1. Feeding System:
- Hopper: The material is fed into the machine through a hopper, which is typically designed to handle both virgin and recycled PVC materials, including powder, flakes, or small pieces.
- Feeder: A screw feeder or belt conveyor may be used to control the rate at which the PVC material enters the granulating process, ensuring consistent throughput.
2. Extruder:
- Single or Twin-Screw Extruder: The core of the machine is an extruder, which can be either a single-screw or twin-screw design. The extruder heats, melts, and mixes the PVC material, preparing it for granulation.
- Barrel and Screw: The barrel contains the screw(s) that convey the PVC through the machine. As the material moves through the barrel, it is heated and compressed, which ensures uniform melting and mixing.
3. Cutting System:
- Die Head: The molten PVC is forced through a die head that shapes the material into strands or spaghetti-like extrudates.
- Rotary Cutter: The strands are immediately cut into granules by a rotary cutter or pelletizer, which chops the extrudate into small, uniform pellets as they exit the die head.
4. Cooling System:
- Air or Water Cooling: The freshly cut granules are usually hot and need to be cooled quickly to retain their shape. This can be achieved using air cooling (blowing cool air over the granules) or water cooling (submerging the granules in a water bath).
- Dryer: If water cooling is used, the granules are then passed through a dryer to remove any moisture before packaging.
5. Screening and Classification:
- Vibrating Screen: The granules are passed through a vibrating screen to remove any oversized or undersized particles, ensuring that the final product is uniform in size.
- Classification: Granules may be further classified based on size or other specifications before packaging.
6. Collection and Packaging:
- Collection Bin: The finished granules are collected in a bin or container, ready for packaging.
- Packaging System: Depending on the production setup, the granules can be automatically weighed, bagged, and sealed for transport or storage.