Influences of Bleached Softwood Pulp Pretreated with Endo-Cellulase on Fiber Surface Properties and Aggregation Structure

2011 ◽  
Vol 391-392 ◽  
pp. 692-696
Author(s):  
Min Du ◽  
Xin Ping Li ◽  
Wu Guang Li
Keyword(s):  
Energy Consumption ◽  
Fiber Surface ◽  
Paper Sheet ◽  
Paper Properties ◽  
Enzymatic Pretreatment ◽  
Wetting Properties ◽  
Tear Index ◽  
Softwood Pulp ◽  
Aggregation Structure ◽  
Refining Performance

The influences of endo-cellulase pretreatment of bleached softwood pulp before refining was investigated in this paper. Refining energy consumption, paper properties, wetting properties, electric charge and aggregation structure of fiber were investigated. The results showed that pretreated with endo-cellulase at the dosage of 0.4ECG/g before refining could increase the refining degree by 53.09%, and it would reduce refining energy consumption significantly. At this dosage, the tensile index of the paper sheet increased while the tear index of paper sheet decreased slightly. Additionally, enzymatic pretreatment could raise fiber surface wettability, lower the absolute value of Zeta potential and decrease the crystallinity of fiber, which was help to improve refining performance.

Treatment of NBKP with Cellulase to Reduce the Refining Energy Consumption in Production of Grease Proof Paper

2011 ◽  
Vol 236-238 ◽  
pp. 1379-1384
Author(s):  
Jun Liu ◽  
Hui Ren Hu
Keyword(s):  
Energy Consumption ◽  
Energy Requirement ◽  
Fiber Surface ◽  
Orthogonal Test ◽  
Manufacturing Cost ◽  
Fiber Morphology ◽  
Paper Properties ◽  
Binding Domains ◽  
Tear Index ◽  
Cellulose Binding

Refining is an energy-intensive papermaking process where energy consumption contributes about 18% of the total manufacturing cost. Through the application of cellulases before refining, mills can reduce their energy requirement for refining of pulps and realize the aim of energy consumption. In the present study, two kinds of cellulase within or wothout the cellulose binding domains (CBDs) were used to treat the pulp aimed at reducing the refining energy consumption in production of grease proof paper. In order to compare and evaluate these effects on reducing the pulp refining energy consumption, these two cellulases were compared based on their effects on Schopper-Riegler freeness (°SR), fiber morphology and paper properties ( tensile index, tear index). Orthogonal test was used to examine the interaction of enzyme dosages and contact time on the beatability of the pulp. Results showed that the cellulase of Refinase M (within the CBDs) was excellent in reducing the refining energy consumption, when pretreated with 0.02% of Refinase M about 18.5% of the refining energy can be saved, and the properties of paper were not affected obviously. Moreover, results showed that the existence of CBDs in cellulases play a significant role in reducing the energy consumption. Examination of the fiber surface by SEM show notable improvement in fibrillation.

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.

Using cationic polyvinyl alcohol (C-PVA) to improve the strength of wood-free papers containing high-yield pulp (HYP)

Holzforschung ◽  
2010 ◽  
Vol 64 (5) ◽  
Author(s):  
Xin Liu ◽  
Pedram Fatehi ◽  
Yonghao Ni ◽  
Huining Xiao
Keyword(s):  
Polyvinyl Alcohol ◽  
Apparent Density ◽  
Fiber Surface ◽  
Strength Properties ◽  
High Yield ◽  
Kraft Pulps ◽  
Paper Properties ◽  
Atomic Force ◽  
Tear Index ◽  
Afm Analysis

AbstractHigh-yield pulp (HYP) is gaining increasing interest in wood-free papers, because it can improve the bulk, formation, and opacity of papers. However, one of the challenges for the papermakers is the strength of papers when a large amount of HYP is replaced with hardwood kraft pulp. In this work, we explored the potential of using cationic-modified polyvinyl alcohol (C-PVA) in increasing the strength properties of HYP. Also, C-PVA was applied to the paper-sheets made of softwood/hardwood bleached kraft pulps (SBKP/HBKP) and HYP under various conditions, and the corresponding paper properties were evaluated. It was observed that C-PVA increased the strength properties of these paper-sheets, and the results obtained from using C-PVA were only slightly less effective than those obtained from using cationic starch (C-starch). Furthermore, the addition of C-PVA to HYP, and subsequently mixing with the blend of SBKP/HBKP (option no. 1) improved the tensile and burst indices, light scattering coefficient and apparent density of paper-sheets more significantly than did the addition of C-PVA directly to the mixed furnish of SBKP/HBKP/HYP (option no. 2). Additionally, atomic force microscope (AFM) analysis showed that the attraction force, developed between the AFM-tip and the fiber surface, was changed by the C-PVA modification. The tensile and burst indices of paper-sheets were improved by adding 10 mg g-1C-PVA and substituting 30% of HYP for HBKP, whereas the tear index, apparent density, PPS-roughness, and brightness decreased.

