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Effect of thermal ratcheting on the mechanical properties of Teflon and fiber based gasket materials
Author(s) -
Kanthabhabha Jeya Rahul Palaniappan,
Bouzid AbdelHakim
Publication year - 2019
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.47265
Subject(s) - creep , materials science , composite material , gasket , polytetrafluoroethylene , thermal expansion , modulus , thermal , thermodynamics , physics
This paper discusses the effect of thermal ratcheting on the material properties of expand polytetrafluoroethylene (ePTFE), virgin polytetrafluoroethylene (vPTFE), and compressed nonasbestos fiber (CNA) gasket materials. Comparison between the creep strain at constant temperature and when subjected to thermal ratcheting show a 7.7 and 28% increase in the creep strain of ePTFE and vPTFE, respectively. In addition, thermal ratcheting produces a substantial reduction of creep modulus of these materials. The CNA material does not exhibit significant change in creep strain or in creep modulus with thermal ratcheting. However, all three gasket materials show a momentous raise in the creep strain when the material temperature is reduced. On declining the gasket temperature from 212 to 100 °F at the end of 20th thermal cycle, the materials—ePTFE, vPTFE, and CNA exhibit 27, 48, and 15% increase in creep strain value, respectively. The percentage of thickness reduction raises with the increase of cyclic temperature and with increase of creep pre‐exposure time, except for CNA where only a small variation is observed. The coefficient of thermal expansion of both PTFE materials shows a significant change due to cyclic temperature and initial creep exposure. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47265.