Fundamental understanding of pulp property development under different thermomechanical pulp refining conditions as observed by a new Simons’ staining method and SEM observation of the ultrastructure of fibre surfaces
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Abstract
The morphological and chemical characteristics of cell walls govern the response of wood fibre to mechanical pulping processes and thereby influence the energy efficiency of the process and determine most pulp and paper properties. A study has been carried out at the microstructural/ultrastructural level of fibre cell walls by means of a newly developed Simons’ staining (SS) method and scanning electron microscopy to characterize thermomechanical pulps (TMPs) produced under different refining conditions. The SS method allows assessment and quantification of pulp fibre development during the process in terms of cell wall delamination/internal fibrillation (D/IF) under different process conditions, and the degree of D/IF can be statistically evaluated for different TMP types. In focus was never-dried Norway spruce TMP from primary stage double-disc refining running in a full-scale mill, where specific refining energy was varied at different refining pressure levels. Improved energy efficiency was gained at the same tensile index level when applying high pressure (temperature). Under conditions of high pressure and refining energy, a significant enhancement of the degree of D/IF of pulp fibres was observed. The surface ultrastructure of these fibres exhibited an exposed S2 layer with long ribbon-type fibrillation compared to pulps produced with lower pressure and energy input. A given TMP type can be classified in the categories of high-severity and low-severity changes and quasi-untreated concerning the degree of D/IF of its fibres. The relative proportions of these are important for the development of pulp properties such as tensile strength. The presence of higher amounts of fibre fractions in the categories high D/IF and low D/IF will improve the tensile index of a TMP.
©2011 by Walter de Gruyter Berlin Boston
Articles in the same Issue
- Original Papers
- Fundamental understanding of pulp property development under different thermomechanical pulp refining conditions as observed by a new Simons’ staining method and SEM observation of the ultrastructure of fibre surfaces
- Enhancing dewatering of thermo-mechanical pulp (TMP) based papermaking through enzymatic treatment
- Mechanisms of TMP peroxide bleaching using Mg-based alkalis
- Properties of wood chips for thermomechanical pulp (TMP) production as a function of spout angle
- Determination of local material properties of OSB sample by coupling advanced imaging techniques and morphology-based FEM simulation
- Combined bound water and water vapour diffusion of Norway spruce and European beech in and between the principal anatomical directions
- Oxygen plasma-treated enzymatic hydrolysis lignin as a natural binder for manufacturing biocomposites
- Influence of the adhesive formulation on the mechanical properties and bonding performance of polyurethane prepolymers
- Characterizing perpendicular-to-grain compression (C⊥) behavior in wood construction
- Predicting the strength of Populus spp. clones using artificial neural networks and ε-regression support vector machines (ε-rSVM)
- X-ray scattering and microtomography study on the structural changes of never-dried silver birch, European aspen and hybrid aspen during drying
- Equilibrium moisture content (EMC) in Norway spruce during the first and second desorptions
- Fungal degradation of bamboo samples
- qPCR as a tool to study basidiomycete colonization in wooden field stakes
- Meetings
- Meetings
Articles in the same Issue
- Original Papers
- Fundamental understanding of pulp property development under different thermomechanical pulp refining conditions as observed by a new Simons’ staining method and SEM observation of the ultrastructure of fibre surfaces
- Enhancing dewatering of thermo-mechanical pulp (TMP) based papermaking through enzymatic treatment
- Mechanisms of TMP peroxide bleaching using Mg-based alkalis
- Properties of wood chips for thermomechanical pulp (TMP) production as a function of spout angle
- Determination of local material properties of OSB sample by coupling advanced imaging techniques and morphology-based FEM simulation
- Combined bound water and water vapour diffusion of Norway spruce and European beech in and between the principal anatomical directions
- Oxygen plasma-treated enzymatic hydrolysis lignin as a natural binder for manufacturing biocomposites
- Influence of the adhesive formulation on the mechanical properties and bonding performance of polyurethane prepolymers
- Characterizing perpendicular-to-grain compression (C⊥) behavior in wood construction
- Predicting the strength of Populus spp. clones using artificial neural networks and ε-regression support vector machines (ε-rSVM)
- X-ray scattering and microtomography study on the structural changes of never-dried silver birch, European aspen and hybrid aspen during drying
- Equilibrium moisture content (EMC) in Norway spruce during the first and second desorptions
- Fungal degradation of bamboo samples
- qPCR as a tool to study basidiomycete colonization in wooden field stakes
- Meetings
- Meetings
