3D Printed Plastic Tooling

Here at Synapco, we love a challenge, so when invited by Fuji Xerox to trial a 3d plastic printed mould tool we jumped at the opportunity. The tool supplied from their 3D Systems HD 3500 was impressive with a 20-micron resolution it had a finish as good as anything Machined or spark eroded. The part we were asked to mould was far from optimum with thick and thin sections and fine details without draft of radii, basically it was a moulders worst case scenario.

Although sceptical at first, the results were very impressive with 10 parts off the first mould before we started to see heat degradation on the thin sections of the cavity; a second identical tool was trailed so we could learn how other materials might behave.

The Achilles heel of the first trial was found to be part cooling times, 3D Systems had given us moulding information so we knew what to expect, but a solution had to be found to enable water cooling of the tool for 2 reasons. Firstly we figured we could get away with more complex part designs if the tool was kept at a reasonable temperature, and secondly we could drastically reduce cycle times with a view to using the technology for small part runs of 500 or less.

Fortunately we were developing a Synapco product which needed a prototype tool and seized the opportunity to develop the printed plastic tool technology further. Our reason for wanting to trial the part is that we were having difficulty working out which grade of TPU we should be using for our product and the grade of material has a big influence on the required part design when dealing with live materials such as TPU.

We designed a tool bolster that would contain the printed plastic inserts which were printed with very complex water galleries – this wasn’t done just because we could, it was absolutely essential to ensure the hollow plastic printed insert would not collapse under injection pressure. As we expected the water cooling had a marked improvement in cycle time and tool life.

The 3D printed plastic tools proved to be a very cost effective way to test different materials, make design changes around our findings, and get another set of inserts printed. We found it was very successful and enabled make the changes required to get the aluminium prototype tool right first time. The best part was the speed of getting tool versions printed (2-3 days), and they worked out considerably less expensive than aluminium tools (1/3 of the cost with our trial).