HOPKINSON, N. and DICKENS, P.M., 2000. A comparison between stereolithography and aluminium injection moulding tooling. Rapid prototyping journal, 6 (4), pp. 253-258
Advances in rapid prototyping and machining have resulted in reduced lead times for
injection moulding tooling. Comparisons between aluminium and stereolithography
(SL) tools are made with regard to the ejection forces required to push mouldings
from the tools, heat transfer through the tools and the surface roughness of the tools.
The results show that ejection forces for both types of tools are increased
when a longer cooling time prior to ejection is used. The ejection forces required
from a rough aluminium tool are considerably higher than those from a smooth
SL tools do not appear to be subjected to any smoothing as a result of
moulding polypropylene parts, this is explained by the fact that the tool’s surface acts
in a rubber like manner during part ejection. The rubber like nature of the tool’s
surface is as a direct consequence of the low glass transition temperature and low
thermal conductivity of the tool material. Further potential benefits of the low
thermal properties of the tool are discussed.