The reason of pre-compacting is to reduce volume and guide the residues to the feeding-chamber where the piston drags the residues into the press-cylinder for compacting. See working scheme below; the main parts for pre-compacting are screw (01), funnel (02) and feeding chamber (03).

Following some advantages of the BIOMAX equipments:

- Feed-screw with adjustable angle
- Feeding-chamber with cooling system
- Feed-screw with special outflow
- Stronger screw support
- Special formed feeding chamber