powder coating curing

Three, powder coating curing temperature and time

The curing process of plastic powder is a

chemical crosslinking process. The ideal curing conditions of epoxy polyester powder

coating are: 180 C, 20min (there are other curing conditions, see the specification).

the curing temperature is too high, and the time is too long, there will be the phenomenon

of coating aging, white coating aging will be yellowing. If the curing furnace design is

not appropriate, the temperature is too high, will appear in the local yellow phenomenon;

at this time, should increase the hot air circulation system, and adjust the temperature in

a suitable range. General coating aging. Some manufacturers heating up time is too long, up

to 180 degrees from room temperature to degrees Celsius, to 180 degrees after 20 minutes of

constant temperature, so that it is easy to over curing, should make the oven sealed

insulation, heating time in 20-40 minutes for easy. And the internal hot air convection,

the temperature is even.

The far infrared heating tube heats up, should pay attention to the

same workpiece heating tube distance (not less than 200mm), if the site is too close, white

coating easy overbake and yellowing, add a piece of iron between the workpiece and the

heating pipe (thickness 1.5-2mm), steel plate drilling, this can reduce the "roast yellow

may.

For the coating curing temperature is too low or too short, then crosslinked membrane

is not complete, poor adhesion of the coating, the sub light, no ray is reflected in the

gloss is too high, poor adhesion. Such problems, only once again reasonable curing can get

qualified products.