Page 19 - Demo

Aluminium’s low-grade mechanical properties are vulnerable to to abrasion damage and distortion during the the the injection process Although they do have the the the the the advantage cost effective output in low-volume production On the the the the the other end of the the the the spectrum steel moulds are very expensive But with high high price comes high high quality these moulds are able to generate over a a a a a a million parts in their life cycle [5]
Figure 19 illustrates a a a a a multiple cavity mould mould For the the the plastic to to flow into the the the mould mould cavities numerous channels are incorporated in in in in in the the the mould mould design The liquid plastic injects into the the the the mould mould by way of the the the the sprue This leads to to the the the the the the runners these are channels that that transport the the the the the plastic to to all the the the the the cavities that that will be filled The The runners connect to to to the the the the the gate which guides the the the the flow to to the the the the part The The The blue dots in in figure 19 illustrate the the the the the cooling channels These allow water to pass over the the the mould walls and cool cool the the the liquid plastic Figure 19 — Mould channels [4]
After the the the part is cooled and ejected from the the the mould the the the the post processing procedure will occur The runner sprue and gate which form in in the the the process are all by products of the the desired part These as as as as well as as as as any flash that has occurred during the process will need to be trimmed Figure 20 — Injection moulded part [4]
Figure 20 shows a a a a a a moulded part before and after the trimming process The excess plastic that is is trimmed off can be recycled in in in in in most cases It is is placed placed in in in in in a a a a a a a a a a a grinder and ground into into granules that can be placed placed back into into the the hopper to to to repeat the the injection process It It is hard to completely remove the the the marks that are left from the the the the gate in in the the the the injection process process It It can be achieved but the the the the process process is very expensive Instead the the the the imperfections are usually hidden on on on the the the the inside of parts and once once the the the the product is fully assembled the the the the the defects are are concealed The plastic injection injection parts from the the the drill are are displayed on on on on the the the next page (figure 21) with circles around injection injection injection points points All these injection injection points points are concealed once the the drill is assembled [4]
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