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Distortion of nylon 6,6 moldings caused by asymmetric water absorption
Author(s) -
Paterson M. W. A.,
White J. R.
Publication year - 1993
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.760332206
Subject(s) - materials science , composite material , distortion (music) , swelling , crystallization , absorption (acoustics) , modulus , absorption of water , nylon 6 , residual stress , stress (linguistics) , chemical engineering , polymer , amplifier , linguistics , philosophy , optoelectronics , cmos , engineering
Distortion of nylon 6,6 molded bars caused by one‐sided absorption of water has been investigated experimentally and the results have been compared with the predictions of an analysis based on data measured on dry bars or bars that were immersed completely in water. Account is taken of swelling, secondary crystallization, variations in Young's modulus, and the original residual stress distribution prior to the absorption of water. The major influences on distortion are (i) swelling and (ii) secondary crystallization. A much smaller effect is caused by the change in the residual stress distribution resulting from the change in the distribution of Young's modulus that develops when water is absorbed. The two major effects normally act in opposite directions, and may sometimes balance out. Differences in distortion obtained when moldings that had different aging histories were exposed to water absorption from one surface only are discussed.