Basically, the sequences of the ICM process
variants are similar and easy to understand
because all the process involves is an additional
stroke of the clamping unit:
1. Close mould to compression gap.
2. Inject and fi ll cavity 80 – 95 % (equivalent to
100 % or more of the fi nal volume)
3. Sequential or simultaneous compression by
the closing movement of the mould.
4. Post-compression (if required), cooling,
opening, and ejection
Compression is effected either by the closing
movement of the mould only or by the movement
of an individual mould element activated
by a hydraulic core pull function – called core
stamping.
New mould concepts
Mould designs have recently been distinctly
improved. The classic vertical fl ash face is increasingly
being replaced by stamping-frame
concepts or by designs of guided intermediate
plates. In some cases, coining and stamping
variants of ICM have established themselves.
Compression and intermediate opening
Aside from the basic functions, it is possible to
use some additional options in injection compression
moulding, for instance, pre-compression
and intermediate opening. Pre-compression
serves to form the decorating materials. Intermediate
opening may be necessary where the
mould is initially closed somewhat more than
necessary for ICM in order to prevent jetting
and ensure laminar fl ow during injection. Intermediate
opening may also be helpful in foaming
in order to permit expansion of the melt.
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