How to solve the black spots in pellets during plastic granulation process

The problem of black spots in pellets during the granulation extrusion process is a common failure phenomenon, especially on colored and light-colored products.In order to effectively avoid the harm of carbonization of plastic products, we need to understand the nature of carbonization and be good at using effective methods to solve and prevent carbonization of plastic products.

To quickly clean the carbide in the plastic granulation extruder, it is necessary to use harder plastic or its recycled material together with white mineral oil for cleaning, and the temperature should be increased by 10-15°C.Meanwhile, it is necessary to consider the plasticizing ability of the small plastic granulation extruder .For large and medium-sized plastic pelletizing extruders, ultra-high molecular weight plastics or their recycled materials can be cleaned with white mineral oil.Since ultra-high molecular weight plastics have better hardness, when the temperature is higher, the cleaning object will be softened and easy to fall off, which is conducive to the carbide being carried out by the melted plastic.During the cleaning process, the plastic pelletizing extruder switches repeatedly between low speed and high speed.If the motor load has a margin, it can be stopped and restarted repeatedly during the operation to further improve the cleaning effect. When the carbide (black spots) in the melt is obviously reduced, it can be cleaned with ordinary plastic until it is clean, and gradually adjusted to an appropriate temperature, then normal production can be achieved.