The Effect of Galacto-Mannans on Handsheets Made From Softwood, Hardwood or Rag Pulps

Some published information reports that galacto-mannans, when used as strength producing beater additives, do not effect significant strength increases in hardwood pulps. In order to investigate this problem further, six pulps covering a wide range of pulping processes and chemical compositions, were evaluated before and after the addition of locust bean gum, a galacto-mannan, to the pulp. The results obtained indicate that galacto-mannans do favorably affect the strength properties of hardwood pulps. Substantial increases in bursting strength, tensile strength and folding endurance were noted for all the hardwood pulps employed, as well as for a rag pulp. These strength increases were caused by very low concentrations of locust bean gum, making their use economically feasible