Injection Transfer Moulding – An Innovative Basis for
the Processing of Thermoplastic Materials
Institut für Kunststoffverarbeitung in Industrie und Handwerk an derRheinisch-Westfälischen Technischen Hochschule Aachen (IKV)
URL: www.ikv-aachen.de
e-mail:
koch@ikv.rwth-aachen.de
Abstract
Injection-Transfer-Moulding
(ITM) is a combination of the well-known injection moulding and transfer
moulding processes where the melt is not directly injected into the cavity in
contrast to conventional injection moulding. Instead, the melt dosed in the
aggregate is led over to a so called transfer chamber. In a second process step
this melt is transferred into the melt cavities of the closed mould by a
piston- and cylinder-system.
In
comparison to the conventional injection moulding, Injection-Transfer-Moulding
provides many advantages for both the quality of the part and the flexibility
of the manufacturing process. A vital advantage regarding the quality of the
part is the low injection pressure necessary to fill the cavity, because of the
short gate design. Due to this, it is possible to produce parts with low inner
stress, leading to reduced shrinkage and warpage typical for the processing of
macromolecular moulding compounds. Furthermore, in many cases the expensive and
widely ramified gate system can be reduced, which means less waste and lower
costs for secondary finishing.
Although
these stated advantages are to be generally expected for all plastics, ITM has
only been used for the processing of cross-linking plastics so far. Researches
at the Institute for Plastics Processing (IKV) made the ITM-Process accessible
for the processing of thermoplastic materials by use of a newly developed
mould. It was possible to produce high quality parts form different cavities
within one cycle.