Untersuchungen zur Abformung geometrischer und stochastischer Strukturen an Spritzgießformteilen

Translated title of the contribution: Replication of geometric and stochastic surface microstructures by injection molding

Gerald Berger

Research output: ThesisDoctoral Thesis

Abstract

The surface quality of injection molded parts is still increasing in importance. It depends on processing conditions of injection molding, the cavity surface structure, the runner system, the used polymer and the part geometry. Differences in structure replication of the cavity surface to the molded part are often leading to differences in surface quality. The systematic analysis of these influence parameters includes series of experiments to texture the plastic mold steel Böhler M333. Furthermore, screening experiments to determine the most important process influence parameters on structure replication were made. A qualitative description of the replication process was built, including the thickness of the frozen layer in the injection phase as an influence parameter. The analyzed dependencies of the structure replication were proved by additional injection molding experiments with replication of different geometric surface micro structures (structure depth of 0.042 mm or 0.1 mm and width in between 0.4 mm and 2 mm) in polypropylene and polycarbonate. By using a thin TiN coating on the cavity surface, the mold temperature can be reduced without any significant change in volumetric structure replication ratio. If the same values of mold-specific parameters are set, the found results can be transferred to other injection molding machines. The RMS roughness is a suitable replication ratio parameter for mirror-finished or brush-polished stochastic cavity surface structures.
Translated title of the contributionReplication of geometric and stochastic surface microstructures by injection molding
Original languageGerman
QualificationDr.mont.
Supervisors/Advisors
  • Mitterer, Christian, Assessor B (internal)
  • Langecker, Günter R., Assessor A (internal)
Publication statusPublished - 2006

Bibliographical note

embargoed until null

Keywords

  • injection molding surface replication surface appearance microstructures
  • geometric microstructures
  • stochastic

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