From DT Online
Small bench top lnjection Moulding Machines and similar equipment are available. They can be suitable for use in design and technology education to learn ablout the process and to create small items such as plastic connectors (e.g. to create structures out of canes, rods, old CDs or cut-out shapes), various small components, mounting pads, feet, handles and knobs, or to make personalised name stamps for example.
Injection Moulders have several parts in common:
- a Hopper of some means of adding the plastics granules;
- a means of heating the granules until melted;
- a way of forcing the melted granules under pressure through a small sprue into a mould;
- a mould which will withstand the heat and pressure and readily release the finished product when cooled.
Note: Moulds can be CNC.machined out of plastics or aluminium or more simply built up from layers of MDF - in each case the mould can be sprayed with silicon grease or rubbed with a soft pencil to aid release.
Shown below are Injection Moulders typical of those available. From left to right:
- coloured plastics glue sticks can be forced into simple MDF, plastics or aluminium moulds to simulate the process and produce small soft plastics pads or feet for example (threaded rod can be set into the mould to enable fixing after production);
- Injection Moulding attachments are available for a standard drillpress (which is used solely to apply the required pressure);
- small, relatively low cost, bench mounted machines are available and can be used to produce more complex products such as small plastics gears and wheels for models.
Safety Point! Working with hot plastics is always hazardous. Avoid fumes, wear personal protection and ensure the mould is clamped firmly together to prevent any leakage.