The basic mechanism for the development of an irreversible swelling hindrance is discussed. It is demonstrated that changes in cell wall structure caused by pulping, chemical modification and straining during drying influence the ability of fibres to reswell after drying.
The results indicate that structural alterations take place during the drying of a cell wall. It is suggested that the basic phenomenon is the irreversible closing of cell wall pores. This essentially leaves a fibre wall which is more resistant to the mechanical treatment which promotes swelling and more prone to fragmentisation and the production of fines.