Overmoulding a part
Overmoulding a part
(OP)
I have to design an injection mould which moulds over a steel part. This is no problem except for the tolerance of the steel part. It is +.5, -.5. Any ideas how to soak up the tolerance in the tool?






RE: Overmoulding a part
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RE: Overmoulding a part
Is the gap the furthest point from the gate.
Can you tolerate a little flash.
How good will the ring check valve be.
How good will the injection control device be.
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Overmoulding a part
the steel part will be overmoulded in nylon,
no flash allowed
the whole steel part is covered in plastic (top, bot & sides) except for some pads on the top & bot face of the steel part which need to s/o in the tool.
There is a hole up the centre of the part which is not
overmoulded , this is where the feed will be, so steel on the tool needs to stand up & s/o in this hole.
The finished part has a tolerance of +/- 0.1mm (plastic to plastic). This is where the problems are
RE: Overmoulding a part
You will need much tighter tolerances for the steel, or you will need to sort the steel by size and have a number of inserts for the mould so that the gap is never over about 0.05mm.
Another option is to have a hydraulic core that closes against the steel in the critical area and seals off.
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.