Generally, for the type of plastic extruder, there are two kinds of plastic extruder that have to be mentioned. One is twin screw extruder and the other is single screw extruder.
Twin screw extruder
Components of twin-screw extruder
ission device, feeding device, barrel and screw, and the function of each part is similar to that of the single screw extruder.
Characteristics of twin-screw extruder
- Wear condition
Because it is convenient to open, the wear degree of threaded elements and barrel inner bushings can be found at any time so that effective maintenance or replacement can be carried out. It will not be found only when there is something wrong with the extruded products, resulting in unnecessary waste.
- Reduce production cost
When manufacturing a masterbatch, it is often necessary to change the colour, if it is necessary to change the product, open the open processing area in a few minutes, and the mixing process can be analyzed by observing the melt profile on the whole screw.
- Improve labour efficiency
As long as you loosen a few bolts, turn the handle device of the worm gearbox and lift the upper part of the barrel, you can open the whole barrel and then carry out maintenance. This not only shortens the maintenance time but also reduces labour intensity.
- High torque and high speed
The split twin-screw extruder belongs to this category, and its rotational speed can reach 500 rpm. Therefore, it has unique advantages in processing high-viscosity and heat-sensitive materials.
- Wide range of application
It has a wide range of applications and can be applied to the processing of many kinds of materials.
- High output and high quality
It has other advantages than the ordinary extruder, which can achieve high output, high quality and high efficiency.
What materials can be processed?
1. Glass fibre reinforced and hindered fuel granulation (such as PA6, PA66, PET, PBT, PP, PC reinforced flame retardant, etc.).
2. Granulation of high fillers (such as PE, PP filled 75%CaCO.).
3. Granulation of thermosensitive materials (such as PVC, and XLPE cable materials).
4. Strong colour masterbatch (for example, filling 50% toner).
5. Antistatic masterbatch, alloy, colouring, low filling blending granulation.
6. Cable material granulation (e. g. sheath material, insulation material).
7. Granulation of XLPE pipe materials (e.g. masterbatch for hot water crosslinking).
8. Mixing and extrusion of thermosetting plastics (such as phenolic resin, epoxy resin, and powder coating).
9. Hot melt adhesive, PU reactive extrusion granulation (such as EVA hot melt adhesive, polyurethane).
10. K resin, SBS devolatilization granulation.
Single screw extruder
Components of single screw extruder
The single screw extruder is mainly composed of an extrusion system, transmission system and heating and cooling system.
Characteristics of single screw extruder
1.Single screw extruder has the advantages of simple design and low price, so it is widely used.
2.The material transportation of a single screw extruder mainly depends on friction, which limits its feeding performance, and it is difficult to add powder, paste, glass fibre and inorganic fillers.
3.When the head pressure is high, the countercurrent increases and the productivity decreases.
4.The surface renewal of the material of the single screw exhaust extruder is small in the exhaust area, so the exhaust effect is not as good as the twin screw extruder.
What materials can be processed?
1. Pipe extrusion: suitable for PP-R pipe, PE gas pipe, PEX cross-linked pipe, aluminium-plastic composite pipe, ABS pipe, HDPE silicon core pipe and all kinds of co-extruded composite pipe.
2. Plate and sheet extrusion: suitable for extrusion of PVC, PET, PS, PP, PC and other profiles and plates. Extrusion of other kinds of plastics such as silk, rods, etc.
3. Profile extrusion: adjusting the rotational speed of the extruder and changing the structure of the extrusion screw can be used to produce various plastic profiles such as PVC, polyolefin and so on. It is also suitable for blending, modification and strengthening granulation of all kinds of plastics.
