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The effects of multiple impacts on the cushioning properties of closed‐cell foams
Author(s) -
Totten Troy L.,
Burgess Gary J.,
Singh S. Paul
Publication year - 1990
Publication title -
packaging technology and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.365
H-Index - 50
eISSN - 1099-1522
pISSN - 0894-3214
DOI - 10.1002/pts.2770030208
Subject(s) - cushioning , cushion , materials science , shock (circulatory) , deformation (meteorology) , structural engineering , composite material , cell structure , engineering , medicine , biological system , biology
Manufacturers of closed‐cell cushioning materials traditionally publish cushion curves for a given material only for a limited number of impacts. The goal of this research was to describe the change in the cell structure of a close‐cell foam due to multiple impacts, and to extend the range of application of these cushion curves as they relate to reusable packaging. Cushion curves and stress‐strain curves for up to 15 compressions were generated for three different molded closed‐cell foams. The cushion curves demonstrate a constant increase in the shock transmitted with each impact due to significant permanent deformation in the form of cell‐wall fatigue and rupture. The results also show that although the mean percentage increase in transmitted shock was greatest from the first impact to the fifth impact, the change continued to be significant with subsequent impacts.