The Influence of Beating of Pulp on Fiber Length and Fiber Length Distribution

1. Introduction Recent studies and researchers assume that certain relationships exist between different properties of pulp - such as between bulk, tearing resistance, bursting strength, tensile strength, freeness, and fiber length index. It has been found furthermore that such relations are different for different types of pulp and that some may even vary from pulp to pulp of the same type

Preliminary Investigation on Bamboo Pulping

A preliminary investigation on bamboo pulping by Semi-Keebra process reveals that a higher pulp yield than that obtained by most of the known methods of pulping bamboo can be attained by Semi-Keebra process.* The chemical requirement for pulping is lower than the conventional processes and the spent liquor also contains a higher per cent of solids. The pulp obtained by Semi-Keebra pulp would also require a considerable lesser time for obtaining the desired freeness value, resulting in lower power consumption for stock preparation, than that for the conventional sulphate bamboo pulp of bleachable grade. A comparison of the various hand-sheet properties of the two pulps show that all properties other than density and breaking length are, however, lower in the case of Semi-Keebra bamboo pulp. It is, however, hoped that further investigation on optimum condition of Semi-Keebra process for bamboo pulping would show some further improvement in the strength properties

Office paper recyclability: first recycling

Paper recyclability implies in the paper capacity to be recycled maintaining its properties to the maximum. Four commercial papers from Argentina and Brazil were studied, including three eucalyptus kraft (A, B, C) and one sugar cane bagasse soda-AQ (D), all with different bleaching processes. Their physical and chemical properties and a first laboratory recycling were evaluated. A refining of the pulp with a PFI mill, applying two energy levels at two different intensities - measured by number of revolutions and load - was accomplished to reach the same °SR (between 30 and 40, approximately). The refining energy and the yield were registered in each case. The properties of laboratory handsheets, and the aging to 24, 48, 72 and 144 hours were evaluated. The statistical analysis of the results indicates that the properties of the initial eucalyptus papers were similar, whereas they were generally inferior in the case of the bagasse paper. The bagasse and eucalyptus papers presented similar initial whiteness, but the first one had a higher reversion than the others. Once repulped, the eucalyptus papers A, B and C required, respectively, 4, 7 and 10 times greater energy than D, to obtain the same °SR. In all cases, the required energy to achieve the same °SR is slightly greater with the smaller refining intensity. The physical properties of the handsheets from the first recycle of paper D were, in general, lower. Among eucalyptus papers, B showed a slightly higher resistance and C, a slightly lower one. The mechanical properties of pulp sheets A, and D to a lesser extension, were more affected by the refining intensity than the rest, indicating a higher sensitivity of the fibers. The whiteness of the sheets of pulp B is lower than the rest. Opacity and light scattering coefficient of the sheets of pulp C were much higher than those of the other pulps.Fil: Benitez, Julieta Beatriz. Universidad Nacional de Misiones; ArgentinaFil: Koga, Mariza E. T.. Instituto de Pesquisas Tecnológicas de São Paulo (ipt); BrasilFil: Otero D'Almeida, Maria L.. Instituto de Pesquisas Tecnológicas de São Paulo (ipt); BrasilFil: Felissia, Fernando Esteban. Universidad Nacional de Misiones; ArgentinaFil: Park, Song W.. Escola Politecnica, Universidad de Sao Paulo (usp); BrasilFil: Area, Maria Cristina. Universidad Nacional de Misiones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Substituting Wood with Nonwood Fibers in Papermaking: A Win-Win Solution for Bangladesh

Bangladesh is facing an acute shortage of fibrous raw materials for the production of pulp and paper. On the other hand, the demand for paper and paper products is increasing day by day. This study reviews the availability and suitability of nonwood raw materials for pulp production in Bangladesh. It shows that Bangladesh has a huge amount of unused jute fiber, which is highly suitable for papermaking in Bangladesh. Other agricultural wastes like rice straw, dhaincha, golpata fronds, cotton stalks, corn stalks, and kash are also available and may be used for some pulp production. Given the different properties of these different nonwood fibers, jute pulp can be used as a reinforcing agent with other nonwood pulps for the production of high quality paper in Bangladesh.Bangladesh, natural fibers, jute, paper making, pulp

