VALUATION OF SUGAR BEET PULP FIBROUS RESIDUES IN PAPER

Fibrous residues from acidic and enzymatic hydrolysis of sugar beet pulp can be applied to increase bonding potential and partial replacement of recovered fibres. The authors investigated the influence of original, chemically and enzymatically modified sugar beet pulp on fibre suspension and laboratory handsheets properties from recovered fibres. With increasing content of sugar beet pulp in a mixture with recovered fibres, drainage time, water retention value, tensile index, burst index and internal bond strength increased, bending resistance and porosity decreased. The effect of sugar beet pulp on fibre suspension and laboratory handsheets properties increased in the sequence original, chemically and enzymatically modified sugar beet pulp. Optimum input of original sugar beet pulp is 15-20 %, of chemically modified sugar beet pulp 10-15 % and of enzymatically modified sugar beet pulp 5-10 %. The retention and drainage system improved drainage, reduced COD and BOD5 of filtrates from a mixture of recovered fibres with addition of original, chemically and enzymatically modified sugar beet pulp and increased internal bond strength of laboratory handsheets. By applying a retention and drainage system, it is possible to increase optimal input of original, chemically and enzymatically modified sugar beet pulp in it mixture with recovered fibres approximately by 5 %.