I’ve recently completed a project for university where we were tasked with designing a condom carrier and thought it would be the perfect excuse to play with plastic!
During the process I discovered some things that may come in rather useful when compression moulding with plastic:
-= Wood can be a viable material to create the male part of the mould (provided it’s very smooth)
-= You can greatly improve the cycle time of a compressed part by cooling the metal.
-= …and as long as you’ve got an oven, making small parts is way easier than you would ever think!
The pictures below show my mould and the way in which I was able to cool the mould for much faster cycle times… I created the female part of the mould with sheet metal, which was the only part that I actually heated. The rest of the mould consisted of a wooden jig (to ensure an even wall thickness), a removable base (exposed the underside of metal and allowed for easy removal of part) and then the male part which was made with MDF.
This is the making of the first mould. The nuts serve as a spacer to ensure the male part does not make contact with the female part…
NOTE: I thought I would need to seal the wood so I used a Polyurethane floor coat as I heard it had a very high melting temp… I was wrong…
I’m still in the process of making the shredder… all parts are cut and assembled I’m just finding the right motor.
No, I didn’t get the plastic pre-cut… All I did was take some shears and spent some time cutting it all up by hand ^^
Did you already make the shredder? or did you get the plastic somehow pre-shredded?
Would be interested in speaking more if you have some time to shoot me an email at fei.charleen[at]gmail.com , I am looking for other people in South Africa (prefer Capetown but anywhere SA is cool too!) who have already built/worked with these machines.
This is how I was able to cool the metal so that I could make more parts much faster.
The plastic packet was kept in the fridge while waiting for the plastic to heat.
I removed the hot mould from the oven, compressed the two parts together and let sit for a little while… after which I then removed the base and placed the plastic packet over the metal part.
The water within the plastic packet will ensure that the packet does not melt…
