Research on Biological and Mechanical Modification of Pulp to Improve the Strength of Paper

2013 ◽  
Vol 848 ◽  
pp. 330-333
Author(s):  
Ai Yun Long ◽  
Chuan Shan Zhao ◽  
De Gui Li ◽  
Yi Fei Jiang ◽  
Wen Jia Han
Keyword(s):  
Biological Treatment ◽  
Fiber Surface ◽  
Strength Properties ◽  
Environmental Scanning ◽  
Paper Strength ◽  
Optimum Conditions ◽  
Scanning Microscope ◽  
Carboxyl Content ◽  
Pulp Consistency ◽  
Pulp Strength

By the preceding experiments, we concluded that the optimum conditions for laccase treatment were: the concentration of laccase 16U/g dry pulp, the pulp consistency 5%, temperature 50 °C, pH=5.0 and reaction time 90min. We studied the change of water retention value and carboxyl content changes under the best conditions. As well as we studied the effect of pulp strength properties by biological treatment combined with mechanical treatment. Moreover, environmental scanning microscope images showed that more collapse and more fibrillation were observed on the beating combined with laccasehistidine-treated fiber surface than the control samples, which led to form better bonding between fibers in handsheets resulting in the increase of the paper strength of beating combined with laccasehistidine-treated OCC pulp.

Research on Biological Modification of Pulp to Improve the Strength of Paper

2013 ◽  
Vol 848 ◽  
pp. 334-337
Author(s):  
Ai Yun Long ◽  
Chuan Shan Zhao ◽  
Wen Jia Han ◽  
Yi Fei Jiang
Keyword(s):  
Control Sample ◽  
Strength Properties ◽  
Raw Material ◽  
Paper Strength ◽  
Optimum Conditions ◽  
Wet Strength ◽  
Tensile Index ◽  
Pulp Consistency ◽  
Pulp Properties ◽  
Biological Modification

Based on the domestic OCC pulp as raw material, it was found that the optimum conditions for laccase treatment were: the concentration of laccase 16U/g dry pulp, the pulp consistency 5%, temperature 50 °C, pH=5.0 and reaction time 90min. OCC treated with laccase alone can improve paper strength properties. The dry tensile index and wet tensile index of the control sample were 21.80 Nm/g and 0.22 Nm/g, respectively. The dry tensile index and wet tensile index after OCC treated with laccase alone were 23.36 Nm/g and 0.28 Nm /g. Comparing to the control pulp, the dry tensile index and wet tensile index of OCC treated with laccase were increased by 6.88% and 27.3%, respectively. At the same time, the laccase system can obviously improve the strength of the pulp properties with adding the mediator, especially using histidine, the dry and wet strength of paper was largely improved.

Characterization of fibers after xylanase and modified laccase-glutamate system biobleaching of old newsprint pulp

2021 ◽  
Vol 36 (1) ◽  
pp. 21-32
Author(s):  
Guozheng Chen ◽  
Jinquan Wan ◽  
Yongwen Ma ◽  
Yan Wang
Keyword(s):  
Fiber Quality ◽  
Average Pore Size ◽  
Fiber Surface ◽  
Strength Properties ◽  
Sem Analysis ◽  
Physical Analysis ◽  
Paper Strength ◽  
Average Pore ◽  
Fine Fiber ◽  
Glutamate System

Abstract The macroscopic and microscopic properties of old newsprint pulp with xylanase, MLac/Glu (modified laccase-glutamate system), and X-MLac/Glu (xylanase synergistic modified laccase-glutamate system) pretreatment was investigated by means of fiber quality measurements (FQA), attenuated total reflectance-infrared spectroscopy (ATR-IR), headspace gas chromatography (HSGC), X-ray diffract ion method (XRD), Low-temperature nitrogen absorption and scanning electron microscopy (SEM). Results showed that, compare with the control pulp, the brightness and lightness ( L ∗ {L^{\ast }} ) of hydrogen peroxide bleached pulp after X-MLac/Glu pretreatment increased by 5.86 % ISO and 3.58 %, respectively. FQA analysis revealed that coarseness and fine fiber content increased slightly. The content of carboxyl groups and water retention value increased remarkably by 31.11 % and 39.22 %, respectively. The paper physical analysis showed that the paper strength properties have improved significantly. The crystallinity of cellulose decreased by 3.82 % due to X-MLac/Glu pretreatment. ATR-IR analysis indicated some non-cellulose components are removed. The BJH average pore size and BET specific surface area increased after enzyme pretreatment. The SEM analysis showed that through X-MLac/Glu treatment the fiber surface becomes rough and the connections between the fibers become tighter, more fibrils appeared.

