Acid methanolysis: An analytical tool for estimating the proportions of different pulp types in deinked pulp or recovered paper

A method was developed to estimate the composition of deinked pulp or recovered paper in termsof hardwood kraft pulp, softwood kraft pulp, and mechanical pulp through analysis of the sugar units in hemicellulosesand pectins. Different pulps (i.e., bleached chemical pulp from hardwoods and softwoods and mechanical pulp) were obtainednfrom different mills. The pulps were mixed in different proportions and dried. The content of arabinose, xylose, mannose, galactose, rhamnose, galacturonic acid, and 4-O-methyl-glucuronic acid, sugar units in hemicelluloses and pectins in the different pulps and in the mixtures were determined by acid methanolysis and gas chromatography. The contents of the sugar units were significantly different in the three pulp types but quite similar in the same pulp type, irrespectively of bleaching sequence. The modeling was performed using standard partial least squares regression (PLSR) and cross-validation using venetian blinds subsets. The data were autoscaled before regressions. The best model had two latent variables. The cumulative variation of X captured by the model was 0.988 (R2X), the cumulative variation of Y captured by the model was also 0.988 (R2Y), and the cumulative cross-validated variation of Y captured by the model was 0.974 (Q2). Accordingly, the PLS model is more than capable of predicting the validation set. It was concluded that the proportion of chemical pulp from hardwoods, chemical pulp from softwoods, and mechanical pulp can be estimated in recovered paper or deinked pulp using a mathematical model based on the content of selected sugar units in hemicelluloses and pectins.

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Research on Production of Hand Towel from the Poplar Extruding Mechanical Pulp (EMP)

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.550-553.3253 ◽

2012 ◽

Vol 550-553 ◽

pp. 3253-3257

Author(s):

Xian Qi Sun ◽

Chuan Shan Zhao ◽

Hui Rong Yang

Keyword(s):

Kraft Pulp ◽

Lower Cost ◽

Raw Materials ◽

Raw Material ◽

Public Places ◽

Mechanical Pulp ◽

Tissue Paper ◽

Chemical Pulp ◽

Bleached Kraft Pulp ◽

High Level

Hand towel is one kind of disposable tissue paper which has characteristic of soaking up water quickly and lower cost. It becomes increasingly popularity in families, at work, and public places. There are many kinds of raw materials to produce hand towel according to its level. Some researches showed that bleached chemical pulp could be partially used to the production of hand towel and some other household paper. In this study, some kinds of raw material which be used to produce hand towel were analyzed and trying to looking for new one. Poplar Extruding Mechanical Pulp (EMP) had characteristics of long fiber, high level of strength and brightness. Different ratio of poplar EMP and certain Bleached Kraft Pulp were tested to make hand towel. The effects of poplar EMP on whiteness, tensile strength, bulkiness, absorbability were discussed. The results showed that characteristic targets of hand towel made from poplar EMP and Bleached Kraft Pulp met the quality requirements of GBT22455-2009 and satisfied the high-end hand towel. The new hand towel had lower cost, higher stiffness and higher bulkiness. It was feasible from the technique and economy point.

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Use of fines-enriched chemical pulp to increase CTMP strength

TAPPI Journal ◽

10.32964/tj20.4.255 ◽

2021 ◽

Vol 20 (4) ◽

pp. 255-263

Author(s):

ELISABETH BJORK ◽

MIKAEL BOUVENG ◽

HANNES VOMHOFF ◽

PER ENGSTRAND

Keyword(s):

