scholarly journals Structural Characterisation of Kraft Pulp Fibres and Their Nanofibrillated Materials for Biodegradable Composite Applications

10.5772/21580 ◽  
2011 ◽  
Author(s):  
Gary Chinga-Carrasco ◽  
Arttu Miettinen ◽  
Cris L. Luengo Hendriks ◽  
E. Kristofer ◽  
Markku Kataj
Keyword(s):  
Kraft Pulp ◽  
Structural Characterisation ◽  
Biodegradable Composite ◽  
Pulp Fibres

scholarly journals Modification of softwood kraft pulp fibres using hydrogen peroxide at acidic conditions

Cellulose ◽  
2020 ◽  
Vol 27 (12) ◽  
pp. 7191-7202
Author(s):  
Axel Martinsson ◽  
Merima Hasani ◽  
Antje Potthast ◽  
Hans Theliander
Keyword(s):  
Hydrogen Peroxide ◽  
Residence Time ◽  
Kraft Pulp ◽  
Hydroxyl Groups ◽  
Carbonyl Groups ◽  
Wet Strength ◽  
Covalent Bonds ◽  
Softwood Kraft Pulp ◽  
Pulp Fibres ◽  
Acidic Conditions

Abstract The aim of this work was to provide softwood kraft pulp fibres with new functionalities by the introduction of carbonyl groups. Carbonyl groups are known to affect properties such as wet strength through the formation of covalent bonds, i.e. hemiacetals. The method developed involves oxidation using hydrogen peroxide at mildly acidic conditions. It was found that the carbonyl group content increased with both increasing temperature and residence time when oxidized at acidic conditions. The number of carboxylic groups, however, remained approximately constant. There was virtually no increase in carbonyl groups when oxidation was performed at alkaline conditions. The maximum increase in carbonyl groups was found at a residence time of 90 min, a reaction temperature of 85 °C and a pH of 4. These conditions resulted in an increase in carbonyl groups from 30 to 122 µmol/g. When formed into a sheet, the pulp oxidized at acidic conditions proved to maintain its structural integrity at aqueous conditions. This indicates the formation of hemiacetal bonds between the introduced carbonyl groups and the hydroxyl groups on the carbohydrate chains. Thus, a possible application for the method could be fibre modification during the final bleaching stage of softwood kraft pulp, where the wet strength of the pulp could be increased.

scholarly journals Chemical composition and fiber properties of fast-growing species in Latvia and its potential for forest bioindustry

2017 ◽  
Vol 66 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Inese Sable ◽  
Uldis Grinfelds ◽  
Laura Vikele ◽  
Linda Rozenberga ◽  
Dagnija Lazdina ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Kraft Pulp ◽  
Lignin Content ◽  
Lodgepole Pine ◽  
Pulp Yield ◽  
Fine Content ◽  
Fast Growing ◽  
Pulp Fibres ◽  
Global Energy Supply ◽  
Fast Growing Species

AbstractBioenergy, including energy from wood, currently provides about 9–13% of the total global energy supply. Every fibre of fast-growing wood has a value for its potential use as a material in both pulp and paper and wood chemical industries. The aim of this study was to assess the chemical composition and fibre’s properties of fast-growing species in Latvia – aspen, hybrid aspen, lodgepole pine, poplar and willow. Results showed a variation of cellulose, lignin, extractives and ash contents among the species. Kraft pulp yield and amount of residual lignin were measured and properties of pulp fibres determined. Form factor and fine content in pulp were measured. Poplar and aspen wood had the highest content of cellulose, while lodgepole pine had the highest lignin content in wood and the longest kraft pulp fibres. Willow had 20% of fines in pulp. Individual results suggest the most suitable application of each species.

Scanning probe microscopy of pine and birch kraft pulp fibres

Polymer ◽  
2000 ◽  
Vol 41 (6) ◽  
pp. 2121-2126 ◽  
Author(s):  
J Simola ◽  
P Malkavaara ◽  
R Alén ◽  
J Peltonen
Keyword(s):  
Scanning Probe Microscopy ◽  
Kraft Pulp ◽  
Scanning Probe ◽  
Probe Microscopy ◽  
Pulp Fibres ◽  
Birch Kraft Pulp

Ultrastructural changes in a holocellulose pulp revealed by enzymes, thermoporosimetry and atomic force microscopy

Holzforschung ◽  
2005 ◽  
Vol 59 (6) ◽  
pp. 589-597 ◽  
Author(s):  
Jesper Fahlén ◽  
Lennart Salmén
Keyword(s):  
Atomic Force Microscopy ◽  
Kraft Pulp ◽  
Enzymatic Treatment ◽  
Ultrastructural Changes ◽  
Cellulose Fibril ◽  
Force Microscopy ◽  
Fibre Wall ◽  
Atomic Force ◽  
Pulp Fibres ◽  
Fibril Aggregates

