Geometric Variation in Injection Molding

S. Lorin, Master thesis, Chalmers, supervisor F. Edelvik and J. S. Carlson, examiner I. Rychlik, June 2009.


In every manufacturing process there are variations from nominal values that come from part and assembly variation. A substantial amount of all quality problems come from design concepts, therefore it is important to be able to simulate production variation already in the design phase. Part variation is investigated for plastic parts manufactured in the injection molding process. A regression model is built and fitted using orthogonalexperimental design. The contribution of process parameters melt temperature and packing time are the most influential.

The work presented in this thesis was carried out at Fraunhofer-Chalmers Center, FCC, as a part of the of the ProViking II project Variation Simulation of Light Weight Assemblies funded by the Swedish Foundation for Strategic Research (SSF).

Photo credits: Nic McPhee