This paper discusses the effect of the species and property of pulp, the moisture content of paper and relative humidity,adding filler,the density of paper and pressing and drying on the hygroexpansive strain of paper.

Many innovation of the paper machines including stratified headbox, gap former and hybrid former,new technology for pressing and drying parts, new sizepress equipment which can be used for surface sizing, precoating or low weight coating and soft calendering are introduceed in thi.

Many innovation of the paper machines including stratified headbox,gap former and hybrid former,new technology for pressing and drying parts,new sizepress equipment which can be used for surface sizing,precoating or low weight coating and soft calendering are introduceed in this pa.