If you work in the plastics manufacturing industry, you may have heard of twin screw extruder, machines that can mix, melt and mould plastic materials into various forms such as pellets, pipes, sheets and profiles. But what materials can this versatile machine handle? In this article we will describe some of the common types of plastic materials that can be processed by twin-screw extruders, as well as other related machines.

Firstly, let's briefly review the basic working principle of the twin-screw extruder. It consists of two intermeshing screws that rotate in a tightly fitted barrel to apply shear, temperature and pressure to the plastic material. The screws can have different geometries, lengths, pitches and profiles, depending on the desired function and material properties. The raw material is usually fed into a hopper at the back end of the machine and then conveyed along the screw passages where it is gradually heated and compressed. A number of additives, such as colourants, stabilisers, lubricants and fillers, can also be introduced at certain points in the extruder to enhance the properties or appearance of the final product. Finally, the molten or softened material exits the die orifice at the front end and can be cooled, cut or shaped depending on the specific application.

Now, let's look at what kinds of plastic materials can be processed by a twin screw extruder. In general, it can process a wide range of polymers, both thermoplastic and thermosetting. Some of the most common of these are

1. polyolefins: such as polyethylene (PE), polypropylene (PP) and polybutylene (PB), which are widely used in the packaging, construction, automotive and consumer goods industries.

2. Styrenics: such as polystyrene (PS), acrylonitrile-butadiene-styrene (ABS) and styrene-acrylonitrile (SAN), which have good impact resistance, stiffness and processability.

3. polyvinyl chloride (PVC): a versatile material with flame retardant, weather resistant and antibacterial properties, used in pipes, cables, flooring and medical equipment.

4. Engineering plastics: such as polycarbonate (PC), polyamide (PA) and polyether ether ketone (PEEK), which offer high strength, heat and chemical resistance for demanding applications in aerospace, electronics and medical fields.

5. Elastomers: such as thermoplastic elastomers (TPE) and thermoplastic vulcanizates (TPV), which combine the flexibility of rubber with the workability of plastic for seals, gaskets and soft-touch grips.

Of course, this is not an exhaustive list and there are many other materials that can be extruded with twin screw extruder, such as biobased polymers, composites, blends and alloys. It is important to select the correct combination of screw, barrel, temperature profile and process control parameters to achieve the desired quality and output. In addition, twin-screw extruders are often part of a larger system that includes other machines such as masterbatchers (which mix pigments and additives into the resin), pellet extruders (which form small particles of molten material for easy handling) and downstream processing equipment (which cuts, cools or calibrates the extruded product).

In short, twin screw extruder are powerful and versatile machines that can process a wide range of plastic materials, from simple to complex and from small to large batches. By choosing the right settings and using today's advanced technology, you can unlock the full potential of this technology to create high quality products that meet market and environmental requirements.