Casting ABS?

[Neil WyattModerator @neilwyatt]

I just noticed that my jar of 'ABS Juice' made by dissolving abs in acetone has dried out.

In the bottom was a perfect cast of the jar in ABS about 40mm diameter by 1mm thick.

Clearly it would be a very slow process, but it might be feasible to cast rather nice little ABS parts using silicone moulds.

[Neil WyattModerator @neilwyatt]

[NigeParticipant @nige81730]

I wonder if curing could be speeded up by applying some vacuum to a vessel containing the casting? Catching and condensing the acetone might not be too problematic.

[Russell EberhardtParticipant @russelleberhardt48058]

I suspect that shrinkage as it dries out would be a problem. ABS melts at 280 C, perhaps you could cast it in a domestic oven?? Failing that how about making a Gingery injection moulding attachment for a pillar drill?

Russell

[Neil WyattModerator @neilwyatt]

My thought is to avoid all the faff of injection moulding.

Shrinkage would appear to be about 7% looking at my accidental experiment.

[Russell EberhardtParticipant @russelleberhardt48058]

Worth a try. Perhaps using just enough acetone to make it flow easily? Too much solvent might cause the three polymers that make up ABS to separate out and result in poorer mechanical properties.

Russell

[DalboyParticipant @dalboy]

Like most thing when you have added the acetone to the abs is that you would need to make a mould very similar to casting metal so that you can overfill as when the acetone evaporates as this is part of the volume of the mix. Also something worth thinking about is the mould material will the acetone attack it so some research into that is needed

This part is more for information rather than what should be used for ABS plastics. I have cast polyester resins to make pens in the past an example in the picture below.

As for the use of a vacuum vessel this will remove the air and would need to be left under vacuum until everything it cured. if the material being put into a chamber is fast setting for example this could cause air bubbles to be suspended in the mix if fast setting materials are used a pressure put would be a better option as this will reduce bubble size

Edited By Derek Lane 2 on 13/08/2018 09:04:39

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