The formation of chromophores and leucochromophores during the manufacturing of thermomechanical pulp (TMP) has been investigated. As analytical tools, advanced UV-VIS and NMR spectroscopy have been used. With the exception of some pilot plant scale refining experiments, that were carried out at Valmet Fibertech (Sundsvall), the work has been conducted at the Royal Institute of Technology (Stoc...

Fiber development in pulp refining can be characterized by three parameters: number of impacts on pulp, N; energy per impact, I, and bar force fibers, F. These parameters enable comparisons radically different conditions; determination intensity for hardwoods softwoods; assessment effect width fiber shortening; predictions tensile strength increases.

Enzymatic treatment of different sulphite pulps with cellulases has been studied in this work. Endoglucanases were shown to beneficially alter the properties of both paper-grade and dissolving-grade pulps. In the case of the paper-grade pulp, the treatment with endoglucanase resulted in a considerable reduction of the pulp refining time without decrease in strength properties. While for the dis...

Kraft pulp produced from juvenile and mature wood from thirty-two-yearold Corymbia citriodora trees was evaluated. The stem was subdivided into regions of juvenile and mature wood, and then it was transformed into chips. These materials were then cooked in the Laboratory of Pulp and Paper at São Paulo State University (UNESP, Botucatu, SP, Brazil) and the physico-mechanical properties of the pu...

Primary refined coarse softwood thermomechanical pulp was treated with alkaline peroxide prior to low-consistency (LC) refining. The effects of the pre-treatments on pulp quality, refinability, and electrical energy consumption were assessed. Four pre-treatments were conducted with alkali charges of 2.5 and 6% and peroxide charges of 3 and 4%. The pulps were refined to specific energies up to 6...

RTSTM and TMP mill case studies were conducted, utilizing FiberMaxXTM, FiberMaxX-EXTM, and VPZTM refiner plate patterns, to reduce refining energy, improve pulp quality and increase production rates depending upon the specific application. In the studies the refiner plate designs selected provided from 200 to 280 kwh/odmt energy reduction. In addition pulp strengths were either maintained or im...

To confer hydrophobic properties to Kraft pulp, an environmentally friendly process using laccase and lauryl gallate (LG) was developed. This treatment resulted in paper with very high water-barrier properties. The loss of hydrophobicity after acetone Soxhlet extraction highlighted the key role of adsorption phenomena on the introduction of pulp properties. GC-FID analysis of the extraction sup...