Results 111 to 120 of about 289 (151)

Variation of Phenolic Hydroxyl Contents in Unbleached Kraft Pulps

Holzforschung, 1995
The content of phenolic hydroxyl groups in the unbleached kraft pulp residual lignin was determined in situ by periodate oxidation method. This functional group has been shown to increase steadily with the extent of kraft delignification throughout the entire pulping process.
Yuan-Zong Lai
exaly   +2 more sources

Characterisation of fines from unbleached kraft pulps and their impact on sheet properties

Holzforschung, 2008
Abstract Fines are an essential component in the papermaking process because they have a profound influence on the behaviour of the wet web and on the mechanical properties of the final sheet. Primary fines are present in the pulp prior to refining, and secondary fines are produced during refining.
Marie Backstrom
exaly   +2 more sources

Characterization of Unbleached Kraft Pulps by Enzymatic Treatment, Potentiometric Titration and Polyelectrolyte Adsorption

Holzforschung, 1996
The surface properties of unbleached softwood (Pinus sylvestris) and hardwood (Betula verrucosa) kraft pulps were modified by treating the fibre surfaces with specific xylanase and mannanase (Trichoderma reesei). The amounts and accessibilities of surface carboxyl groups in untreated and enzyme-treated fibres were analyzed using adsorption of cationic ...
Janne Laine, Per Stenius, Johanna Buchert   +2 more
exaly   +2 more sources

The influence of pulping and washing conditions on the properties of Eucalyptus grandis unbleached kraft pulps treated with chelants

Bioresource Technology, 2010
The influence of different addition points of a chelating agent and a counter-ion exchange on the properties of Eucalyptus grandis unbleached kraft pulps is studied. Seven pulps were considered: two laboratory kraft pulps with or without the inclusion of the chelant DTPMPA (diethylene triamine penta (methylene phosphonic acid)), a mill kraft pulp and ...
Maria Cristina Area, M G V S Carvalho
exaly   +3 more sources

Characterization of Residual Lignins Isolated from Unbleached and Semibleached Softwood Kraft Pulps

Journal of Wood Chemistry and Technology, 1987
Abstract Residual lignins in an unbleached and a semibleached softwood (Pinus taeda L.) kraft pulp were isolated by enzymatic hydrolysis of polysaccharides in the pulps. After purification, the residual lignins were characterized. A dissolved lignin was also isolated from the alkaline extraction spent liquor by acidification and characterized.
Hou-Min Chang
exaly   +2 more sources

Effect of electrolyte concentration and pH on the beatability of unbleached kraft pulps

Nordic Pulp and Paper Research Journal, 2000
Marie Backstrom
exaly   +2 more sources

Residual Lignin in Unbleached Kraft Pulp. Part 2. -Analysis of Unbleached Kraft Pulp by New Permethylation Method-

Journal of Wood Chemistry and Technology, 1987
Abstract Unbleached kraft pulp (UKP), its residue after extraction with concentrated alkali (α-UKP), bleached kraft pulp prepared from UKP (BKP) and its residue after extraction with concentrated alkali (α-BKP) were permethylated with powdered NaOH and CH3I in their SO2-diethylamine (DEA)-dimethylsufoxide (DMSO) solutions.
Akira Isogai, Atsushi Ishizu, Junzo Nakano   +2 more
openaire   +1 more source

Surface characterization of unbleached kraft pulps by means of ESCA

Cellulose, 1994
The effect of digestion conditions (amount of effective alkali, digestion time) on the surface compositions of unbleached softwood (Pinus sylvestris) kraft pulp has been investigated by electron spectroscopy for chemical analysis (ESCA). The quantities monitored were the angular dependence of the total O/C ratio, the relative amounts of carbons in ...
Janne Laine, Per Stenius, Gilbert Carlsson, G�ran Str�m   +3 more
openaire   +1 more source

Xylanase-Resistant Xylan In Unbleached Kraft Pulp

Journal of Wood Chemistry and Technology, 1996
ABSTRACT A water-soluble chromophoric xylanase-resitant xylan fraction (LF-D) was separated from a hardwood unbleached kraft pulp (UKP) after hydrolysis with a cellulase/ xylanase-membrane bioreactor. LF-D contained over 70% unremovable inorganic atoms including Si, Na, and S, together with a β-1,4- linked xylan.
Takashi Watanabe, Keigo Mikame, Yoichi Honda, Masaaki Kuwahara   +3 more
openaire   +1 more source

Delignification of an unbleached hardwood kraft pulp by Phanerochaete chrysosporium

Applied Microbiology and Biotechnology, 1987
Culture conditions affecting lignin degradation of an unbleached hardwood kraft pulp by Phanerochaete chrysosporium have been examined. Optimum pH and temperature for lignin degradation (about 33%) were 3.5 and 38°C, respectively. Optimum fungal growth was at a pH of 4.5 and a temperature of around 32°C.
Ai V. Tran, Robert P. Chambers
openaire   +1 more source