If resin and curing agent in the formula design of matching unreasonable, such as resin reactivity or the variety and dosage of curing agent selection is not reasonable, the quality percentage content of filler or volume concentration is too large, these problems will affect the physical and mechanical properties of coating, which can lead to powder coating in the coating curing is bad.
The influence of powder coating process on the poor curing of coating can be attributed to the following aspects:
The baking temperature of the oven cannot reach the baking temperature required by powder coating
While baking furnace temperature control can meet the design temperature or when no load required by the powder coating baking temperature, but the full load cases, caused by a lack of the total quantity of heat, sometimes can not meet the design temperature or powder coating the baking temperature, the temperature is low, particularly the northern region winter workshop if baking furnace heat preservation condition is poor, be before coating in baking furnace and lower temperature, by coating material thickness and thermal capacity is big, it is easier to appear this kind of problem.When the baking oven temperature can't reach the baking curing temperature of powder coating, the problem of temperature reaching the standard can be solved by increasing the heating power.In addition, you can also extend the curing time to achieve curing purpose!
In the baking oven, the baking curing time did not reach the baking time required by the powder coating
In the baking condition of powder coating, the baking time refers to the baking time calculated after the coating reaches the baking temperature, rather than the time calculated after the coating is put into the baking oven.When the coating material is thicker, the more hanging pieces, then the heat capacity of the coating is also greater, the time it takes to control the temperature of the coating is longer.In a baking oven of a certain length, the effective baking time is shorter when the speed of the conveying chain is constant.If the effective baking time is not enough, the film curing is not complete, the physical and mechanical properties of the film can not meet the requirements.Therefore, in the powder coating, it is best to use the furnace temperature tracking instrument to determine the temperature change of the coating in the oven under the condition of full load, in order to determine the reasonable curing temperature and curing time, so as to ensure the complete curing of the coating film, but also to ensure the physical and mechanical properties of the coating film.
The coated surface is poorly treated
If were not clean, coating the surface oil scale or rust is not clean, or phosphating film quality is bad, many in the surface phosphating liquid residue and so on, after powder coating adhesion of coating and substrate will be affected, at the same time will also cause the film impact resistance performance is bad, this kind of situation, must through the improvement of the coated surface processing quality to be solved.
Contact Person: Mr. Don