The new mold of the biomass pellet machine will have burrs inside the mold due to its processing technology. These burrs will affect the extrusion of the pellets. At this time, the mold needs to be washed, which is also called grinding. 

When washing the mold, you need to use abrasives. There are three main components of abrasives: materials, fine sand and waste engine oil. The ratio between them is material 1, fine sand 2, and waste engine oil 1. Use a shovel to mix thoroughly.