Page 20 - Demo

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Figure 21 — Injection mould gate marks
This method is is is utilised to manufacture thin- walled plastic parts used in in in in a a a a a a a a range of different functions The thin walls reduce cooling time time allow for faster cycle times and in in in in turn a a a a a a a a a significantly cheaper product The thin walls can can be seen in in in in the the the housing of the the the drill in in in in figure 22 You can see see ribs and and bosses throughout the the the part to provide support and and structure A
material is is is selected for a a a a a a a number of of reasons The most important is is is the the required characteristics of of the the the the final product But consideration must also be given to how the the the the material will react during the the the the manufacturing process The table on
the the the the following page (figure 23) illustrates the the the advantages
advantages
and and disadvantages of of the the the the polyurethane (drill casing) and and and some of of the the the the other most common plastics used for injection moulding and and their applications Figure 22 — Injection mould walls Plastics can also be integrally moulded together to to to create desired properties which would otherwise be impossible to to fabricate using a a a a a a sole plastic plastic The table (figure 24) on
the the following page illustrates a a a a a a a a variety of combined plastics and their properties