Processing of Plastics

Plastics are processed differently depending on the material and application. Some common methods are: Extrusion Compression moulding Injection moulding Foaming Extrusion In this process thermoplastic material is melted and is continuously forced through a tool via a worm screw. The extruded bar is then calibrated, cools down and is withdrawn via a take-off unit. Compression moulding Thermosetting material is poured into the open compression mould in powder form. Under the impact of the mould pressure and heat, it then chemically reacts and solidifies to the desired finished part. Injection moulding Thermoplastic material in granular or powder form is gradually melted in the cylinder and the mass is injected by means of the worm screw into a mould under high pressure. The plastic then solidifies and is ejected from the mould as a finished part. Steam Foaming Granular plastic containing a blowing agent is injected into the mould, expanded by means of hot steam, cooled with water and ejected from the foam mould as an extremely light weight part. Water absorption is impossible as all pores are closed.  ...