Why don’t you use air pressure to move the piston ?
It is a way to have high pressure with initial pressure about 8 bars, using surpressor process : with 2 sections you can generate high pressure : P1 = (P2xS2) / S1
P1 : pressure for injection
P2 : initial pressure from compressor ( 8 bars )
S2 : section of first piston (this piston move with de 8 bars from compressor)
S1 : section of second piston (this piston push the plastic for injection)

Erwan from, and very interested to PET recycling.

Hello guys

I have seen a lot of good ideeas here, so, I consider that is fair to share 🙂
Here is my design on injection.

It needs an excentric clamping to enshure the tight fit bettwen the press and mould (is in design) and I hope to find a pneumatic piston for it.

Feel free to wright any oppinios, please 🙂

Hi win,

that’s another item for the ‘to do’ list…. Pretty busy in the PP workshop lately 😉

We did n’t give it a try yet.
For the latest machine we focused on a redesigned manual one.

Injection Version 2.0

A couple of machines finished this week, so perhaps we have time in the next weeks…

Regards Kees

Hi Kees,

I look forward to your updates, I was given a pneumatic ram years ago with 63mm Ø x 500mm stroke, unfortunately it’s sat outside in the weather for the last few years. If you have success I may also build a pneumatic injection moulder. The best of luck 🙂

The injector with the bicycle parts is finished, so time to start with a other option.
The main part arrived yesterday by mail 🙂 a 40mm*540mm cylinder.

I keep you posted if it works ………

Well, it seams that pneumatic pressure wont cut it 🙂
I have just spoken with some guys from Harting, it turns out that pneumatic pressure is a no no.
I was thinking maybe a step by step motor from a regular printer would do the job.
Of course, it will need assistence from a pc and a screw

We’re currently experimenting with different pressing techniques as well. We haven’t tested pneumatic yet, we started doing it manually because of the speed. But pneumatic is definitely on our “thing to try out” list. If you are going to try it out, let us know your how it went!

Hi Dave
In this moment it is 300x300x360 mm
I have to decide how to assure sealing between nozzle and mold … I m thinking of a eccentric system
The piston will be driven penumatic or by leverage , still trying to make my mind 🙂

Hi thanks for sharing @mariam, looks great so far. What size are you going to make it?