Desorption of Cationic Polyacrylamide from Bleached Kraft Pulp Fibers

The adsorption and desorption behaviour of a cationic polyelectrolyte contacted with wood pulp fibers was determined by total nitrogen analysis using a pyrolysis/chemiluminescence detection system. Dialysed polymer generated an adsorption isotherm of higher affinity than did non-dialysed polymer. Capacity adsorption was maximized at pH 7, but decreased in the presence of alum depending on the dosage. Desorption of non-dialysed polymer was caused by changes in pH above or below 7.0 as well as by addition of alum. However for the alum doses typically encountered in paper manufacturing, significant desorption is unlikely. Nevertheless, the contaminants in non-dialysed polymers do hinder adsorption, and effluents from those processes using both alum and polymer may contain quantities of unadsorbed or desorbed polyelectrolytes which could be damaging to receiving water bodies.

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Xylanase-Induced Liberation of Negatively Charged Species and Their Effect on Colloidal Interactions and the Retention of Bleached Kraft Pulp Fibers

BioResources ◽

10.15376/biores.10.3.5460-5475 ◽

2015 ◽

Vol 10 (3) ◽

Author(s):

Katja Eliisa Lyytikäinen ◽

Kaj Backfolk

Keyword(s):

Kraft Pulp ◽

Pulp Fibers ◽

Charged Species ◽

Colloidal Interactions ◽

Bleached Kraft Pulp

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Fold cracking of coated paper: The effect of pulp fiber composition and beating

Nordic Pulp & Paper Research Journal ◽

10.3183/npprj-2012-27-02-p445-450 ◽

2012 ◽

Vol 27 (2) ◽

pp. 445-450 ◽

Cited By ~ 11

Author(s):

Hye Jung Youn ◽

Kyujeong Sim ◽

Kyu Deok Oh ◽

Hak Lae Lee ◽

Chang Sun Han ◽

...

Keyword(s):

Tensile Strength ◽

Kraft Pulp ◽

Low Cost ◽

Pulp Fiber ◽

Mixing Ratio ◽

Pulp Fibers ◽

Coated Paper ◽

Mixing Ratios ◽

Bleached Kraft Pulp ◽

Base Paper

Abstract Fold cracking of coated papers has become important because of the increase in the coat weight and the content of low cost co-binder. The effects of base paper characteristics of coated paper were investigated to reduce fold cracking. We evaluated the fold cracking of coated paper prepared with different mixing ratios and beating degrees of pulp fibers. Hardwood bleached kraft pulp (Hw-BKP) and softwood bleached kraft pulp (Sw- BKP) were used to prepare base papers for coating. The mechanical and structural properties of base paper such as tensile strength, strain at break, short span compressive strength, and formation were measured. The fold cracking was affected by mixing ratio of pulp fibers. Base paper consisting of Hw-BKP and Sw-BKP at a 90:10 mixing ratio showed the least fold cracking. When the amount of Sw-BKP was greater than 10% or if only Hw- BKP was used, the fold cracking increased on coated paper. When the pulp was highly beaten, the mechanical strength of paper was improved, but the fold cracking was severe. An increase in the tensile strength did not reduce the fold cracking.

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Significant contribution of fibrils on pulp fiber surface to water retention value

Nordic Pulp & Paper Research Journal ◽

10.1515/npprj-2018-0041 ◽

2020 ◽

Vol 35 (1) ◽

pp. 96-105

Author(s):

Minoru Kimura ◽

Takashi Ishida ◽

Yuko Ono ◽

Miyuki Takeuchi ◽

Akira Isogai

Keyword(s):