Variations of fiber structure and performance of ONP delinked pulp after modified-laccase/glutamate treatment

2018 ◽  
Vol 33 (4) ◽  
pp. 618-624 ◽  
Author(s):  
Junjing Dong ◽  
Jinquan Wan ◽  
Yongwen Ma ◽  
Yan Wang
Keyword(s):  
Fiber Quality ◽  
Fiber Surface ◽  
Strength Properties ◽  
Physical Analysis ◽  
Fiber Structure ◽  
Paper Strength ◽  
Amino Groups ◽  
Headspace Gas ◽  
Terminal Amino ◽  
And Performance

Abstract This paper discusses the usage of thiourea dioxide to modify the residual terminal amino groups of amino acid in laccase. The effect of modified-laccase/glutamate treatment on the microstructure and properties of old newspaper deinked pulp was investigated by means of fourier transform infrared spectroscopy and headspace gas chromatography. Results showed that after the modified-laccase/glutamate treatment, the content of carboxyl groups in pulp increased remarkably by 20.8 %. Microscope images showed the fiber filamentation was more obvious, and fibrils content on the fiber surface increased. The fiber quality analyse indicated that fiber coarseness decreased notably but length and width changed a little. The paper physical analysis showed that the paper strength properties had improved remarkably while whiteness decreased slightly.

Enhancement of Pulp Strength by Forming Polyelectrolyte Multilayers on APMP Fibers

2014 ◽  
Vol 496-500 ◽  
pp. 171-174
Author(s):  
Ge Tian ◽  
Yun Yun Sun ◽  
Fan Gong Kong ◽  
Shou Juan Wang ◽  
Jia Chuan Chen
Keyword(s):  
Treatment Time ◽  
Fiber Surface ◽  
Strength Properties ◽  
Polyelectrolyte Multilayers ◽  
Layer By Layer ◽  
Physical Strength ◽  
Alkaline Peroxide ◽  
Treatment Conditions ◽  
Layer Deposition ◽  
Pulp Strength

The layer-by-layer deposition technique was adopted in this paper to improve the physical strength properties of alkaline peroxide mechanical pulp (APMP). The cationic starch (CS), anionic polyacryamide (APAM) and cationic polyacryamide (CPAM) were chosen and used to build-up polyelectrolyte multilayers on surface of APMP fibers. The improvements of physical strength of pulp through adsorption of different polyelectrolyte onto fibers were discussed and compared. The results showed that when the APMP fibers were treated with CPAM, the breaking length and burst index were 53% and 83% respectively, higher than that of untreated pulp. The optimal treatment conditions are 60 mgCPAM/g pulp, 1.5% pulp concentration and 9min treatment time. The pulp deposited by CPAM-APAM polyelectrolyte multilayer gave a highest physical strength compared with pulp with other multilayer deposition such as CS-APAM. At the whole beating degree range investigated in this paper, the CPAM-APAM deposition on fiber surface can improve the physical strength properties significantly, especially when the beating degree is at 40oSR. In addition, the improvement of physical strength can be remained even after pulp refining.

