Wood consists mainly of three types of polymers; cellulose, hemi cellulose and lignin. Lignin is formed in nature through enzymatic initiated oxidative coupling of three different kinds of phenyl propane units. These form by various carbon-carbon and carbon-oxygen bonds, an amorphous three-dimensional polymer. As chemical pulp is produced, lignin is degraded and dissolved into pulping liquors. ...

Eucalyptus globulus represents one of the most suited fibre sources for the production of a wide range of high quality papers and high-purity dissolving pulps. The optimization of kraft pulping covering both continuous and batch processes demands kinetic models suitable for advanced control and offline optimization of the cooking operation. Quite recently, an improved kinetic model structure fo...

The aim of the present work was to find a suitable Kraft cooking process for olive tree pruning (OTP), in order to produce pulp of kappa number about 17. The Kraft pulp produced under optimized conditions showed a viscosity of 31.5 mPa·s and good physical, mechanical, and optical properties, which are suitable for paper production. The physical-mechanical and optical properties were measured be...

in this research, effect of using hornbeam and beech branch woods in admixture with birch stem wood on their cmp pulp properties. using percentage of branch woods, with 20% constant content for birch stem wood, were 0, 16, 40, 56 and 80 in final mixture of hardwoods. the results indicated that cooking time, to reach 85% yield and under same cooking condition, and also refining quantity, to reac...

Chemical and enzymatic modifications intended to improve the reactivity of dissolving pulp rapidly decrease its yield. In this study, a beating posttreatment intended to increase the reactivity of bamboo dissolving pulp was investigated. Beating post-treatment can create microfibrils on the surface of fibers. The reactivity of unrefined bamboo dissolving pulp prepared via pre-hydrolysis and a s...

in this research, the chemimechanical pulps (cmp) with different yields were prepared by using the mixtures of constant raw materials comprising iranian hardwood species such as hornbeam (44%), poplar (31%), maple (15%) and salix (10%). this research was aiming to study cmp pulp properties variations in yields lower than standard limit (85%). four different yields (84, 80, 73 and 67%) were achi...

This review analyses the advances of pretreatment with sulfide-containing liquors to modify kraft pulping. In the past several decades, modified kraft pulping has advanced rapidly, based on the principle that high sulfide content at the first stage of cooking would improve both pulp quality and the selectivity of delignification. Pretreatment of wood chips with sulfide-containing liquors (i.e.b...

Winter squash "type butternut" is harvested in physiological ripening for better commercial distribution, when sensory and/or nutritional quality is not optimum for consumption. The objective of this study was to quantify the content of α-carotene, β-carotene, color and dry matter in the pulp of raw and microwave-cooked winter squash "type butternut" (variety CosmoF1) in three states of commerc...