Kraft Pulp ◽

Fine Fraction ◽

Strength Properties ◽

Strength Increase ◽

Fines Content ◽

Chemical Pulp ◽

Softwood Kraft Pulp

In this study, fines-enriched pulp (FE-pulp)—the fine fraction of highly-refined kraft pulp—was benchmarked against highly-refined kraft pulp (HRK-pulp) as a strength agent in eucalyptus chemithermomechanical pulp (CTMP). Both the FE-pulp and the HRK-pulp were produced from unbleached softwood kraft pulp, and equal amounts of those strength agents were added to the original CTMP, as well as to washed CTMP, where most of the fines had been removed. The effects of the added strength agents were evaluated with laboratory handsheets. The FE-pulp proved to be twice as effective as HRK-pulp. Both HRK-pulp and FE-pulp increased the strength of the CTMP handsheets. The bulk of the handsheets decreased, however, as well as the drainability. The addition of 5% FE-pulp resulted in the same strength increase as an addition of 10% HRK-pulp, as well as the same decrease in bulk and CSF. For the handsheets of washed CTMP, the strengths were not measurable; the CTMP lost the sheet strength when the CTMP-fines content was reduced through washing. The reduced strength properties were compensated for by the addition of chemical pulp fines that proved to be an efficient strength agent. The addition of 5% FE-pulp restored the strength values, and at a higher bulk and higher drainability.

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The effect of molecular composition of xylan extracted from birch on its assembly onto bleached softwood kraft pulp

Holzforschung ◽

10.1515/hf.2006.023 ◽

2006 ◽

Vol 60 (2) ◽

pp. 143-148 ◽

Cited By ~ 31

Author(s):

Peter Westbye ◽

Christer Svanberg ◽

Paul Gatenholm

Keyword(s):

Kraft Pulp ◽

Glucuronic Acid ◽

Surface Composition ◽

Control Sample ◽

Aggregate Size ◽

Cellulose Microfibrils ◽

Kraft Pulps ◽

Chemical Surface ◽

Carbon Carbon Bonds ◽

Softwood Kraft Pulp

Abstract The effect of the molecular structure of xylan on its assembly onto softwood kraft pulps was investigated. Various xylan-rich fractions were isolated from birch wood chips by different mild treatments using water (H2O), acetic acid (HAc) and sulfur dioxide (SO2). The isolation involved prehydrolysis followed by alkaline extraction, with only the time, temperature and medium in the prehydrolysis step varied. After separation, the fractions were neutralised (pH 7) and some material agglomerated and became insoluble. Dynamic light scattering measurements revealed differences in aggregate size among the different fractions. The fractions that agglomerated to the greatest extent contained less glucuronic acid and a higher amount of lignin. Such fractions adsorbed to a significantly higher extent (25.5% compared to 5.0% for the lowest soluble fraction) onto bleached softwood kraft pulps in experiments performed in autoclaves. The adsorption was carried out with fixed process parameters (100°C, pH 10, 120 min). The adsorption of various xylan fractions resulted in different surface morphology on cellulose microfibrils, as observed by AFM. Pulps treated with xylans that were soluble at pH 7 showed small differences from the control sample, which was treated in an autoclave without the addition of xylan. Pulps treated with xylans that agglomerated at pH 7 showed a greater difference in the amount of nanosized aggregates covering the surface. ESCA analysis of the chemical surface composition indicated that samples containing more lignin showed a greater shift towards carbon-carbon bonds. A novel sequence for a pulping process is suggested.

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EFEKTIVITAS BERBAGAI INDIKATOR PENGGILINGAN UNTUK MEMPREDIKSI KUALITAS KERTAS

JURNAL SELULOSA ◽

10.25269/jsel.v1i02.22 ◽

2016 ◽

Vol 1 (02) ◽

Author(s):

Hana Rachmanasari ◽

Taufan Hidayat

Keyword(s):