Papermaking properties of various pulps used for printing paper production

Papermaking properties of recycled pulp obtained from office paper, thermomechanical and chemithermomechanical pulp were investigated. The optimal refining parameters of recycled pulp and chemithermomechanical pulp such as refining time, rotational disk speed and refiner disk gap, allowing to increase their papermaking properties, were determined. It was found that recycled pulp exhibits the greatest efficiency (among the pulps under investigation) of chemical pulps replacing in the furnish composition of offset printing paper

Used papermaking properties of pulp the compositions of the printing paper

The article presents a study of two kinds of papermaking pulp properties, that is thermomechanical and chemi-thermomechanical. Optimal parameters ofgrinding chemical-thermo-mechanical pulp were defined. Influence of pulp on the structural, mechanical and optical properties of paper samples was studied for offset printing. It has been established that the use of wood pulp in composition does not adversely affect on the structural, mechanical, optical and printing properties of paper

Effects of potassium/sodium fertilization and water availability on wood properties of Eucalyptus grandis trees

In Brazil. most Eucalyptus plantations are located in regions experiencing periods of water shortage where fertilizers such as potassium (K) are intensively used to achieve high productivity. Recently. sodium(, a) has also been considered a potential nutrient. As well as tree growth, wood properties are also an important factor to consider in order to measure the impacts of silvicultural practices and water deficit on forest productivity, since they are determinants for quality and yield of pulp and paper. In a split-plot experimental design with 4-year-old Eucalyptus grandis trees, located in Sao Paulo State, Brazil, we evaluate the effects or K and Na supply compared with a control treatment under two water supply regimes (37% throughfall reduction versus no throughfall reduction) on stem volume, heartwood proportion. basic density, fiber, and vessel properties. K and Na fertilization increased stem volume 2. 7 and 1.9 fold. respectively, with a nonsignificant effect of 37% throughfall reduction. Na fertilization was more detrimental to wood properties that K fertilization, affecting heartwood proportion, basic density, and fiber wall thickness. K fertilization affected only heartwood proportion and basic density. The 37% throughfall reduction only affected wood basic density. increasing it. Effects of fertilization treatments did not change regardless changes in water supply.Despite the detrimental effects of fertilizers (stronger with Na supply) in wood properties there is a large beneficial effect on stem volume (stronger with K supply), even under a water availability reduction, that would be compensates the loss of wood quality for pulp and paper production

Lignocellulosic Recycled Materials to Design Molded Products: Optimization of Physical and Mechanical Properties

The object is to contribute to the reduction of environmental pollution, by reusing a fraction of urban solid waste, forestry and agroindustrial waste: newspaper (ONP), office paper (OWP), corrugated cardboard (OCC), pine sawdust, eucalyptus sawdust and sugar cane bagasse as raw material to design biocontainers suitable for growing plants, by applying pulp molding technology. The purpose is to evaluate the effects of the combination of these lignocellulosic materials on the physical-mechanical properties and optimize responses in order to select an ideal mixture on basis the product?s necessities. An experimental design of type mixture of extreme vertices was followed, considering secondary fibers as base material, in a 0-100% proportion, and pine sawdust, eucalyptus sawdust and bagasse fibers as reinforcement, in a 0-40% proportion. An experimental matrix by each reinforcing material was proposed. Properties were evaluated: density, tensile, bursting, tearing, compression, stiffness, wet tensile, permeability and water retention, testing handsheets weighing 150 g/m2. Responses were optimized using a statistical program. It was found that OWP pulps increase strength properties; OCC pulps increases tear and wet tensile; ONP pulps increase stiffness and reinforcement materials increase permeability. Factors that allow reaching the objectives are a mixture of pulp OWP/OCC in a 50/50 proportion.Fil: Aguerre, Yanina Susel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Gavazzo, Graciela Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; Argentin

An Analysis of the Wash and Flotation Deinking Processes

The purpose of this paper is to obtain data, so that we may compare the ability of Floatation vs. Wash deinking to produce a paper of equal standards as the original unprinted base-stock. It was determined that both flotation and wash deinked stock with the addition of 40% fresh pulp can produce a paper of equal physical and optical properties as the unprinted stock from which it was made. Floatation deinked stock was found have a higher materials cost, however, it displayed better strength and opacity properties than wash deinked stock. The difference is thought to result from a large fines loss in the wash deinking process