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Analysis of stresses arising during the processing of polymeric films on tentering frames
Author(s) -
Jennings Robert M.,
Farris Richard J.
Publication year - 1992
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.760322308
Subject(s) - materials science , anisotropy , transverse isotropy , composite material , transverse plane , isotropy , polyimide , line (geometry) , principal axis theorem , elasticity (physics) , principal stress , shear (geology) , structural engineering , geometry , optics , physics , mathematics , layer (electronics) , engineering
A model based on linear elasticity is presented describing the stresses arising during the processing of polymeric films on tenter frames. The model demonstrates that large in‐plane shear stresses, resulting from gradients in the line, produce anisotropic stresses in the film. The magnitude of the anisotropy is found to vary transversely across the line, becoming isotropic in the center and achieving maximum values at the edges of the line. The principal directions of the stress tend to lie at ±45° to the machine direction but may be altered by machine and transverse drawing by the frame. These results agree with orientation measurements reported in the literature on polyimide films produced on tentering frames.