The extruder screw is a long, helical shaft that rotates inside the heated barrel. It conveys the plastic granulate forward, compresses it and melts it.
Design and function
A screw usually has three zones: in the feed zone it takes in the granulate, in the compression zone the material is compressed and melted, and in the metering zone it builds up even pressure. Key figures are the diameter and the ratio of length to diameter.
The barrel is heated in several zones with heater bands and cooled with blowers or water. Screw and barrel are nitrided or hard-faced so that they withstand filled and abrasive compounds.
Where it is used
Screw and barrel work in every extruder, in cable production as well as for pipes, profiles and films. As they wear, the gap between them grows and the output drops. The parts are then reconditioned or replaced.
Typical spare and wear parts
- Screws and barrels made to drawing or sample
- Heater bands and cooling blowers
- Temperature sensors and melt pressure sensors
- Thrust bearings and seals of the screw drive
- Breaker plates and screen packs
What helps with a request
- Manufacturer and type of the machine or plant
- Designation, part number or drawing of the part
- Dimensions, material and a photo of the part or nameplate
- Quantity and required date
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