Fractionation of wheat straw pulp in ultra-fine pressure screening

摘要

Wheat straw is used as a raw material in paper products, but some cell types of heterogeneous wheat straw pulp are detrimental to pulp processability and end use properties. The aim of this study was to discover the fractionation tendencies of various cell types in an ultra-fine pressure screening. A cell-type categorization based on an automatic optical fibre analysis was used in the fractionation analysis. The shortest epidermal and parenchyma cells and short fibrous cells were concentrated into the fraction passing the screen, whereas long fibrous cells and long wide vessel elements and parenchyma cells were retained preferentially in the fraction remaining on the screen. The results also show that the passage ratio is an important parameter in predicting the fractionation tendency of wheat straw pulp cells in such ultra-fine pressure screening. It was shown that ultra-fine pressure screening is a useful tool in producing fractions with divergent cell types and cell properties.