Abstract To increase our knowledge of the ultrastructure within softwood fibres, enzymatic treatment, thermoporosimetry, light microscopy, and atomic force microscopy with image analysis were used to investigate the structure of holocellulose softwood pulp fibres. The size of the average cellulose fibril aggregates and the width of pore and matrix lamellae were found to be uniform across the secondary cell-wall layer in the transverse direction of the wood fibre wall. In holocellulose, these dimensions were very similar to those in the native wood, whereas in kraft pulp the cellulose fibril aggregates were larger and the pore and matrix lamellae broader. These differences between holocellulose and kraft pulp fibres suggest that a high temperature is needed for cellulose fibril aggregation to occur. Neither refining nor drying of the holocellulose pulp changed the cellulose fibril aggregate size. Upon drying and enzymatic treatment, a small decrease in the pore and matrix lamella width was evident throughout the fibre wall. This indicated not only uniform distribution of pores throughout the fibre wall, but also enzymatic accessibility to the entire fibre wall. The holocellulose pulp had a somewhat larger pore volume than the kraft pulp. Refining of the holocellulose pulp led to pore closure, probably due to increased mobility of the fibre wall. The enzymatic treatment revealed that during hydrolysis of one hemicellulose, part of the other was also dissolved, indicating that the two hemicelluloses are to some extent linked to each other in the structure.

Bulk and surface composition of ECF bleached hardwood kraft pulp fibres

2004 ◽  
Vol 19 (4) ◽  
pp. 513-520 ◽  
Author(s):  
Carlos Pascoal Neto ◽  
Armando J.D. Silvestre ◽  
Dmitry V. Evtuguin ◽  
Carmen S.R. Freire ◽  
Paula C.R. Pinto ◽  
...  
Keyword(s):  
Kraft Pulp ◽  
Surface Composition ◽  
Pulp Fibres

scholarly journals Canadian Pulp and Paper in World Trade

1978 ◽  
Vol 54 (3) ◽  
pp. 147-151
Author(s):  
D. B. Cooke
Keyword(s):  
Kraft Pulp ◽  
Paper Industry ◽  
Pulp And Paper ◽  
Forest Resource ◽  
Pulp Industry ◽  
Bleached Kraft Pulp ◽  
Self Sufficiency ◽  
Excellent Growth ◽  
World Demand ◽  
Pulp Fibres

Canada still commands a major position in two key world pulp and paper products which come from our softwood forest resource — newsprint and woodpulp. In 1977 Canada produced 40% of the newsprint and 30% of the softwood bleached kraft used in the free world. Fine papers, linerboard and tissue grades of paper are made chiefly for the domestic market and are all tariff protected.After 30 years of excellent growth, the future prospects for the Canadian pulp and paper industry are clouded by: slower world demand for paper and board, increased self-sufficiency for newsprint and pulp in many of Canada's key markets, continuing trends to substitution of cheaper pulp fibres for the more expensive softwood bleached kraft pulp, the cornerstone of Canada's pulp industry.

scholarly journals Papermaking Using Willow (Salix dasiclados) as a Hardwood Source – A Handsheet and Pilot Paper Machine Study

2019 ◽  
pp. 1-16 ◽  
Author(s):  
Klaus Dölle
Keyword(s):  
Kraft Pulp ◽  
Paper Machine ◽  
Paper Production ◽  
Pulp Fibre ◽  
Recycled Pulp ◽  
Tear Index ◽  
Pulp Fibres ◽  
Hardwood Pulp ◽  
Recycled Fibres

This laboratory handsheet and Fourdrinier pilot paper machine study examine the suitability of willow as a commercial hardwood pulp replacement including utilizing recycled pulp for paper production. The hand sheet study contains 16 different and the pilot paper machine study eight different furnish mixtures. For both studies, the base sheet consists of a 40% softwood and 60% hardwood commercial pulp mixture, followed by replacing the hardwood with bleached willow Kraft pulp. Deinked pulp, as recycled fibres, at 5% increments up to 100% for the handsheet study and at 10%, 20%, 30%, 50%, 70% and 90% for the pilot paper machine study is added to the base pulp mixture. Both the handsheet and the FPPM study revealed that willow Kraft pulp can replace commercial hardwood pulp fibres.  Basis weight, calliper and stiffness as related properties showed comparable results for the handsheet study. Willow Kraft fibres tend to be bulkier and denser than the used hardwood fibres. Tensile and tear index show comparable properties for the handsheet and pilot paper machine study, except for the 50%, 70% and 90% DIP containing paper sheets. Porosity values for the hansheet study showed lower results than the base sheet, whereas the FPPM study showed higher results except for the 70% and 90% DIP containing handsheet. Comparable results are shown for opacity. Brightness levels were significantly lower due to the lower brightness of the manufactured willow Kraft and deinked pulp fibre furnish. Despite the opportunity of replacing commercial hardwood with willow, more research needed to optimize willow into pulp fibres and preparation of the fibres for papermaking.

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