Effects of Delignifying Treatments on Mechano-sorptive Creep of Wood I. : Instantaneous and total compliance of radial specimens

Abstract

As an additional step to explain the mechanism of mechano-sorptive （ MS ） creep, radial specimens of hinoki （ Chamaecyparis obtuse Endl. ） were subjected to different levels of delignifi cation, and the effect of delignifi cation on MS creep was investigated. In a previous paper, instantaneous and total creep compliance during fi ve moisture cycles under three loading conditions was discussed. In this study, recovery of set of radial specimens described in the previous paper was investigated, and we also compared the results with recovery of set when subjected to a single adsorption or desorption process. The levels of delignifi cation were three: weak （ W ） , moderate （ M ） , and strong （ S ） as described in the previous paper. Untreated specimens （ C ） were also prepared as controls. The loading conditions during moisture cycling were three : “Ad” cycle, “Da ” cycle, and “AD” cycle under continuous load. For specimens subjected to a single adsorption or desorption process under load, “A” -process specimens were under load during adsorption, and “D”-process specimens were under load during desorption. The range of adsorption or desorption was between 40% to 94%RH. The concentrated bending load was set at midspan of specimens, and defl ections were measured at midspan. For the prepared specimens, recovery of set was obtained during adsorption.