The resin vitrification temperature is too low, the amount of filler added will cause agglomeration, these are because the price of materials has increased several times in recent years, have to reduce the cost caused by all aspects, of course, the resin vitrification temperature is too low due to price reasons.
As for the solution, without increasing the cost, adding loose agent (white carbon black) in the grinding process has improved the effect, but adding more will affect the powder rate of powder coating powder; In addition, after grinding into powder, let the powder cool and then packaging.
There is a slight choice of resin with high glass transition temperature, but the high glass transition temperature will also affect the powder flow and mechanical properties.
Powder formulations of the difficulty is that need to be within the cost control for various combinations of materials to achieve the best balance, to any side of the single wide all not line, so to find the balance point is the most difficult, and process control: premixed time, extrusion temperature and speed, thickness, powder particle size will make different control according to different requirements.
Agglomerate, summer is especially serious, and need to control costs, according to - broken pieces after cold grinding, grinding powder plus loose agent, finished powder placed cool through again after the vibrating screen (there are sixty or eighty mesh on the line), after the screen packaging box, the box is solid some more generous, try not to let powder in the storage transportation process by extrusion.
These methods, which can make a slight difference to the caking situation, are the most common pulverizing process in the past few years.
Some clients do a good job, and many old powder also know the problem of caking, so spray before screening, of course, this is his extra work, he is willing to screen, depends on your public relations work.