Plastic Processes Product Design

Plastic Processes Product Design

1. Plastic Extrusion

   • Plastic extrusion is the process where plastic is formed into a shape with a continuous profile Step by step -granules of plastic powder or granules are poured or fed into a hopper -a motor turns a thread which pushes the granules along a heater section -the heater softeners the plastic which is then forced through a die - as the plastic leaves the die it cools -the extruded product is then cut into the required length Advantages • the best way to make long products with the same profile • only requires simple dies Disadvantages • parts need to be cut to shape, assembled and drilled • not suitable for one off products (unless your one off is 50 meters long) Materials used in this process Extrusion can be used with a range of materials. As well as plastics, aluminium, wood-plastic composites and ceramics are commonly extruded

2. Injection Moulding

3. This process is normally associated with thermoplastics and used to create complex 3D shapes. Step by step • granules of plastic powder or granules are poured or fed into a hopper. • a motor turns a thread which pushes the granules along the heater section which melts them into a liquid. The liquid is forced into a mould where it cools into a shape. • the mould is the removed and the shape is left Advantages • very complex 3D shapes can be produced • high volumes can be produced with consistent quality • very fast compared to other moulding processes • little labour costs • little waste • little to no finishing of the shapes produced Disadvantages • high initial set up costs • moulds are expensive Materials used in their process • polystyrene • nylon • polypropylene (below) • polythene • ABD (below)