How can powder coatings prevent lumps from working well?

Powder coatings have a tendency to lump at a certain temperature,
this is mainly composed of powder coatings in
resins, leveling agents and other materials
caused by thermal softening.
thermooenstic powder coating as the main film-forming resin is a low molecular weight of organic polymer.
These resins have a physical properties, at lower temperatures, it is shown as a hard and brittle glass state, when the temperature rises to a certain extent, the resin began to change to a certain degree of elasticity and produce a state of adhesion, below this temperature, the resin returned to the non-adhesive glass state, the resin glass state and the viscous state of the temperature of the transition is called the glass temperature .
different resins have different glassing temperatures
epoxy and polyester resins have glassing temperatures of about 50 degrees Celsius,
brighteners (701) have glassing temperatures of about 30 degrees Celsius, and
liquid leveling agents have glassing degrees below zero degrees Celsius.
the material addition of the low glass temperature in the powder coating formulation, the lower the glassing temperature of the system. At the time of production, the glass temperature of the powder system is positioned at approximately 40 degrees Celsius, which is the safe temperature of the powder coating lumps
increase in temperature will make it easier for powder coating products to form problems, how can we prevent powder coating lumps in our work?
first we have to establish a concept:
powder coating at a certain temperature is a natural law. To prevent powder coating lumps must be in the powder coating production of grinding powder, packaging, storage, transportation and other processes, powder coating products are below its glassy temperature
In this view, there are solutions as follows:
1) When producing polyester resins, select alcohols or acids that can increase their glassing temperature, or reduce the amount of alcohol used to reduce the glassing temperature of the resin to increase the glassing temperature of polyester resins.
2) Reduce the use of low glass temperature polymers, such as leveling agents and brighteners, in powder coating formulation design to ensure that the glassing temperature of the powder coating system is not reduced.
3) production, the broken sheet material down the steel belt should be fully cooled before entering the grinding process, grinding powder should be appropriate to reduce the feed speed, increase the air intake, imported air-conditioning air conditioning to control the grinding temperature. However, if the grinding powder before the crushing sheet cooling does not come, then the longer means will not play a very good role, may consider the method of forced cooling of the crushed sheet material for low temperature treatment, which is more effective than the addition of air conditioning
Again,
can be added anti-blocking aids
can be added anti-blocking aids, such as nano-silicon dioxide (VK-SP15) or nano-aluminum trioxide (VK-L20M) micro-powder to prevent powder particle bonding, anti-blocking agents generally and broken tablets at the same time abrasive effect.
nano-aluminum trioxide (VK-L20M), nano-silicon dioxide (VK-SP15) range of use:
1. Thermo-solid powder coating: epoxy resin system, polyester system, acrylic resin system. Epoxy powder coatings, polyester powder coatings, acrylic powder coatings, etc.
2. Thermoplastic powder coatings: thermoplastic powder coatings include: polyethylene, polypropylene, polyester, PVC, chloride polyether, polyamide, cellulose, polyester. Example PVC powder coating, polyethylene powder coating, nylon powder coating, fluorine resin powder coating, latex powder coating, etc.
nm aluminum trioxide (VK-L20M) use characteristics:
nm aluminum trioxide (model VK-L20M) for powder coating, can improve the fluffyness of powder coating, good resistance to lumps. For powder coatings used in high temperature and humidity environments, it has good storage. The amount of addition is generally 0.2-0.5%, nano-aluminum trioxide can improve the charged performance of the powder, especially when using frictional charge spray, can significantly improve the powder powder rate and solve the problem of dead end, while the gloss of the powder coating has no effect.
use of any single method can not effectively prevent the lumping of powder coatings, excessive use of one method will bring other disadvantages to powder coatings. Scientific cooperation using a variety of methods can effectively prevent the lumping of powder coatings
。