Is it necessary to use a double stage mixing machine to mix PVC with additives?
This is not absolutely necessary but highly recommended to better disperse the additives. In a hot mixer, the lubricants and the stabilizers are melted and well integrated into the PVC grains. In the cold mixer (2nd stage), the dry blend is cooled down to avoid the formation of lumps. The discharge temperature of the cold mixer is generally around 40°C.
