Injection moulding is a manufacturing process for producing objects by injecting molten material into a mould. This can be done with various types of materials plastic, metal (die casting), glass, rubber and other polymers. This can be used to produce anything from cooldrink bottles to engineering parts and toys.

Remember what I said about moulds being a good small business, in that context I was talking about manual moulds, this is even faster as it is an automated process but more expensive to start than simple hand poured moulds. How it works is the mould is designed (in a professional setting by an industrial designer) using 3D modelling software with SOLIDWORKS being the software of choice of the pros, a mould is then created and attached to a machine where it can churn out thousands of “copies” per hour. Or the more technical description: “Material for the object is fed into a heated barrel, mixed (using a helical screw), and injected into a mould cavity, where it cools and hardens to the configuration of the cavity.” If it sounds familiar that is how the Precious Plastic machine works we discussed before (links below).

We have actually looked at injection moulding twice before as part of plastic recycling 1 and 2.

Injection moulding as a small business
In recent years technology has advanced to make injection moulding more accessible with advancement in both 3D printing (to rapidly prototype without massive outlay) and as cheaper, even DIY injection moulding machines as we looked at before (with plastic recycling).

The question is what can a small business injection mould that would make it a viable business? First and foremost (and I am talking about this in depth next) an injection moulding machine can be used to run both a service business and a product business. In a service business the injection moulding production will be outsourced to you, you will be manufacturing on behalf of others. In a product business you will manufacture products that will be sold in a wholesale or retail environment.

I have been giving this business a lot of thought in recent years, remember I had reservations of the integrated plastic recycling system of Precious Plastic. What can you injection mould that would make this a viable small business? You see when it comes to manufacturing business your scale will guide your strategy. If you have economies of scale then you can manufacture high quantity, low margin products such as cooldrink bottles. But if you are unable to produce tens of thousands of items per hour you need to look at higher margin items. The problem in this business is that most higher margin items will still require a large machine. For example if you are making buckets that requires a big mould and a bigger machine.

The goal for a small business with a small machine can thus be described as to be able to make small items that have big enough margins and my main problem with the Precious Plastic project is that they have only so far illustrated low value items like combs, tiles (which is not really popular) and other such stuff. That being said injection moulding contract manufacturing might be something to look at if you can find a client looking for small parts like plugs, the casing can be injection moulded and can be finished by an electrical manufacturer. There are other popular items such as plastic clothing pegs, as well as more specialised stuff such as umbilical clamps.

Recycled material yay or nay?

There is something that I want to say quickly and I may get more detailed into it later, if you remember in the plastic recycling project the plastic is shredded before it goes into the injection moulding machine using a shredder or granulator (as the more industrial version is called) however in injection moulding and even in rotational moulding (used to make water tanks) the plastic granules or pellets that are to be melted (and pushed into the mould cavity) are bought from a supplier instead of collecting, sorting (and having to seperate different types of plastics) and shredding yourself. I have spent a lot of time thinking is it even viable to do the recycling because that’s a lot of work whereas if you were to buy the raw material in pellet form yes it will cost a premium per kg but minus a lot of hassle of people with trolleys outside your premises.┬áThis is one of my problems with the Precious Plastic project (I am referring to all the machines used together) it is not made for entrepreneurs it is more made for theatre to show plastic recycling but does not work as a business at scale because how much plastic are you going to have to accumulate every day to make products with.

Will the Precious Plastic machines work

The Precious Plastic project has both a injection machine and a compression machine 3 and 4 above (which uses injection and compression moulds) and these two are for small and larger types of injection moulding and these are often used in conjunction with the shredder to turn the plastic bottles into flakes and the extrusion machine to turn the flakes into pellets. Now there is no reason that these machine cannot be used on their own for example at one of my businesses we only built a shredder based on Precious Plastic plans to shred big pieces of plastic waste to smaller pieces so it could take up less space when stored. Looking at the Precious Plastic mould marketplace the biggest stuff that I see are plant pots and frisbees which are not exactly high value items nor in that much demand. If you can find something that you can make that is worthwhile then that would be great.

And so the small business question is then are you able to run a viable injection moulding business using a Precious Plastic machine? With bigger machines there are many other things to consider space, electrical current required (many are 3 phase) so you have to do your research including whether this is a viable business for you.

Image credit: Ricoh, Precious Plastic