Differences and similarities between kraft and oxygen delignification of softwood fibers: effects on mechanical properties

Abstract Charged groups in pulp have been shown to enhance the tensile strength of paper produced from pulp. Oxygen delignification introduces charged and it is interest determine how should be distributed between cooking oxygen stage with respect mechanical properties. A number unbleached kraft cooked delignified pulps within a wide kappa range were refined, effects refining on morphology properties studied. The WRV correlated fiber charge at given charge, had same development refining, although they significantly different numbers. during depends rigidity which affected by lignin content, chemical processes used. Refining increased curl decreased pulps, irrespective number. greater increase was seen for higher WRV, probably because degree fibrillation achieved beating process. Despite deformation can larger amount swelling fibers. Graphic abstract