Summer is coming, and powder coatings often have agglomerates or even agglomerates when they are used. This is because during production, storage, and transportation, the ambient temperature is high and the humidity is high, and the glass transition temperature of the powder coating is more than 40 degrees. In order to prevent the powder coating from agglomerating and agglomerating during the application process, the following aspects should be paid attention to:

1. When selecting resins, select some resins with high glass transition temperature (TG). The glass transition temperature of conventional epoxy resins and polyester resins is about 50°C, which can meet general needs. When the storage requirements are high, the use of alcohol that will lower the glass transition temperature of the resin can be reduced when the resin is synthesized, and the cured epoxy can be cured with alicyclic amine.

2. Reduce the amount of low glass transition temperature polymer used in powder coating formulation design, such as leveling agent and brightener, the glass transition temperature is about 30 ℃, you can add a little less. The addition of plasticizer will reduce the rigid group of the resin and reduce the TG of the resin. Excessive addition of TGIC will also reduce the TG of the resin.

3. The auxiliary additives are internally squeezed dry powder flow agent and external anti-caking agent, white carbon black. The main component of the dry powder flow agent is some anti-blocking wax powder organic matter, and the anti-caking agent is mainly an inorganic substance such as silicate. It is crushed and sieved together with the flakes to prevent the powder from sticking to the block. The added white carbon black is mainly vapor-phase method, light specific gravity, easy to absorb moisture. Therefore, when using it, it should be dispersed well to avoid moisture, and there will be no white spots when the color is added.

4. The production process mainly controls two links, extrusion and milling. When extruding, the long track and the fan are used for physical cooling, which can effectively reduce the temperature of the flakes. After the flakes are cooled, they can be ground. When grinding powder, the feeding speed can be reduced, and the induced air volume can be appropriately increased. If conditions permit, a cooler can be installed at the air inlet to reduce the temperature in the pipeline. The ground powder should be cooled to below room temperature before packaging. Some powder factories will separate and pack a box of powder with two inner bags, which is also to prevent the accumulation of powder and to prevent the powder from agglomerating to a certain extent.

5. The powder should be stored in a dark and dry workshop. Some products with high gloss and floating flowers that are easy to agglomerate need to be stored in an air-conditioned warehouse, or a layer of aluminum foil should be wrapped around the product for heat insulation. For transportation, use air-conditioned vehicles or trucks covered with shade cloth instead of box-type trucks. At the same time, avoid heavy loads.

Conclusion: It is a natural process that powder raw materials are easy to agglomerate when encountering high temperature, and it is not necessarily an index to evaluate the quality of raw materials. In addition to high temperature and agglomeration prevention, fire prevention and disaster prevention are also important. Similar to the prevention of smoking in the workshop, the prohibition of electric vehicle charging, and the exposure of equipment threads, small negligence causes major problems. 

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