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...

EXPERIMENTAL A softwood (mainly spruce) bleached kraft pulp (SWBKP), and a hardwood (eucalyptus) bleached kraft pulp (HWBKP) were refined in a PFI mill to 470 and 490 ml CSF freeness, respectively. Three grades of commercial aspen high-yield pulp (325/85, 325/83, 250/80) were obtained from Tembec Inc., without further refining treatment. The properties of the pulp samples are listed in Table I....

Studies on strength delivery and related fields have so far concentrated on finding the locations in the mill where fibres are damaged and what the damages consist of. However, fibres will invariably encounter mechanical stresses along the fibreline and in this thesis a new concept is introduced; the vulnerability of fibres to mechanical treatment. It is hypothesised that fibres with different ...

We studied somatosensory evoked fields elicited by mechanical vs. electrical stimuli to index finger of healthy subjects. Mechanical stimulation was index pulp compression and decompression by using non-magnetic mechanical stimulator. Electrical stimulation was three times of sensory threshold and delivered to index pulp by using ball-shaped electrodes. Mechanical/electrical-stimuli evoked cont...

4-META/MMA-TBB resin has clinically favorable mechanical and bonding properties and undergoes unique, moisture-insensitive polymerization. To explore the potential usefulness of 4-META/ MMA-TBB resin as a pulp capping material, this study examined its biological and biochemical properties. Rat dental pulp cells were cultured on 4-META/MMA-TBB resin, resin-modified glassionomer (RMGI) cement, an...

Direct pulp capping (DPC) is defined as the treatment of a mechanical or traumatic vital pulp exposure by sealing the pulpal wound with a biomaterial placed directly on exposed pulp to facilitate formation of reparative dentin and maintenance of the vitality of pulp. 1 Calcium hydroxide has been the gold standard for this purpose. The alkalinity of calcium hydroxide causes superficial necrosis ...

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...

Freshwater algal biomass and orange and lemon peels were assessed as tissue paper pulp supplements. Cellulose and hemicellulose contents of algal biomass were 7.1% and 16.3%, respectively, whereas for citrus peels cellulose content ranged from 12.7% to 13.6% and hemicellulose from 5.3% to 6.1%. For all materials, lignin and ash content was 2% or lower, rendering them suitable for use as paper p...

Cellulose nanofibrils were prepared by mechanical fibrillation of never-dried beech pulp and bacterial cellulose. To facilitate the separation of individual fibrils, one part of the wood pulp was surface-carboxylated by a catalytic oxidation using (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) as a catalyst. After fibrillation by a high pressure homogenizer, the obtained aqueous fibril dispers...

The objective of this study was to evaluate different pretreatment methods prior to oxygen delignification on extractives removal and O-delignification selectivity. Four different pretreatment methods were used including ultrasonic treatment, hot water soaking, soda addition-preheating, and applying a high-shear mechanical pretretament. Acacia mangium and mixed hardwood (MHW) kraft pulps were u...