Printing a mould
I would like to print a mould to create a small series of a very simple part without overhangs. Preferably I want to use it to cast resin-objects.
Is it possible to directly print a mould that is durable enough for a small series of resin casts? Maybe by using a heat-resistant resin like 3DM-HTR resin?
Does anybody have any expierience or knowledge on this and can give me some tips what to try?
RE: Printing a mould
Hi I don't know if this will be useful given the time since you posted and the slight difference in my use, but yes I believe printing moulds for casting is very possible.
I work in the R&D departent of a company and we encapsulate circuit boards in plastic to shape them an add enviromental protection. To do this we hold the circuit board in an aluminium mould and inject the plastic at around 80psi 200 degress C.
To speed up the prototyping prcess we started to use 3D printed moulds prior to getting aluminium moulds made. After a lot of experimenting (I wont't go into in this post) we've ended up using Phrozen flex as it prints well, can take the pressure, temperature and is durable to repeated handling and use.
I don't know much about resin casting but if you don't have pressure or temperature most general resins should serfice. The other thing I don't know is adhesion of the casting resin to the cured mould.
If you have any sucess it'd be great if you can post your results.
A bit slow, but I get there in the end.
Your main difficulty will be the texture of the printed layers makes a grippy surface and extracting your product may be difficult. Finishing the mould surfaces mechanically and applying a layer of seperator might help. Consider printing a rough, hard mould with a thin, fine detail, flex liner to aid extraction.
How much heat does your resin generate?
I have successfuly cast lead in a two stage process where the printed master mould, finished as above, was used to cast intermediate, sacrificial plaster moulds into which the melt was poured. The master mould is shaped to produce the whole intermediate mould from a single pour, the master part *and* the mould structure are incorporated. In this example a strong mould case is also needed to prevent the heavy melt forcing the mould apart.
Cheerio,
RE:
Hi,
Together with some companies in Norway, we have experience in 3D printing moulds for injection moulding (of thermoplastics), via the projects "Addform" and "Rapid Tooling 4.0".
We have mostly used other printers than the SL1/SL1S, but with this printer we have successfully printed smaller mould parts with the resins Liqcreate Strong-X and Loctite 3D 3860. There are many resins available now which are suitable for moulds (for injection moulding or other moulding processes). Basically there are two (resin) material properties that are important: 1) Temperature resistance and 2) stiffness/strength/toughness balance. In principle you want to have a mould with high stiffness and strength. There are some resin materials which are very stiff (e.g. with 60 wt% glass powder), but unfortunately these are often brittle, and prone to damage during moulding or when preparing the mould (some machining etc). High tensile strength is needed for some mould features, in particular "cores" that may break off during demoulding. Liqcreate Strong-X is very strong, and it has adequate stiffness and temperature resistance. By the way, the company Liqcreate also has the stiff material Composite-X which we haven't tried (we have used similar materials like Somos PerFORM in other printers.)
Finally it can be mentioned that applying a non-stick coating to the printed mould can improve the demoulding performance, so that the mould can survive longer (more shots). Adequate cooling between the moulding cycles is also important. We use pressurised air, and we have also implemented this in fully automated injection moulding.
-Erik