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

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.

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Wet-peel: a tool for comparing wet-strength resins

Nordic Pulp & Paper Research Journal ◽

10.1515/npprj-2018-0013 ◽

2018 ◽

Vol 33 (4) ◽

pp. 632-646 ◽

Cited By ~ 3

Author(s):

Dong Yang ◽

John-Louis DiFlavio ◽

Emil Gustafsson ◽

Robert Pelton

Keyword(s):

Fiber Surface ◽

Testing Procedure ◽

Regenerated Cellulose ◽

Pulp Fiber ◽

Layer By Layer ◽

Paper Strength ◽

Wet Strength ◽

Polyelectrolyte Complexes ◽

Cellulose Membranes ◽

Web Strength

Abstract We propose that a testing procedure we call wet-peel significantly augments conventional wet paper testing when comparing wet-strength resin efficacy or the influence wood pulp fiber surface treatments on wet paper strength. A thin layer of wet-strength resin is sandwiched between a pair of thin, wet regenerated cellulose membranes to form a laminate, which is a physical model for fiber-fiber joints in paper. In the wet-peel method, the ninety-degree wet-delamination force gives a direct measure of adhesion in the wet cellulose-cellulose joint. Wet-peel measurements offer: 1) comparisons of wet-strength polymers at the same content of polymer in the laminate joint without the influences of varying fines contents, formation or paper density; 2) measurements of both the wet-strength of cured, dried joints, and the strength of never-dried joints (i. e. analogous to wet-web strength); 3) demonstrations of the influence of fiber surface chemistry modifications including oxidation and the presence of firmly bound polymers; and, 4) the evaluation of more exotic joint structures including layer-by-layer assemblies, microgels and colloidal polyelectrolyte complexes.

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

Nordic Pulp & Paper Research Journal ◽

10.1515/npprj-2018-0025 ◽

2018 ◽

Vol 33 (4) ◽

pp. 618-624 ◽

Cited By ~ 1

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.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.848.330 ◽

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.

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OPTIMASI BIOPROSES MODIFIKASI PERMUKAAN SERAT UNTUK PENINGKATAN KEKUATAN KERTAS

JURNAL SELULOSA ◽

10.25269/jsel.v4i01.56 ◽

2016 ◽

Vol 4 (01) ◽

Author(s):

Taufan Hidayat ◽

Nina Elyani ◽

Chandra Apriana Purwita

Keyword(s):

Surface Modification ◽

Reaction Times ◽

Fiber Surface ◽

Mechanical Action ◽

Agitation Speed ◽

Acetobacter Xylinum ◽

Main Process ◽

Paper Strength ◽

Short Fibers ◽

Active Volume

Fiber surface modification is a main process to improve paper quality. It is usually done mechanically through refining process. In this research the modification was done microbiologically by using Acetobacter xylinum. In principle, this process is carried out by growing bacterial cellulose on the fiber surface, which is similar to fibrillation by mechanical action. The modification was done at the short fibers at 5 duration reaction times and 4 level agitation speeds. The experiments were conducted in a 75 liter active volume bioreactor filled with a liquid inorganic media, 0.75% pulp consistency, at 30°C temperature, and pH 5.5. The washed pulp was then turned into sheets for testing purposes. The experiments show that at 37.5 Hz agitation speed and 1-3 hours reaction time, the paper strength and structure improve effectively. In addition, this optimized process also shows a potential energy saving up to 17.24% at agitation speed of 25,0 Hz.Keywords: fiber surface modification, Acetobacter xylinum, paper strength, short fibers ABSTRAK Modifikasi permukaan serat adalah proses inti pembuatan kertas untuk meningkatkan kualitas kertas. Pada umumnya modifikasi permukaan serat dilakukan secara mekanis melalui proses penggilingan. Pada penelitian ini modifikasi permukaan serat dilakukan secara mikrobiologis menggunakan Acetobacter xylinum. Proses ini berlangsung dengan cara menumbuhkan bakteri pembentuk selulosa pada permukaan serat sehingga serat terfibrilasi. Penelitian dilakukan pada serat pendek dengan variasi 5 durasi waktu reaksi dan 4 tingkat kecepatan agitasi. Proses modifikasi dilakukan dalam bioreaktor dengan volume aktif 75 liter menggunakan media anorganik cair, pada konsistensi pulp 0,75%, suhu 30°C, dan pH 5,5. Pulp hasil reaksi dicuci kemudian dibuat lembaran untuk diuji karakteristik fisiknya. Hasil pengamatan menunjukkan bahwa pada kondisi kecepatan agitasi 37,5 Hz dan waktu inkubasi 1-3 jam, bioproses modifikasi serat efektif untuk meningkatkan kekuatan kertas, memperbaiki struktur lembaran kertas, dan berpeluang menghemat energi sebesar 17,24% pada kecepatan agitasi 25,0 Hz.Kata kunci: modifikasi permukaan serat, Acetobacter xylinum, kekuatan kertas, serat pendek

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Influence of Fiber Surface Energy on Mechanical Properties of Sisal Fiber - Bio Based Epoxy Composites

JOURNAL OF POLYMER MATERIALS ◽

10.32381/jpm.2018.35.04.7 ◽

2019 ◽

Vol 35 (4) ◽

pp. 485-496

Author(s):

S. RAJKUMAR ◽

◽

R. JOSEPH BENSINGH ◽

M. ABDUL KADER ◽

SANJAY K NAYAK ◽

...