Cell Walls ◽

Kraft Pulp ◽

Water Retention ◽

Structural Changes ◽

Significant Contribution ◽

Fiber Surface ◽

Pulp Fiber ◽

Pulp Fibers ◽

Bleached Kraft Pulp ◽

Two Factors

AbstractThe contribution of structural changes of softwood bleached kraft pulp (SBKP) fibers and partly dried SBKP handsheets to their water retention values (WRVs) was studied. Two factors related to mesopores and macropores, which were determined for super critical point (SCP)-dried SBKP sheet samples, should participate in the WRVs determined for wet SBKP sheet samples. The mesopores are formed during pulping/bleaching to remove lignin and a part of hemicelluloses that are present originally in wood cell walls. The combined volumes of mesopores and macropores (totally < ∼0.6 g g−1) in SBKP fibers after SCP drying were significantly lower than the entire WRV (∼1.6 g g−1) of the original never-dried SBKP. We hypothesize that external fibrils of SBKP fibers are formed during pulping, bleaching, washing, pressure-screening, and pressing processes at high and low solid contents in water under high shear forces. The WRV can be used as an indicator to evaluate such structural changes of external fibrils in pulp fibers and paper sheets during drying/wetting in papermaking process as well as in use under various conditions. In contrast, changes in mesopore and macropore volumes determined for SCP-dried sheets cannot properly detect such structural changes of external fibrils.

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The effect of hemicellulose extraction on fiber charge properties and retention behavior of kraft pulp fibers

BioResources ◽

10.15376/biores.6.1.219-231 ◽

2010 ◽

Vol 6 (1) ◽

pp. 219-231

Author(s):

Katja Lyytikäinen ◽

Esa Saukkonen ◽

Isko Kajanto ◽

Jari Käyhkö

Keyword(s):

Surface Charge ◽

Kraft Pulp ◽

Paper Industry ◽

Fiber Surface ◽

Pulp Fibers ◽

Paper Properties ◽

Bleached Kraft Pulp ◽

Filler Retention ◽

Anionic Groups ◽

Generation Technology

The integrated forest biorefinery (IFBR) concept provides a promising opportunity for the development of the pulp and paper industry. One proposed next generation technology for an integrated forest biorefinery is the extraction of hemicelluloses, allowing the co-production of pulp and different hemicellulose-based chemicals. In addition to paper properties, hemicelluloses are known to be important for the function of cationic papermaking additives, because they are the main source of charged groups in fibers. This paper shows that the alkaline extraction of hemicelluloses from bleached kraft pulp decreases both the total and surface charge of the pulps. It was found that the decreased fiber charge leads to increased filler retention with fixed retention aid dosage. The reduction observed in the fiber surface charge for alkali-extracted pulp was mainly attributed to the decrease in the amount of anionic groups located in fines.

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Application of Advanced Wet-End System Using Carboxymethyl Cellulose to Mixed Pulp Slurries for Wood-Containing Paper Production

TAPPI Journal ◽

10.32964/tj8.5.32 ◽

2009 ◽

Vol 8 (5) ◽

pp. 32-37

Author(s):

TOMOHISA GONDO ◽

MASASUKE WATANABE ◽

OSAMU KITAO ◽

AKIRA ISOGAI

Keyword(s):

Carboxymethyl Cellulose ◽

Kraft Pulp ◽

Structural Changes ◽

Aluminum Sulfate ◽

Negative Charge ◽

Thermomechanical Pulp ◽

Pulp Fibers ◽

Anionic Sites ◽

Bleached Kraft Pulp ◽

Modification Technique

A pulp modification technique using carboxymethyl cellulose (CMC) at the wet end was applied to mixed pulp slurries containing softwood bleached kraft pulp (SBKP), deinked pulp (DIP), and hydrogen peroxide-bleached thermomechanical pulp (TMP). Introduction of anionic sites by adsorption of the added CMC molecules on the fibers was confirmed by an increase in negative charge of the mixed pulp fibers. Sizing degree of the handsheets prepared with 2% aluminum sulfate and 0.2% rosin dispersion size was clearly improved by 0.1% CMC addition. On the other hand, we observed no significant differences in rosin size content between the handsheets prepared with and without CMC. These results indicate that some mechanisms other than enhancement of rosin size retention may have brought about the clear improvement of sizing performance by the CMC addition. Changes in distribution of rosin size components or some structural changes of rosin size components in the handsheets by the CMC addition may be candidates for sizing development. The CMC addition technique at the wet end is, therefore, also applicable to mixed pulps containing DIP and TMP.

