Search

Windmill palm fiber (WPF) is an abundant source of cellulose fiber that can be used in textile manufacturing. In this study, acid-alkali palm fiber and acid-alkali-enzyme palm fiber were prepared to create blended yarns. The morphology, chemical composition, physical structural parameters, and tensile properties of the WPF samples and yarns were studied. The results indicated that both the acid-alkali and acid-alkali-enzyme treatments can be used as degumming methods to prepare windmill palm textile-grade long fibers with spinning ability. After chemical treatment, the cellulose content of WPF increased to more than 60%, up from 34%. However, the line densities of the acid-alkali and acid-alkali-enzyme textile-grade long fibers decreased to 5.29 ± 1.00 tex and 4.52 ± 0.82 tex, respectively. For the enzyme-treated fiber, a stratification phenomenon of the fiber cell walls and a decrease in the modulus were observed. The palm/cotton yarn had a high tensile strength and strip uniformity. [ABSTRACT FROM AUTHOR]

Effects of cellulase enzymatic treatment followed by mechanical beating were evaluated relative to the properties of cellulase-derived tissue pulps and handsheets. When different cellulase concentrations (0.0012 FPU/g, 0.0018 FPU/g, and 0.0024 FPU/g) of oven dried pulp (a 65/35 w/w ratio of beech to eucalyptus) were used for tissue production, a slight deterioration of the morphological characteristics was observed. Thus, a possibility of controlling the changes in the degree of polymerization of cellulose, as well as the fiber properties (in particular the length and coarseness) appeared. With an increased treatment time and enzyme concentration, these effects increased. The enzyme activity did not affect the apparent density of the paper, but the porosity drastically increased. The zero-span strength of the enzymatically treated pulps decreased with an increase in treatment time and amount of cellulase. However, mechanical beating improved the bonding between the cellulase fibers, which helped prevent the eventual decrease in mechanical properties of the handsheets. With the use of cellulase, the proposed moderate changes to fiber structure were achieved, giving the possibility of predicting and controlling the properties of tissue paper. [ABSTRACT FROM AUTHOR]

This study aimed to determine the influence of prehydrolysis of wood chips on the kraft pulping of Populus x euramericana. Optimum cooking conditions were determined by evaluating different alkali concentrations and cooking periods. Xylanase was used to hydrolyze chips before cooking. Prehydrolysis process increased the yield and viscosity of pulp. Consequently, the mechanical properties of paper changed remarkably. In contrast, the optical properties of the unbleached kraft pulp declined due to lignin content. [ABSTRACT FROM AUTHOR]

Cellulose is the most abundant natural polymer on earth. As the market and the public demands more and more natural products, cellulose and its derivatives are becoming increasingly more attractive. The production of dissolving pulp, which is the main feedstock for cellulose-related products, has been growing over the past decade, while the technologies for manufacturing these pulps have also been advanced. In this literature review, the production and consumption of dissolving pulp are analyzed with a focus on the Chinese market. The manufacturing processes, including raw materials, pulping methods, pulp bleaching, and posttreatments are discussed. [ABSTRACT FROM AUTHOR]

In this study it was shown that the enzymatic removal of xylan from ECFbleached birch kraft pulp enhances the water removal from the pulp, especially in the late stages of pulp drying. The effect of xylanase treatments on dewatering was clarified by using a moving belt former (MBF), a press simulator (MTS), and an IR-drying equipment, to simulate and to measure dewatering properties on wire, press and drying sections of a paper machine. The xylanase treatment slightly increased the pulp freeness indicating improved pulp drainage properties. At the moving belt former, however, no significant changes that would indicate enhanced dewatering in forming were observed. The xylanase treatments slightly enhanced the dewatering in wet pressing and furthermore, at the thermal drying the xylanase treatment had a positive effect on the dry solid content (DSC) development, and time to reach the 95% dry solids content was reduced by up to 15%. This was also confirmed by the decrease in the fiber saturation point (FSP) values and the amount of bulk water. Our results indicate that the xylanase treatment affected the water-binding xylan in the fiber cell wall, yielding enhanced dewatering properties, without deteriorating the pulp and paper properties. [ABSTRACT FROM AUTHOR]