plastic mould and custom injection moulding tips

A runnerless or hot-runner mould system could be considered as an extension of the moulding machine injection unit. In this case，the polymer is kept molten right up to the cavity gate by means of additional heating elements controlled by thermocouples. The working temperature of the hot-runner system is not dissimilar to that of the molten polymer being processed. In order to maintain a stable running temperature, the hot feed system is either insulated from the rest of the mould，e.g. by an air gap，or controlled by the addition of cooling channels within the immediate vicinity. The choice of method depends on the design of hot feed system adopted.  Advantages of the hot-runner mould The principal advantages of employing a hot-runner mould are: (a) reduced cycle times as a result of having a component cooling requirement only. The runner and feed system remain molten above the quickly frozen gate. (b) material savings result from having no sprue or runner systems to granulate ...

How to avoid contamination and waste in injectionmolding shop? Keeping material clean The importance of cleanliness in the plastic mould injection shop is nowhere more apparent than in the making of mouldings free from contamination. Safeguarding the material in the sack is an obvious matter， but is often ignored. Partially used sacks or containers should be re-sealed or covered and raised off the floor，in case of water or oil leaks. Material stored by the machine for use during the following shift should be raised on a pallet and covered，in case dust or dirt collect on the outside of the sacks. It is very easy to tip dirt or foreign granules into the feed hopper from a dirty sack. The lid should also be kept on the feed hopper. It often is not! It is not always realized how difficult it is to get rid of black specks in white mouldings (or white specks in black ones). One single black granule in a hopper full of white material can contaminate as many as half the mouldings that can be ...