Keyword(s):

Mechanical Properties ◽

Surface Energy ◽

Fiber Surface ◽

Epoxy Composites ◽

Sisal Fiber

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Polysulfide-borohydride modification of southern pine alkaline pulping integrated with hydrothermal pre-extraction of hemicelluloses

TAPPI Journal ◽

10.32964/tj10.7.9 ◽

2011 ◽

Vol 10 (7) ◽

pp. 9-16

Author(s):

SUNG-HOON YOON ◽

HARRY CULLINAN ◽

GOPAL A. KRISHNAGOPALAN

Keyword(s):

Loblolly Pine ◽

Sodium Borohydride ◽

Kraft Pulping ◽

Hot Water ◽

Pulp Yield ◽

Paper Strength ◽

Southern Pine ◽

Two Stage ◽

Simultaneous Treatment ◽

Process Modification

We studied three process modifications to investigate their effects on the property and yield recovery capabilities of kraft pulping integrated with hemicellulose pre-extraction of southern pine. Loblolly pine chips were pre-extracted with hot water until the sugar extraction yield reached the targeted value of 10% and then subjected to conventional and modified kraft pulping. Modification included polysulfide pretreatment; polysulfide-sodium borohydride dual pretreatment, and polysulfide followed by polysulfide-sodium borohydride dual pretreatment two-stage pretreatments prior to kraft pulping. In the first modification, about 5% of the lost pulp yield (total 7%) caused by hemicellulose pre-extraction could be recovered with 15%-20% polysulfide pretreatment. Complete recovery (7%) was achieved with simultaneous pretreatment using 15% polysulfide and 0.5% sodium borohydride with 0.1% anthraquinone in polysulfide-sodium borohydride dual pretreatment. Two-stage pretreatment using recycled 15% polysulfide followed by simultaneous treatment of 6% polysulfide and 0.4%–0.5% sodium borohydride with 0.1% anthraquinone also achieved 100% yield recovery. Continuous recycling of 15% polysulfide employed in the two-stage process modification maintained its yield protection efficiency in a repeated recycling cycle. No significant changes in paper strength were found in handsheets prepared from the three process modifications, except for a minor reduction in tear strength.

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Impact of fiber structure on edge-wicking of highly-sized paperboard

TAPPI Journal ◽

10.32964/tj17.08.437 ◽

2018 ◽

Vol 17 (08) ◽

pp. 437-443

Author(s):

Lebo Xu ◽

Jeremy Meyers ◽

Peter Hart

Keyword(s):

Fiber Surface ◽

Manufacturing Processes ◽

Paper Machine ◽

Liquid Penetration ◽

Fiber Structure ◽

Cut Edge ◽

Local Fiber

Coffee edge-wicking testing was conducted on two groups of highly-sized paperboard manufactured at two mills with similar manufacturing processes, but with vastly different local fiber sources. Although the Hercules size test (HST) indicated similar internal size levels between the two types of board, the edge-wicking behavior was noticeably different. Analysis of fiber structure revealed that the board with more edge-wicking had fibers with thicker fiber walls, which kept the fiber lumen more open after pressing and drying on a paper machine. It was demonstrated that liquid penetration through voids between fibers in highly-sized paperboard was limited, because the fiber surface was well protected by the presence of sufficient sizing agent. Nevertheless, freshly exposed fiber walls and lumens at the cut edge of the sheet were not protected by sizing material, which facilitated edge-wicking. The correlation between fiber structure and edge-wicking behavior was highlighted in this work to inspire development of novel sizing strategies that protect the freshly cut edge of the sheet from edge-wicking.

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Complex formation of modified chitosan and carboxymethyl cellulose and its effect on paper properties

TAPPI Journal ◽

10.32964/tj8.6.29 ◽

2009 ◽

Vol 8 (6) ◽

pp. 29-35 ◽

Cited By ~ 11

Author(s):

PEDRAM FATEHI ◽

LIYING QIAN ◽

RATTANA KITITERAKUN ◽

THIRASAK RIRKSOMBOON ◽

HUINING XIAO

Keyword(s):

Carboxymethyl Cellulose ◽

Polymer System ◽

Layer By Layer ◽

Paper Strength ◽

Anionic Polymer ◽

Paper Properties ◽

Modified Chitosan ◽

Layer By Layer Assembly ◽

Polyelectrolyte Titration ◽

Layer Assembly

The application of an oppositely charged dual polymer system is a promising approach to enhance paper strength. In this work, modified chitosan (MCN), a cationic polymer, and carboxymethyl cellulose (CMC), an anionic polymer, were used sequentially to improve paper strength. The adsorption of MCN on cellulose fibers was analyzed via polyelectrolyte titration. The formation of MCN/CMC complex in water and the deposition of this complex on silicon wafers were investigated by means of atomic force microscope and quasi-elastic light scattering techniques. The results showed that paper strength was enhanced slightly with a layer-by-layer assembly of the polymers. However, if the washing stage, which was required for layer-by-layer assembly, was eliminated, the MCN/CMC complex was deposited on fibers more efficiently, and the paper strength was improved more significantly. The significant improvement was attributed to the extra development of fiber bonding, confirmed further by scanning electron microscope observation of the bonding area of fibers treated with or without washing. However, the brightness of papers was somewhat decreased by the deposition of the complex on fibers. Higher paper strength also was achieved using rapid drying rather than air drying.

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A novel predictive method for filler coflocculation with cellulose microfibrils

TAPPI Journal ◽

10.32964/tj18.11.653 ◽

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.

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