Influence of Cellulase to Aggregation Structure of Bleached Softwood Pulp

2012 ◽  
Vol 549 ◽  
pp. 255-259
Author(s):  
Min Du ◽  
Xin Ping Li ◽  
Zhi Min Yao
Keyword(s):  
Water Retention ◽  
Enzymatic Treatment ◽  
Crystalline Region ◽  
Water Retention Value ◽  
Softwood Pulp ◽  
Aggregation Structure ◽  
Enzyme Dosage

Cellulase named as Celluclast 1.5L was used to deal with bleached softwood pulp. By analyzing the changes of water retention value and crystallinity of fiber after enzymatic treatment, studied the influence of cellulase to aggregation structure of bleached softwood pulp. The results show that with the increasing of the enzyme dosage, the proportion of long-fiber decreases and the content of fines increases. Water retention value of pulp first decreases and then increases. The fiber crystal does not change with the enzymatic treatment, but with the increasing of the enzyme dosage, the crystallinity of fiber first increases and then decreases. It indicates that the cellulase would act on the crystalline region of fiber in the higher enzyme dosage.

Recycled fiber treated with NaOH/urea aqueous solution: effects on physical properties of paper sheets and on hornification

2018 ◽  
Vol 33 (4) ◽  
pp. 651-660 ◽  
Author(s):  
Yingju Miao ◽  
Yunfei Zhi ◽  
Heng Zhang ◽  
Ying Chen ◽  
Shaoyun Shan ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Physical Properties ◽  
Water Retention ◽  
Crystalline Region ◽  
Cellulose Film ◽  
Reinforced Concrete Structure ◽  
Water Retention Value ◽  
Fiber Network ◽  
Urea Aqueous Solution ◽  
Intramolecular Hydrogen

Abstract Hydrogen bonding among fiber microfibrils is the primary cause of fiber hornification, wherein NaOH/urea aqueous solution precooled to −13 °C can disassemble inter- and intramolecular hydrogen bonds. Whether hornified fibers treated with this process can significantly improve fiber swelling ability and physical properties of the resulting paper sheets remains a problem. In this investigation, the 6th cycle fiber was pretreated with this procedure, and the water retention value of the fiber before and after treatment and the physical properties of the resulting paper sheets were studied. The results indicate that the lignin decline, complete swelling of flat fiber, filling of cellulose film between the interfiber network, and decreasing crystalline region all contribute to the increase in water retention value. The water retention value of repaired fiber is equivalent to that of virgin pulp, and hornification reverses by 89 %. In addition, the cellulose film filling among the fiber network constructs a similar reinforced concrete structure, which causes the tear, burst, and tensile index of the resulting paper sheets to increase by 145 %, 98 %, and 43 %, respectively.

Modification of Bleached Softwood Pulp with Xylanase

2011 ◽  
Vol 393-395 ◽  
pp. 855-858
Author(s):  
Min Du ◽  
Xin Ping Li ◽  
Wu Guang Li
Keyword(s):  
Zeta Potential ◽  
Fiber Length ◽  
Fiber Surface ◽  
Enzymatic Treatment ◽  
Surface Wettability ◽  
Refining Efficiency ◽  
Tensile Index ◽  
Tear Index ◽  
Softwood Pulp ◽  
Enzyme Dosage

Xylanse named as Pulpzyme HC was used to modify bleached softwood pulp before refining. The efficiency of modification by different enzyme dosage was invested in this paper. The result showed that enzymatic treatment decreased the dissolved charge and absolute Zeta potential of the slurry and increased the fiber surface wettability. Appropriate Pulpzyme HC (0.4u/g) could improve the refining efficiency by 9.5°SR. The brightness and bulk of hand sheets increased with the increasing of the enzyme. Tensile index and tear index of hand sheets reached the maximum at the enzyme dosage of 0.2u/g. In this dosage, fiber length, knot index and curl index of fiber increased. But excessive enzyme decreased the tear index and had no effect on the tensile index.

Influence of Cellulase to Filtration and Fiber Morphology of Bleached Softwood Pulp

2012 ◽  
Vol 550-553 ◽  
pp. 1182-1185
Author(s):  
Min Du ◽  
Xin Ping Li ◽  
Meng Luo
Keyword(s):  
Mode Of Action ◽  
Fiber Length ◽  
Fiber Surface ◽  
Cellulose Hydrolysis ◽  
Enzymatic Treatment ◽  
Polymerization Degree ◽  
Fiber Morphology ◽  
Softwood Pulp ◽  
Before And After ◽  
Enzyme Dosage

Cellulase named as Celluclast 1.5L was used to deal with bleached softwood pulp. By analyzing the changes of fiber polymerization, fiber length and pulp freeness before and after enzymatic treatment, studied the influence of cellulase to filtration and fiber morphology of bleached softwood pulp, and discussed the mode of action of cellulase to bleached softwood pulp. The results show that while the enzyme dosage increasing, the degree of cellulose hydrolysis increases; the pulp polymerization degree decreases; fiber length decreases and the content of fines increase. Pulp filtration first increases and then decreases, but fiber surface does not appear the phenomenon of fibrillating. It indicates that the action of cellulase to fiber is from the inside to outside.