A novel predictive method for filler coflocculation with cellulose microfibrils

TAPPI Journal ◽  
2019 ◽  
Vol 18 (11) ◽  
pp. 653-664
Author(s):  
IGNACIO DE SAN PIO ◽  
KLAS G. JOHANSSON ◽  
PAUL KROCHAK
Keyword(s):  
Negative Impact ◽  
High Strength ◽  
Strength Properties ◽  
Cellulose Microfibrils ◽  
Paper Strength ◽  
Flow Loop ◽  
Cationic Starch ◽  
Reflectance Measurement ◽  
Drainage Rate ◽  
Complete Study

Different strategies aimed at reducing the negative impact of fillers on paper strength have been the objective of many studies during the past few decades. Some new strategies have even been patented or commercialized, yet a complete study on the behavior of the filler flocs and their effect on retention, drainage, and formation has not been found in literature. This type of research on fillers is often limited by difficulties in simulating high levels of shear at laboratory scale similar to those at mill scale. To address this challenge, a combination of techniques was used to compare preflocculation (i.e., filler is flocculated before addition to the pulp) with coflocculation strategies (i.e., filler is mixed with a binder and flocculated before addition to the pulp). The effect on filler and fiber flocs size was studied in a pilot flow loop using focal beam reflectance measurement (FBRM) and image analysis. Flocs obtained with cationic polyacrylamide (CPAM) and bentonite were shown to have similar shear resistance with both strategies, whereas cationic starch (CS) was clearly more advantageous when coflocculation strategy was used. The effect of flocculation strategy on drainage rate, STFI formation, ash retention, and standard strength properties was measured. Coflocculation of filler with CPAM plus bentonite or CS showed promising results and produced sheets with high strength but had a negative impact on wire dewatering, opening a door for further optimization.

Further understanding the influence of fiber surface and internal charges on the interfiber bonding capability and resulting paper strength

Cellulose ◽  
2017 ◽  
Vol 24 (7) ◽  
pp. 2977-2986 ◽  
Author(s):  
Chengke Zhao ◽  
Hongjie Zhang ◽  
Zhiqiang Li ◽  
Fengshan Zhang ◽  
Xiaoliang Li
Keyword(s):  
Fiber Surface ◽  
Paper Strength

scholarly journals Chemical characteristics and Kraft pulping of tension wood from Eucalyptus globulus labill

2012 ◽  
Vol 36 (6) ◽  
pp. 1163-1172 ◽  
Author(s):  
María Graciela Aguayo ◽  
Regis Teixeira Mendonça ◽  
Paulina Martínez ◽  
Jaime Rodríguez ◽  
Miguel Pereira
Keyword(s):  
Eucalyptus Globulus ◽  
Lignin Content ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Pulp Yield ◽  
Chemical Characteristics ◽  
Kraft Pulps ◽  
Opposite Wood ◽  
Alkali Consumption ◽  
Pulp Strength

Tension (TW) and opposite wood (OW) of Eucalyptus globulus trees were analyzed for its chemical characteristics and Kraft pulp production. Lignin content was 16% lower and contained 32% more syringyl units in TW than in OW. The increase in syringyl units favoured the formation of β-O-4 bonds that was also higher in TW than in OW (84% vs. 64%, respectively). The effect of these wood features was evaluated in the production of Kraft pulps from both types of wood. At kappa number 16, Kraft pulps obtained from TW demanded less active alkali in delignification and presented slightly higher or similar pulp yield than pulps made with OW. Fiber length, coarseness and intrinsic viscosity were also higher in tension than in opposite pulps. When pulps where refined to 30°SR, TW pulps needed 18% more revolutions in the PFI mill to achieve the same beating degree than OW pulps. Strength properties (tensile, tear and burst indexes) were slightly higher or similar in tension as compared with opposite wood pulps. After an OD0(EO)D1 bleaching sequence, both pulps achieved up to 89% ISO brightness. Bleached pulps from TW presented higher viscosity and low amount of hexenuronic acids than pulps from OW. Results showed that TW presented high xylans and low lignin content that caused a decrease in alkali consumption, increase pulp strength properties and similar bleaching performance as compared with pulps from OW.

