MICRO MODEL OF PAPER .1. BOUNDS ON ELASTIC PROPERTIES

A micro-model of paper with the cell wall taken as a composite with co ntinuous cellulose microfibrils embedded in a matrix of hemicellulose and lignin is presented. Part 1 presents the derivations for the upper and lower bounds on the elastic and shear moduli and the moisture exp ansion coefficients of assemblages of cell-wall elements. The upper an d lower bounds are established by considering the two extreme configur ations of the cell-wall elements-the series and parallel arrangements. The anisotropy is accounted for by a distribution function for the or ientations of microfibrils.