Effects of a PFI refiner’s operational parameters on the swellability of recycled fiber

TAPPI Journal ◽  
2020 ◽  
Vol 19 (5) ◽  
pp. 239-246
Author(s):  
XIAONING SHEN ◽  
BO LI ◽  
WENXUAN MO ◽  
XIN-SHENG CHAI
Keyword(s):  
Water Retention ◽  
Fiber Quality ◽  
Operational Parameters ◽  
Fiber Morphology ◽  
Water Retention Value ◽  
Electron Microscopic ◽  
Mathematical Relation ◽  
Scanning Electron Microscopic ◽  
Recycled Fiber ◽  
Scanning Electron

This paper presents data on the effects of operational parameters (number of revolutions, linear pressure, and gap) of the PFI refiner on the swellability of recycled fiber, which was characterized by water retention value (WRV). The results showed that the increase of recycled fiber’s WRV was proportional to the number of revolutions and the linear pressure, but inversely proportional to the gap. The mathematical relation between these parameters and the fiber WRV could be described by an empirical model for gaps greater than 0.1 mm. Scanning electron microscopic images of fiber morphology showed that the basic framework of fibers could be maintained with the gap greater than 0.1 mm, but was destroyed with smaller gaps. This model provides a technical reference for quantitative control of refining treatment and an effective method for improving recycled fiber quality.

New model for predicting tensile strength and density of eucalyptus handsheets based on an activation parameter calculated from fiber distribution characteristics

Holzforschung ◽  
2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Iiro Pulkkinen ◽  
Juha Fiskari ◽  
Ville Alopaeus
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Wall Thickness ◽  
Water Retention ◽  
Activation Parameter ◽  
Water Retention Value ◽  
Data Set ◽  
Network Activation ◽  
Fiber Wall ◽  
Fiber Segment

Abstract The activation parameter developed is based on the fiber wall thickness distribution, fiber curl distribution, and water retention value of the unrefined fibers. The mechanical properties of paper that contain chemical pulp depend, among other things, on the free fiber segment activation between fiber-fiber crossings that is created during drying. Experimental data revealed that the degree of fiber swelling is responsible together with the fiber shape factor (curl) and fiber wall thickness for the extent of fiber network activation. The amount of bonding between fibers also affects fiber segment activation. Based on the experimental data, it was deduced that interfiber bonding ability of fibers, characterized as the water retention value, was mainly responsible for the development of handsheet density. Tensile index development was more affected by the morphology of fibers, which was the main determinant for high activation potential of fibers. Factor analysis was used to identify the main causes of variation for a refining data set of 20 Eucalyptus grandis samples. Three independent descriptors were found to be responsible for the majority of the variation: the bonding and activation factor, the factor of microcompressions, and the factor of fiber wall thickness and fiber curl. The activation parameter developed in this study can be used to determine the effect of fiber segment activation and inter-fiber bonding on the inplane mechanical properties of paper.

Use of Cellulose-Containing Fillers in Composites with Polypropylene

1970 ◽  
Vol 17 (2) ◽  
pp. 150-154
Author(s):  
Marianna LAKA ◽  
Svetlana CHERNYAVSKAYA ◽  
Galia SHULGA ◽  
Viktor SHAPOVALOV ◽  
Andrej VALENKOV ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Shear Modulus ◽  
Rapeseed Oil ◽  
Water Retention ◽  
Raw Materials ◽  
Water Retention Value ◽  
Water Vapour Sorption ◽  
Recycled Polypropylene ◽  
Sulphate Pulp

The composites, containing recycled polypropylene and fillers, obtained from different lignocellulosics by the thermocatalytic destruction method, were investigated. Birch sawdust, newsprint wastes, cotton residues and wood bleached sulphate pulp were used as raw materials for obtaining fillers. The indices of mechanical properties (tensile strength, modulus of elasticity, deformation at break, shear modulus, toughness, twisting moment) of the composites' samples were determined. It has been found that the obtained composites have relatively good mechanical properties. Better results were obtained, using fillers from sawdust and wood pulp. After treating the fillers with rapeseed oil, their water vapour sorption and water retention value (WRV) decreased. In this case, the strength of the composites was higher.http://dx.doi.org/10.5755/j01.ms.17.2.484

Mercerization and Characterization of Straw Pulp Fibers

2013 ◽  
Vol 781-784 ◽  
pp. 2645-2649
Author(s):  
Yan Na Yin ◽  
Quan Xiao Liu ◽  
Yu Bin Lyu
Keyword(s):  
Cell Wall ◽  
Processing Time ◽  
Water Retention ◽  
Fiber Cell ◽  
Pulp Fibers ◽  
Water Retention Value ◽  
Treatment Conditions ◽  
Fiber Cell Wall

Effects of mercerizing treatment on water-retention value of straw pulp fibers were discussed and the mercerizing treatment conditions were optimized. The best conditions of mercerizing treatment is NaOH concentration of 4mol/L, temperature of 40°C and processing time of 60min. SEM showed that the fiber cell wall swelling increase after mercerization.

Relationship between Viscosity and Recycling of Dendrocalamus giganteus Munro Pulp

2012 ◽  
Vol 518-523 ◽  
pp. 604-607
Author(s):  
Jie He
Keyword(s):  
Low Temperature ◽  
Water Retention ◽  
High Viscosity ◽  
Kraft Pulping ◽  
Water Retention Value ◽  
Dry Heat ◽  
Pulp Viscosity ◽  
Kraft Cooking ◽  
The Relationship ◽  
Dendrocalamus Giganteus

In this paper, two groups of Dendrocalamus giganteus Munro pulp were obtained from conventional kraft pulping (the maximum pulping temperature was 165°C) and low-temperature kraft pulping (the maximum pulping temperature was only 135°C) under the premise of kappa number of about 17, and the viscosity of them were 1240 mL•g-1 and 1426 mL•g-1 respectively. Then the handsheets was treated with dry heat aging and the simulation of pulp recycling was investigated. In addition, the relationship between the pulp viscosity and recycling times of pulp were studied. The results showed that the viscosity and water retention value of two groups of pulp decreased with increasing of recycling times. However, the recycling characteristic of the pulp with high viscosity from low-temperature kraft cooking was better.

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