Kraft Pulp ◽

Wood Pulp ◽

Strength Properties ◽

Raw Material ◽

Fiber Morphology ◽

Mechanical Pulp ◽

Chemical Pulp ◽

Bleached Kraft Pulp ◽

Drainage Rate

The experiments of refining have been done using PFI mill and Beater, at 300 mL CSF of freenessas fixed parameters. Research was aims to determine the effective indicators of refining to predict the quality of the paper. The raw material used were wood pulp, non wood pulp, chemical pulp, mechanical pulp, Leaf Bleached Kraft Pulp (LBKP) and Needle Bleached Kraft Pulp (NBKP). The parameters which analyzed for each equipments were fibers classification, fiber morphology, dimensions of its derivatives and as the value of the drainage rate. The strenght of handsheets formed from the fibers were tested including tensile, bursting, and tearing strength. According to the results of correlation analysis, the most effective and sensitive indicators of refining towards strength properties of paper, in the wo different refining methods, is the felting power slenderness with correlation values above 0.8.Key words : refining, fiber classification, fiber morphology, the strength properties, correlation valueABSTRAKTelah dilakukan percobaan penggilingan menggunakan PFI mill dan Valley Beater, pada freeness 300 mL CSF sebagai parameter tetap. Penelitian ini bertujuan untuk mengetahui beberapa indikator penggilingan yang efektif untuk memprediksi kualitas kertas. Bahan baku terdiri dari pulp kayu, pulp non kayu, pulp kimia, pulp mekanis, pulp kayudaun dan pulp kayujarum. Parameter yang dianalisa untuk masing-masing hasil penggilingan adalah klasifikasi serat, morfologi serat dan dimensi turunannya serta nilai laju drainase. Selanjutnya dilakukan uji sifat kekuatan yang meliputi ketahanan tarik, retak dan sobek. Berdasarkan hasil analisa korelasi terhadap data penelitian, indikator penggilingan yang paling efektif dan sensitif terhadap sifat kekuatan kertas pada dua metode penggilingan berbeda adalah kelangsingan dengan nilai korelasi di atas 0,8.Kata kunci : penggilingan, klasifikasi serat, morfologi serat, sifat kekuatan, nilai korelasi

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Optimization of elemental chlorine-free bleaching for a softwood kraft pulp • part 2: economic analysis of chemical and steam consumption

TAPPI Journal ◽

10.32964/tj9.9.47 ◽

2010 ◽

Vol 9 (9) ◽

pp. 47-53 ◽

Cited By ~ 2

Author(s):

BRIAN N. BROGDON

Keyword(s):

Chlorine Dioxide ◽

Previous Investigation ◽

Kraft Pulp ◽

Energy Costs ◽

Alkaline Extraction ◽

Stage Versus ◽

Kraft Pulps ◽

Steam Consumption ◽

Elemental Chlorine ◽

Softwood Kraft Pulp

Our previous investigation [1] re-analyzed the data from Basta and co-workers (1992 TAPPI Pulping Conference) to demonstrate how oxidative alkaline extraction can be augmented and how these changes affect chlorine dioxide consumption with elemental chlorine-free (ECF) sequences. The current study manipulates extraction delignification variables to curtail bleaching costs with a conventional U.S. Southern softwood kraft pulp. The economic advantages of ~0.35% to 0.65% H2O2 peroxide reinforcement in a 70°C (EOP)-stage versus 90°C (EO)-stage are predisposed to the brightness targets, to short or long bleach sequences, and to mill energy costs. Minimized bleaching costs are generally realized when a 90°C (EO) is employed in D0(EO)D1 bleaching, whereas a 70°C (EOP) is economically advantageous for D0(EOP)D1E2D2 bleaching. The findings we disclose here help to clarify previous ECF optimization studies of conventional softwood kraft pulps.

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An effective method for determining the retention and distribution of cellulose nanofibrils in paper handsheets by dye labeling

TAPPI Journal ◽

10.32964/tj17.03.157 ◽

2018 ◽

Vol 17 (03) ◽

pp. 157-164 ◽

Cited By ~ 3

Author(s):

Shengdan Wang ◽

Wenhua Gao ◽

Kefu Chen ◽

Jinsong Zeng ◽

Jun Xu ◽

...

Keyword(s):

Correlation Coefficient ◽

Congo Red ◽

Kraft Pulp ◽

Cellulose Nanofibrils ◽

Standard Curve ◽

Congo Red Dye ◽

Mechanical Disintegration ◽

Softwood Kraft Pulp ◽

White Water ◽

Red Dye

Cellulose nanofibrils (CNF) were prepared by cellulase in conjunction with mechanical disintegration from the bleached softwood kraft pulp and labelled by Congo red dye. The labelled CNF were used to investigate the retention and distribution of CNF in paper handsheets. The retention of the labelled CNF was obtained by measuring the absorbance of white water using an ultraviolet-visible spectrophotometer. The results showed that this method for measuring the retention was rapid, feasible, and sensitive, owing to the high correlation coefficient R2 (0.9993) of the standard curve. The labelled CNF showed even distribution in paper handsheets. The colorimetric values of paper handsheets were explored with a residual ink analyzer.

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