Changes Suffered by Fibres in Wheat Straw Pulp Recycling

摘要

Morphological changes suffered by recycled wheat straw pulps were studied with a scanning electronic microscope. The fibers were found to have curled during recycling. The S_1 layer and the S_2 layer of the fibre were separated and the outside layer of the fibre was removed. Fissures or cracks and delaminations appeared in the radial direction of the fibre wall. The shrinkage of the fibre cavity was observed.With the changes of structure, the fibre strength and the fibre bonding capacity decreased during recycling. Fibre length and distribution did not suffer much changes. The crystallinity of cellulose was found to have increased slightly during recycling. It led to a decrease in the ability of fibre swelling.Softwood pulp was also experimented for comparison purposes. It showed that wheat straw pulp fibre did not behave any worse than wood fibre during recycling.