Soda-AQ pulping of four acacias from Sudan

Four pontential Acacias (Acacia mellifera, A. senegal, A. seyal var fistula and var seyal) grown in Sudan were examined for their suitability for pulping and papermaking. Their physical, morphological and chemical characteristics, and fibre dimensions are reported. The pulping trials with both soda and soda-anthraquinone (aoda-AQ) methods were carried out. The soda-AQ pulping for all species studied to the same kappa number showed increased yield and gave pulps with properties superior to those of soda pulping for tear resistance. The use of wet-end/dry-strength additive (0.5% guar gum on oven-dry wood) during beating improved the mechanical properties and made the pulping of the species more attractive. All species studied gave, with a mild HE/PHP bleaching sequences, bleached pulps suitable for use in writing and printing grades of paper.