Page 18 - Demo

INJECTION MOULDING
Injection moulding is is commonly utilised for manufacturing a a a a a a a a a a a a vast array of of plastic parts with a a a a a a a a a a a a a a a wide range of of of shapes and sizes During the deconstruction process a a a a a a a a large number of of parts in in in the the assembly were found to be be produced by the the injection injection moulding moulding method Materials that are suitable for injection injection moulding moulding range from metals where the the procedure is called die casting to the the most common application of plastics plastics Thermoplastics such as as as polystyrene nylon polypropylene and polythene are best suited for the the the process as when heated to a a a a a a a a a a specific temperature they become malleable and are easily pushed through the the injection injection unit A typical injection injection moulding machine is illustrated in in figure 17 below [13] Figure 17 — Internal Moulding overview [4]
The whole process is very quick normally between 2 2 seconds and 2 2 minutes The procedure (refer to to figure 15) can be broken down into four stages:
1 The process begins with granules of plastic powder poured or fed into a a hopper 2 The plastic is heated in in in the injection unit tube and once a a a a a a a a predetermined temperature is is reached the the screw thread thread starts turning The thread thread is is powered by a a a a a a a motor situated at at the the the end of the unit 17 3 As the the the motor turns it pushes the the the plastic (still in granules / powder form) along the the the heater section where it changes to molten plastic 4 Now in in liquid form the the plastic is is forced into the the mould mould where it is is allowed to to cool and and solidify When hardened the the mould mould opens and and the the finished product is is removed Figure 18 — Injection Moulding process [5]
Depending on the product to be be manufactured a a a a a a a a mould mould may be be single or multiple multiple cavity cavity A multiple multiple cavity cavity mould mould can consist of identical cavities producing numerous numerous matching parts or or they can be unique and form numerous numerous different geometries during a a a a solitary process The product to be produced will determine the the material of of the the mould Tool steel steel which is a a a a a a a a a a a a variety of of carbon and and alloy steel steel steel are most common but aluminium aluminium and and stainless steel steel also have their place The problem with aluminium aluminium moulds is is that they do not consistently produce quality parts in high volume production