and luster changes, sometimes will also make the coating film physical and chemical properties partially decreased.