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Influence of recycling and temperature on the swelling ability of paper

Chemical Papers ◽

10.2478/s11696-011-0089-z ◽

2011 ◽

Vol 65 (6) ◽

Cited By ~ 7

Author(s):

Erika Letková ◽

Michal Letko ◽

Milan Vrška

Keyword(s):

Kraft Pulp ◽

Natural Fibers ◽

Swelling Kinetics ◽

Pulp Fibers ◽

Bleached Kraft Pulp ◽

Modified Method ◽

Recycled Pulp ◽

Fiber Wall ◽

Swelling Capacity ◽

Water Swelling

AbstractHornification is the loss of fiber wall swelling which is detrimental to subsequent recycling resulting from drying. It is known that dried fibers lose their conformability and swelling capacity. The effect of recycling treatment on the swelling ability of hardwood bleached kraft pulp fibers was determined. Modelling paper recycling, sheets were recycled using heat treatment (23°C, 60°C, 100°C). The results were compared with those for natural fibers from bleached kraft pulp. Swelling kinetics of sheets was measured by a modified method monitoring interactions of pulp with water. Swelling ability decreased during the recycling in comparison with never-recycled pulp at all temperatures. Recycling of sheets caused only small changes in the cupri-ethylene-diamine viscosity, however, the water retention value decreased considerably.

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Characterization of odorous compounds from bleached kraft pulp mill effluent

Water Science & Technology ◽

10.2166/wst.1995.0396 ◽

1995 ◽

Vol 31 (11) ◽

pp. 35-40 ◽

Cited By ~ 6

Author(s):

B. G. Brownlee ◽

S. L. Kenefick ◽

G. A. MacInnis ◽

S. E. Hrudey

Keyword(s):

Gas Chromatography ◽

Kraft Pulp ◽

Pulp Mill ◽

Dimethyl Disulfide ◽

Gas Chromatography Mass Spectrometry ◽

Pulp Mill Effluent ◽

Kraft Pulp Mill ◽

Bleached Kraft Pulp ◽

Methyl Phenyl Sulfide ◽

Library Spectrum

Odour compounds in extracts of bleached kraft pulp mill effluent (BKME) have been characterized by olfactory gas chromatography (OGC) and gas chromatography-mass spectrometry. A variety of sulfury odours was detected by OGC in addition to woody and pulp mill-like odours. Three sulfur compounds were identified by comparison of retention times and partial mass spectra with authentic standards: dimethyl disulfide, 3-methylthiophene and thioanisole (methyl phenyl sulfide). Typical concentrations in BKME were 1, 0.05, and 0.5 μg/l, respectively. Their odour intensity is relatively low and they were not detected by OGC. Dimethyl trisulfide was tentatively identified by comparison of its partial mass spectrum with a literature (library) spectrum. Its concentration in BKME was estimated at 0.5-2 μg/l. It corresponded to a skunky odour in the OGC profiles. Efforts to identify another odour peak, eluting just after 3-methylthiophene, with a pronounced alkyl sulfide odour were unsuccessful.

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Growth responses of periphyton and chironomids exposed to biologically treated bleached kraft pulp mill effluent

Water Science & Technology ◽

10.2166/wst.1997.0553 ◽

1997 ◽

Vol 35 (2-3) ◽

pp. 339-345 ◽

Cited By ~ 1

Author(s):

M. G. Dubé ◽

J. M. Culp

Keyword(s):

Kraft Pulp ◽

Pulp Mill ◽

Pulp Mill Effluent ◽

Growth Responses ◽

High Concentration ◽

Wood Extractives ◽

Kraft Pulp Mill ◽

Bleached Kraft Pulp ◽

Low Levels ◽

High Concentrations

Experiments were conducted in artificial streams to determine the effects of increasing concentrations of biologically treated bleached kraft pulp mill effluent (BKPME) on periphyton and chironomid growth in the Thompson River, British Columbia. Periphyton growth, as determined by increases in chlorophyll a, was significantly stimulated at all effluent concentrations tested (0.25%, 0.5%, 1.0%, 5.0% and, 10.0%). Chironomid growth (individual weight) was also significantly stimulated at low effluent concentrations (≤1.0%). At higher concentrations (5.0% and 10.0%), chironomid growth was inhibited relative to the 1.0% treatment streams. Increases in growth were attributed to the effects of nutrient and organic enrichment from BKPME. The effluent contained high concentrations of phosphorus and appears to be an important source of carbon for benthic insects grazing on the biofilm. In high concentration effluent streams, chironomid growth decreased despite low levels of typical pulp mill contaminants. This suggests that other compounds in the effluent, such as wood extractives, may be inhibiting chironomid growth. These results support findings of field monitoring studies conducted in the Thompson River where changes in periphyton and chironomid abundance occurred downstream of the bleached kraft pulp mill.

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