The coating of the barrel of the extruder: it is required to cover the insulation layer and the heater area with metal sheets to protect the operator from contact with the high temperature surface. The insulation layer can also reduce the convective heat loss in the machine room. The length of the cladding metal sheet should be shorter to reduce the weight of the operator when disassembling.
Extruder Screw: The feed screw is a screw propeller designed to provide the resin to rotate under the required process conditions. Most of the screws are machined from alloy steel and subjected to stress-relieving heat treatment for maximum dimensional and strength stability. The tip of the screw helix is hardened by heat treatment, spraying or welding to reduce wear. It is desirable to make the barrel lining material harder or more abrasive than the top of the spiral, thus making the spiral tip a victim of friction, as it is easier to update the worn outer diameter of the screw than to update the inner diameter of the barrel. The matching screw tip and barrel material should be properly selected to ensure durable use. Alloy steel screws usually have a protective layer of 0.025 mm chrome or nickel to prevent rust, facilitate cleaning, and resist corrosion and flame retardancy of polymers such as vinyl chloride. The screw passes through the depth of the feed zone. To ensure the characteristics of the feedstock and prevent bridging caused by premature melting, a set consists of a two-way rotary pipe joint (which has a water inlet pipe connecting the screw and possible water) A device for generating a return pipe that is discharged by water vapor. The flow metering valve controls the amount of water that is cooled. In order to replace, inspect or clean the screw, a manual or hydraulically operated lifting tool is required to push the screw end from its transmission interface.
Click here to view Previous or Next