Rapid and Efficient Wet Fixation by the Use of Steam

1969 ◽  
Vol 39 (6) ◽  
pp. 497-504 ◽  
Author(s):  
Norman R. S. Hollies ◽  
Steven R. Chafitz ◽  
Karen A. Farquhar
Keyword(s):  
Fiber Surface ◽  
Strong Acid ◽  
Strength Properties ◽  
Fiber System ◽  
Resin Solution ◽  
Speed Up ◽  
Drying Properties ◽  
The Individual ◽  
Time Required ◽  
Finishing Processes

The impregnation of cotton fabrics with a solution consisting of strong acid and a combination of N-methylol resins having polymer-forming and cross-linking properties distinguishes the wet-fixation system from conventional durable-press processes, and this finish results in an improved balance of smoothness and strength properties during wear and laundering. Swelling of the fibers in a steam atmosphere, following padding in the resin solution can serve to speed up the impregnation process. In addition, with controls to minimize resin migration back to the fiber surface, steaming can substantially improve the efficiency of the use of resin for producing these smooth drying properties. The degree of penetration of resin is influenced by a number of process variables, such as predrying before steaming, steaming time, fabric tension and rapidity of neutralization. The optimum in fabric performance is achieved with both sufficient resin of both types in the fiber system and even distribution of resin within the individual fibers, Steaming acts to improve both these factors over that achieved in conventional hot wet fixation and so reduces the time required for wet fixation by a factor of 20–30. There is a corresponding increase in efficiency of resin use so that resin solids in the bath can be reduced two- to three-fold. These findings appear to have general application to a variety of cotton finishing processes involving fiber impregnation with reactive resins.

Influence of cellulose supramolecular structure on strength properties of chemical pulp

Holzforschung ◽  
2014 ◽  
Vol 68 (8) ◽  
pp. 861-866 ◽  
Author(s):  
Per Tomas Larsson ◽  
Lennart Salmén
Keyword(s):  
Supramolecular Structure ◽  
Strength Properties ◽  
Cellulose Microfibrils ◽  
Kraft Pulps ◽  
Chemical Pulp ◽  
Chemical Pulps ◽  
Fiber Wall ◽  
Tear Index ◽  
Pulp Strength ◽  
Selective Increase

Abstract The industrially produced chemical pulps have lower strength properties than those obtained under laboratory conditions, and this difference is referred to as the strength delivery (SD) problem. In this study, the hypothesis was put forward that the SD could, at least in part, be accounted for by the supramolecular structure of the cellulose microfibrils of the fiber wall. To test the hypothesis, two bleached softwood kraft pulps (BSKP) were manufactured from the same starting material with different degrees of cellulose aggregation, but the pulps were otherwise as similar as possible in other controllable respects. The chemical and physical properties, including the pulp strength, were tested. A selective increase of the degree of cellulose microfibril aggregation resulted in a pulp with a decreased tear index (TI) at a specified tensile index, and this decrease was similar in magnitude to what is typically encountered in SD. Accordingly, the current experimental study succeeded in mimicking the SD problem. The lateral fibril aggregate dimensions (LFAD) seem to play a pivotal role and it can be safely concluded in general that the supramolecular structure of cellulose in the fibers may be an important factor contributing to the SD problem.

Assessment of magnesium ammonium phosphate precipitation for the treatment of leather tanning industry wastewaters

2002 ◽  
Vol 46 (4-5) ◽  
pp. 231-239 ◽  
Author(s):  
I. Kabdaşli ◽  
O. Tünay ◽  
M.Ş. Çetin ◽  
T. Ölmez
Keyword(s):  
Biological Treatment ◽  
Ammonium Phosphate ◽  
Chemical Precipitation ◽  
Optimum Conditions ◽  
Magnesium Ammonium Phosphate ◽  
Ammonium Removal ◽  
Leather Tanning ◽  
Magnesium Ammonium ◽  
Recent Method ◽  
Study Application

Magnesium ammonium phosphate (MAP) precipitation has a potential for ammonium removal from industrial wastewaters. Application basis of this recent method of treatment has not been fully determined. In this study application of MAP precipitation to leather tanning wastewaters has been experimentally evaluated. Five alternative places of MAP precipitation in leather tanning wastewater treatment scheme tested were; instead of plain settling, after plain settling, after polyelectrolyte added plain settling, within the chemical precipitation and after biological treatment. Among these alternatives MAP application instead of plain settling and within the chemical precipitation were found to be most favourable and efficient by reducing the nitrogen load to the level of nutrient requirement in the biological stage. pH 9.0-9.5 and stoichiometric magnesium and phosphate doses were determined to be optimum conditions for MAP precipitation.

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