So I am interested in trying some compression part molding here with the 2 peice male/female molds and then a bolt together. I have the female made but am wondering how I should go about making the male side. I am assuming I should make a part and then build a mold on top of it but won’t the compression form bolting be greater than that from vaccumm, thus requiring a larger male mold? Anyone have experience with this, I am planning on wetting out before compression as RTM does not sound like fun!
You will need to lay up a part or better yet, get tooling making machined sheet wax to simulate the finish part viod area. Then make your top half mold…
What werks said as it is a 100% needed step.
By the wat RTM is the bomb. I wouldnt be afraid of it. The equipment seems expensive, but, Im guessing there are poor mans versions of it also.
I had a great conversation about it with the guy who set up Peterbuilts molds. He simplified it for me, went over the mold building steps. Not so difficult once its explained.
RTM? = infusion?
The RTM positive pressure process using 2 piece moulds works very well indeed, and its quite possible to make things like carbon motorcycle engine side cases using this method.
For making large numbers of a single part, after the extra mould costs have been covered, its also cheaper and faster than vacuum infusion, and cheap and simple pumps can be used for single moulds.
So what all would be involved in a cheap version of this process???
Here is what I am thinking.
-make a slightly thinner version of part I am currently making via bagging.
-make an outer mold of this guard with room for an inlet at each end. Ensure both guards are thick and holes are large enough for just an inlet tube.
-Make bolt-holes to allow bolting molds together.
-put in reenforcements, bolt the mold together with tubes in a hole at each end.
-put putty around outside to ensure seal.
-pull vaccuum on one tube while sucking in resin via the other. Essentially vac infusion but using pressure rather than vaccuum to hold down reenforcement.
Would this work?
Is there an easier way to do it without requiring a vaccuum be pulled?
Using a gasket of some sort between the two parts of the mould tool, would be a good idea.
If the parts you want to make are relatively small, there is no need to use vacuum at all. Just inject a suitable RTM resion into the mould using pressure.
k, so what is the purpose of the ‘gasket’? as well, how do you go about injecting resin?? how would this work, kinda like a feed gun? is a special RTM resin used?
the gasket, I assume is to make up for the thickness of the material, that way you can easily produce a male-female pair without having to machine, or take into account material thickness.
The purpose of the gasket is to prevent resin (which is injected into the mould under pressure), from leaking between joining flange of the 2 part mould.