A big consideration for this project was having a large injection capacity. In fact the largest capacity of any Precious Plastic machine to date!* Even if you never intend to make 430 gram items, what it means is that by topping up the hopper while using the machine, you can fill a mould with 50 grams of plastic every 2 minutes, without ever stopping!

*Based on market research

Let's take a moment to make a comparison. Pretend you have a shiny new mould for a 50 gram part - and two machines.

Machine A has a 100 gram shot size, plenty for your 50 gram mould. However you must remember that once refilled with plastic it will need to sit and let the new plastic melt before getting another two shots. (for the sake of this example, lets say both machines can melt fresh plastic in 6 minutes flat)

Machine B has a 400 gram shot size. That's a lot! However by the time you could fill your mould 8 times, new plastic will be melted - so it would be able to continuously fill the mould again and again with zero down time.

Let's have a look at how that might play out over a 15 minute work session.

As you can see, at the end of a 15 minute working session, a machine with 2x the capacity required for the part was able to make only four parts. While a machine with 16x the required capacity was able to make double that many parts.

It's worth noting that these are not exact figures, please don't base your business model off of this chart 😉 However it clearly demonstrates that a machine just above the required capacity is not an efficient machine for that part. Whether mass producing to sell a product, or ensuring that 40 students each get a turn - having excess capacity not only future proof's your investment against unknown larger projects, but guarantees minimal or zero downtime, waiting for plastic to melt.

Don't underestimate the importance of shot size or machine capacity!