Does kraft hardwood and softwood pulp viscosity correlate to paper properties?

TAPPI Journal ◽  
2016 ◽  
Vol 15 (10) ◽  
pp. 643-651 ◽  
Author(s):  
ROBERT J. OGLESBY ◽  
HUMPHREY J. MOYNIHAN ◽  
RICARDO B. SANTOS ◽  
ASHOK GHOSH ◽  
PETER W. HART
Keyword(s):  
Physical Properties ◽  
Strength Loss ◽  
Strength Properties ◽  
Clear Correlation ◽  
Paper Properties ◽  
Physical Strength ◽  
Pulp Viscosity ◽  
Softwood Pulp ◽  
The Impact ◽  
Related Paper

The impact of commercially prepared, fully bleached pulp viscosity variation on handsheet physical properties was evaluated at different levels of pulp refining. Hardwood pulps from the same brownstock species mix, cooking parameters, and kappa numbers were processed through two different commercial bleach plants: one with a D0(EP)D1D2 sequence and the second with an OD0(EOP)D1 sequence. Additionally, a commercial softwood (predominately Scotts pine) brownstock pulp bleached by an OD0(EP)D1D2 sequence was employed in this study. Pulps with viscosities ranging from 14 to 21 mPa∙s were refined in a Valley beater to two freeness levels, and the associated handsheet physical properties were measured in this study. Over the pulp viscosity range of 14 to 21 mPa∙s, no clear correlation was found to exist between pulp viscosity and related paper physical properties. Finally, a series of laboratory prepared bleached pulps were purposely prepared under non-ideal conditions to reduce their final viscosities to lower values. Handsheets made from these pulps were tested in their unbeaten condition for physical strength properties. Significant and rapid strength loss occurred when the measured pulp viscosity dropped below 12 mPa∙s; overall strength properties showed no correlation to viscosity above the critical 12 mPa∙s value.

From biorefineries to bioproducts: conversion of pretreated pulp from biorefining streams to lignocellulose nanofibers

TAPPI Journal ◽  
2019 ◽  
Vol 18 (4) ◽  
pp. 233-241
Author(s):  
CHENGGUI SUN ◽  
RICHARD CHANDRA ◽  
YAMAN BOLUK
Keyword(s):  
Energy Consumption ◽  
Enzymatic Hydrolysis ◽  
Rheological Behavior ◽  
Material Basis ◽  
Softwood Pulp ◽  
Energy Consumptions ◽  
Hardwood Pulp ◽  
The Stability ◽  
Lignocellulose Nanofibers

This study investigates the use of pretreatment and enzymatic hydrolysis side streams and conversion to lignocellulose nanofibers. We used a steam-exploded and partial enzymatic hydrolyzed hardwood pulp and an organosolv pretreated softwood pulp to prepare lignocellulose nanofibers (LCNF) via microfluidization. The energies applied on fibrillation were estimated to examine the energy consumption levels of LCNF production. The energy consumptions of the fibrillation processes of the hardwood LCNF production and the softwood LCNF production were about 7040-14080 kWh/ton and 4640 kWh/ton on a dry material basis, respectively. The morphology and dimension of developed hardwood and softwood LCNFs and the stability and rheological behavior of their suspensions were investigated and are discussed.

Enzyme-assisted pulp refining: an energy saving approach

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Amit Kumar ◽  
Chhotu Ram ◽  
Adebabay Tazeb
Keyword(s):  
Energy Consumption ◽  
Paper Industry ◽  
Electrical Power ◽  
Manufacturing Cost ◽  
Paper Properties ◽  
Paper Making ◽  
Paper Manufacturing ◽  
Cost Of Energy ◽  
Refining Time ◽  
Electrical Power Consumption

AbstractEnergy conservation has become an essential step in pulp and paper industry due to diminishing fossil reserves and high cost of energy. Refining is a mechanical treatment of pulp that modifies the structure of the fibres in order to achieve desired paper-making properties. However, it consumes considerable amount of energy. The electrical power consumption has a direct impact on paper manufacturing cost. Therefore, there is a requirement to minimize the energy cost. Enzyme-assisted refining is the environment friendly option that reduces the energy consumption for papermaking. Enzyme-assisted refining is defined as mechanical refining after pretreatment of pulp with enzymes such as cellulases and hemicellulases. It not only reduces the energy consumption but also improves the quality of finished paper. Enzymes improve the beatability of pulp at same refining degree (°SR) and desired paper properties can be achieved at decreased refining time. The selection of suitable enzyme, optimization of enzyme dose and appropriate reaction time are the key factors for energy reduction and pulp quality improvement during enzyme-assisted refining.

