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The use of polyelec...
Abstract
Ämnesord
Stäng
- In this work the application of polyelectrolyte complexes (PEC) to different pulps, to improve the strength of papers produced from them, is compared with conventional pulp beating. The pulps chosen for the investigation were a fully bleached chemical hardwood pulp (HBK), a fully bleached chemical softwood pulp (SBK), and a peroxide-bleached chemithermomechanical pulp (BCTMP). The polyelectrolytes used were a polyamideamine epichlorohydrine condensate (PAE), traditionally used as a wet-strength additive, and carboxymethylcellulose. Since the prepared complexes had an anionic charge, they could only be used after fibre pre-treatment with the cationic PAE. Results indicate that the addition of 2% PAE and 2% PEC can improve all the measured tensile strength properties of the sheets as much as is commonly achieved by mechanically beating the pulps. In fact, for the chemical pulps, PEC addition at the chosen level produced better results than did traditional beating, since the improved tensile index and tensile energy absorption could be achieved without any significant deterioration in the light scattering coefficient of the papers produced. However, with the BCTMP a significant decrease in light scattering could be detected, especially following the addition of PEC. Adding the chemicals (especially the PEC) increased the sheet density and this together with the increase in the tensile stiffness, following chemical addition, resulted in a constant bending stiffness of the sheets. However, based on the results it can be suggested that a combination of unbeaten HBK and BCTMP treated with PAE and PEC can be used to produce a strong paper with a high bending stiffness.
Ämnesord
- TEKNIK OCH TEKNOLOGIER -- Materialteknik -- Pappers-, massa- och fiberteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Materials Engineering -- Paper, Pulp and Fiber Technology (hsv//eng)
- TEKNIK OCH TEKNOLOGIER -- Kemiteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Chemical Engineering (hsv//eng)
Nyckelord
- adsorption
- beating
- polyelectrolytes
- polyelectrolyte complexes
- tensile properties
- surface modification
- wood fibers
- topochemical modification
- carboxymethyl cellulose
- dry-strength
- part i
- wet
- performance
- attachment
- Cellulose and paper engineering
- Cellulosa- och pappersteknik
- Chemical engineering
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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