Alkaline peroxide treatment of ECF bleached softwood kraft pulps: Part 2. Effect of increased fiber charge on refining, wet-end application, and hornification
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Zheng Dang
Abstract
The effect of increased fiber charge on refining, cationic starch adsorption, and hornification was examined. Two pulps were investigated: (1) a softwood (SW) kraft pulp (KP) which was bleached elementally chlorine-free (ECF) and served as control; and (2) a control pulp treated with alkaline peroxide, which had a higher fiber charge. It was shown that increased fiber charge can improve the efficiency of the refining treatment, as indicated by differences in tensile index refined from 0 to 1000 revolutions. When the control pulp was refined from 4000 to 8000 revolutions, the tensile index decreased. In contrast, the tensile index of the higher fiber charge pulp (HCP) was higher under the same refining conditions. Upon addition of 2% cationic starch to both pulps, the tensile index of the control pulp increased by 13.7% and that of HCP by 23.7%. Atomic force microscopy did not reveal differences in the surface morphology of the two pulps with and without cationic starch adsorption. Peroxide treatment enhanced the fiber charge of the never-dried pulp. This was beneficial in reducing hornification when pulp was dried at 105°C. However, if the once dried pulp at 105°C was treated with peroxide, this resulted in a drastic decrease in intrinsic viscosity of the pulp and lower tensile and burst indices of the test sheets.
©2007 by Walter de Gruyter Berlin New York
Artikel in diesem Heft
- Meetings
- Micromechanical modeling of solid-type and plate-type deformation patterns within softwood materials. A review and an improved approach
- Failure mechanisms in wood-based materials: A review of discrete, continuum, and hybrid finite-element representations
- Morphological lattice models for the simulation of softwood failure and fracture
- Experimental and numerical investigation of wood fracture mechanisms at different humidity levels
- Material point method simulations of transverse fracture in wood with realistic morphologies
- Simulation of cracks in wood using a coupled material model for interface elements
- Preliminary tests to evaluate the mechanical properties of young trees with small diameter
- Characterization and strength modeling of parallel-strand lumber
- Dynamic behaviour of cork and cork-filled aluminium tubes: Numerical simulation and innovative applications
- A numerical study of the transverse modulus of wood as a function of grain orientation and properties
- Effects of ring characteristics on the compressive strength and dynamic modulus of elasticity of seven softwood species
- Experimental device for the accurate determination of wood-water relations on micro-samples
- Evaluating the suitability of hybrid poplar clones for the manufacture of oriented strand boards
- Finely milled kenaf core as a natural plywood binder
- Alkaline peroxide treatment of ECF bleached softwood kraft pulps. Part 1. Characterizing the effect of alkaline peroxide treatment on carboxyl groups of fibers
- Alkaline peroxide treatment of ECF bleached softwood kraft pulps: Part 2. Effect of increased fiber charge on refining, wet-end application, and hornification
- Molar mass determination of lignins by size-exclusion chromatography: towards standardisation of the method
Artikel in diesem Heft
- Meetings
- Micromechanical modeling of solid-type and plate-type deformation patterns within softwood materials. A review and an improved approach
- Failure mechanisms in wood-based materials: A review of discrete, continuum, and hybrid finite-element representations
- Morphological lattice models for the simulation of softwood failure and fracture
- Experimental and numerical investigation of wood fracture mechanisms at different humidity levels
- Material point method simulations of transverse fracture in wood with realistic morphologies
- Simulation of cracks in wood using a coupled material model for interface elements
- Preliminary tests to evaluate the mechanical properties of young trees with small diameter
- Characterization and strength modeling of parallel-strand lumber
- Dynamic behaviour of cork and cork-filled aluminium tubes: Numerical simulation and innovative applications
- A numerical study of the transverse modulus of wood as a function of grain orientation and properties
- Effects of ring characteristics on the compressive strength and dynamic modulus of elasticity of seven softwood species
- Experimental device for the accurate determination of wood-water relations on micro-samples
- Evaluating the suitability of hybrid poplar clones for the manufacture of oriented strand boards
- Finely milled kenaf core as a natural plywood binder
- Alkaline peroxide treatment of ECF bleached softwood kraft pulps. Part 1. Characterizing the effect of alkaline peroxide treatment on carboxyl groups of fibers
- Alkaline peroxide treatment of ECF bleached softwood kraft pulps: Part 2. Effect of increased fiber charge on refining, wet-end application, and hornification
- Molar mass determination of lignins by size-exclusion chromatography: towards standardisation of the method
