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A special mold and tracer technique for studying shear and extensional flows in a mold cavity during injection molding
Author(s) -
Schmidt L. R.
Publication year - 1974
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760141111
Subject(s) - mold , materials science , extensional definition , molding (decorative) , rheometer , shear (geology) , capillary action , deformation (meteorology) , flow (mathematics) , composite material , tracer , engineering drawing , mechanics , geology , rheology , engineering , paleontology , physics , nuclear physics , tectonics
A specially‐designed mold with interchangeable cavity plates was built and used with an Instron capillary rheometer, type MCR, to investigate the injection molding process. Flow patterns in the mold cavity were illustrated with a visual tracer technique. The complete deformation history of the tracers was recorded on a motion picture for several runs. The flow patterns provide data for computing the components of the rate‐of‐deformation tensor which is used to identify specific shear and extensional flows. The tracer marks in the cross section of a molding offer information on the skin thickness and the dimensions of the core channel.