scholarly journals Effect of compression refining on fiber properties

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8696-8707
Author(s):  
Jari Käyhkö ◽  
Eero Hiltunen ◽  
Yrjö Hiltunen ◽  
Ekaterina Nikolskaya ◽  
Lauri Kulmala ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Energy Consumption ◽  
Magnetic Resonance ◽  
Time Domain ◽  
Strength Properties ◽  
Net Energy ◽  
Fiber Properties ◽  
Nmr Method ◽  
Low Field ◽  
Softwood Pulp

This article shows how fiber properties obtained by the compression refining of bleached softwood pulp refined using a KID 300 refiner differs from traditional bar refining. A KID refiner is a stone crusher that has been modified to refine fiber, and it offers a refining method that could be used at the mill scale. This study showed that compression refining caused more internal fibrillation compared with blade refining and improved the pulp’s ability to be beaten. Net energy consumption in compression refining was less than that of bar refining. Compression refining yielded pulp with shorter fibers and a higher number of fines, kinks, and curves. Still, the strength properties of the paper were the same level as bar-refined pulp, probably due to the higher internal fibrillation and flexibility of the fibers. It was also shown that the low field time-domain nuclear magnetic resonance (TD-NMR) method was capable of measuring the porosity and internal fibrillation of the fiber.

Tear and tensile strength development of PGW and CTMP pulps mixed with PLA or viscose fibres

2014 ◽  
Vol 29 (2) ◽  
pp. 304-308 ◽  
Author(s):  
Jaakko Asikainen ◽  
Antti Korpela
Keyword(s):  
Tensile Strength ◽  
Fibre Length ◽  
Wood Fibre ◽  
Strength Development ◽  
Paper Properties ◽  
Mechanical Pulp ◽  
Tear Strength ◽  
Tear Index ◽  
Simultaneous Decrease ◽  
A Minor

Abstract The objective was to evaluate the effects on paper properties when replacing a minor share of wood fibre by synthetic fibre. The aim was to increase tear strength and stretch while minimizing the loss of tensile strength in paper consisting of mechanical pulp. Tested synthetic fibres included PLA and viscose fibres mixed with mechanical or chemi-mechanical pulp. Even at relatively low proportions, the synthetic fibres contributed to a significant increase of tear strength in the wood fibre based papers. With the highest tested proportion (20%) the increase of tear index in PGW based stock was 243% with PLA and 177% with viscose fibre. However, a simultaneous decrease in tensile strength and tensile stiffness was observed. The stretch at break remained unchanged. Thickness reduction of the synthetic fibres resulted in an increase of tear strength. The effect is due to the high fibre length of synthetic fibres, producing mechanically well entangled networks, coupled with the high enough strength of the synthetic fibres.

scholarly journals Blending impact of hardwood pulps with softwood pulp on tissue paper properties

Wood Research ◽  
2020 ◽  
Vol 65 (3) ◽  
pp. 447-458
Author(s):  
MONIKA STANKOVSKÁ ◽  
MÁRIA FIŠEROVÁ ◽  
JURAJ GIGAC ◽  
ELENA OPÁLENÁ
Keyword(s):  
Paper Properties ◽  
Tissue Paper ◽  
Softwood Pulp

scholarly journals EFFECT OF CHITOSAN ADDITION DURING PAPER-MAKING ON AGEING STABILITY OF DOCUMENT PAPER

2021 ◽  
Vol 55 (9-10) ◽  
pp. 1083-1094
Author(s):  
DIMITRINA TODOROVA ◽  
◽  
VESKA LASHEVA ◽  
Keyword(s):  
Chitosan Solution ◽  
Thermal Ageing ◽  
Paper Strength ◽  
Aluminium Sulphate ◽  
Paper Properties ◽  
Hygroscopic Properties ◽  
Complex Evaluation ◽  
Softwood Pulp ◽  
Negative Effect ◽  
Hardwood Pulp

The aim of the present work has been to study the influence of chitosan addition into the composition of paper intended for documents on its ageing stability, with a view of enhancing the resistance of paper strength and optical properties over time. The chitosan solution was added during the formation of the paper sheets in various amounts: 0.2%, 1% and 2% o.d.f. Paper samples of different fibrous compositions were prepared from bleached sulphate softwood pulp (BSWP) and bleached sulphate hardwood pulp (BHWP) in the following ratios: 50% BSWP:50% BHWP, 80% BSWP:20% BHWP, 100% BSWP and 100% BHWP. Then, paper samples were subjected to accelerated thermal ageing for 24 hours at 105 °C. It was found that the use of chitosan as additive in the composition of bleached cellulose paper samples led to improved strength and hygroscopic properties. The study showed that chitosan could be used in the production of kraft document papers comprising aluminium sulphate, as the presence of aluminium sulphate had no negative effect on the action of the biopolymer. Regarding the complex evaluation of the properties of the obtained papers, it could be summarized that, for the studied fibrous compositions, the optimum amount of the additive was 1% chitosan for a fibrous composition of 50% bleached softwood pulp and 50% bleached hardwood cellulose. Therefore, preparing document paper with the addition of chitosan is a convenient procedure to enhance a number of paper properties, even after the ageing process.

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