Plastic injection moulding process parts

A selection of plastic injection moulded parts.

Almost Anything

Injection moulding is one of the most widely used manufacturing processes in the world today. Look around you and you’ll probably see dozens of injection moulded parts in your wallet, kitchen, car and office. Such a widely used manufacturing process must have a fair few advantages for getting things made this way, right? Let’s have a look at some of the advantages and disadvantages of injection moulding.


Advantages of Injection Moulding


Fast Production

Injection moulding can produce an incredible amount of parts per hour. It’ll depend on how many impressions (part moulds) are in your tool, but you’re looking at something between 15-30 seconds for each cycle time.

Material and Colour Flexibility

Once you have a tool made, without lots of difficulty, you can change the material and colour of the part that you’re producing.

Labour Costs Low

A self-gating, automatic tool runs on an injection moulding machine without very much difficulty at all. Your parts can be readied with little or no labour on top of the production.

Design Flexibility

Injection moulded parts have an almost limitless amount of flexibility, you just need to be able to design around certain restrictions outlined below.

Low Waste

Most plastics recycle – we grind up all of the waste that we can and reuse it, thus reducing our waste.


Disadvantages of Injection Moulding


High initial tooling cost

As already mentioned in our injection moulding guide, there’s a high cost to entry to get a tool made for injection moulding. If you’re planning on making it yourself, you’ll need an injection moulding machine and the skills to run it, which can also be pretty expensive.

Part design restrictions

The process of injection moulding means there are some restrictions with regards to part design. You might need to make a few changes to your parts so we can make them for you – or decide on a different manufacturing technique. The most important thing to realise is that a mould tool is made from two halves that need to pull apart, and the part needs to be able to be released from the tool. This is simple, but massive. It has all sorts of ramifications down the line in terms of tool design like:

  • Each part must be made separately and be solid ie no hollow parts.
  • You’ll need to make sure you have drafting on your parts if they’re perpendicular to the tool opening.
  • It’s probably a good idea to make sure your max part thickness in any one spot is less than 2-3mm to save material and shrinkage problems.
  • We’ll try and get into the rest of these a bit later in another page.

Accurate costing is difficult

With injection moulding, as with life, there are always uncertainties that you should make sure that you budget for.

Please have a look at our injection moulding guide infographic for more information on how to get started on your injection moulding project.

If you require a personalised, approachable and reliable service from your injection moulder with the backing of years of experience in the industry, please contact us and we will be happy to provide you with a quotation or any advice you require.


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