Tel: 011-4931-0051 | Mail:

Buscar Libro, Revista o Artículo...


Libros y Articulos relacionados con: I+I+D, Pulpa
1. Cómo conferir grosor al papel por vía química Este artículo de Sertec20 está enfocado a cómo conseguir aumentar el grosor del papel mediante productos químicos. Además, hace un repaso de las distintas formas de medición del grosor del papel. El Papel
Nº: 184
Fecha: Abril 2015
2. Nueva línea de fibra para disolver de Valmet en Sudáfrica El productor de papel y pasta Sappi produce pasta de madera para disolver de alta calidadden su planta sudafricana de Ngodwana desde 2013. El exclusivo concepto de línea de fibra para disolver de Valmet ha dado lugar a una solución flexible y sostenible. El Papel
Nº: 184
Fecha: Abril 2015
3. Sustainable raw material selection for pulp and paper using SAW multiple criteria decision making designIdentification of suitable specie and determination of suitable age of a tree are two important aspects related to selection of raw material for wood based and pulp and paper industry. General procedure adopted for addressing these problems includes the following steps: physicochemical characterization of raw material, morphological analysis of raw material, performing designed pulping and bleaching experiments, evaluation of pulp characteristics and mechanical strength properties of paper sheets. This study attempts to make these raw material selection efforts shorter and simpler using additive weighting (SAW) multiple criteria decision making (MCDM) approach taking into account only the proximate-chemical, physical and morphological features of raw materials. A total of four case studies related to selection of suitable specie of Eucalyptus and Leucaena; and selection of suitable age of Acacia and Leucaena species have been presented to demonstrate and validate the methodology of the proposed process. SAW method has been applied to the decision making unit comprising proximate-chemical, physical and morphological characteristics of these raw materials to rank them according to preference for pulping and papermaking. Results achieved in this research are in confirmation of those published in literature and reaveal that the SAW method is practical, feasible, and simple to apply for pulp and paper based raw material selection. IPPTA - The official jounal of the Indian Pulp and Paper Technical Association
Nº: 2701
Fecha: Enero 2015
4. Insight into the micro and nano aspects in bleaching of pulp Sin descripción. Paper Technology - PITA
Nº: 5602
Fecha: Junio 2015
5. Durapulp in principio fu una sediaUn viaggio lungo anni, costellato di incessanti ricerche e numerose, incoraggianti prove, ha portato alla produzione di un biocomposito che, conciliando la leggerezza e perculiarità ambientali della carta con la resistenza, versatilità della plastica, apre la strada a promettenti e svariate applicazioni, sia bi- che tridimensionali. Il primo impianto pilota per la fabbricazione di prototipi e articoli in DuraPulp è stato inaugurato lo scorso settembre, a Varberg, in prossimità dello stabilimento di Värö dove Södra produce la materia prima. Industria della carta
Nº: 5401
Fecha: Febrero 2016
6. The influence of strain rate and pulp properties on the stress relaxation of wet paper - modeling of relaxation The time-dependent stress (tension) relaxation behvior of wet paper plays a key role in web transfer from the press to the dryer section of a paper machine. In this study, three linear viscoelastic models were used to predict the short time range tension relaxation of wet paper. Over longer time periods, all three models gave relaxation moduli that were apparently linear on a logarithmic timeline. However, the results showed that the tension relaxation of wet paper had more than one characterisitc time constant, meaning that the initial tension relaxation phase had a different constant than the later phase or phases. In practical applications, the most relevant time range for runnability of the wet paper web is from milliseconds to a few seconds. The obtained results suggests that the strain rate and initial tension of the relaxation dictate the shape of the tension relaxation curve of wet paper: the higher the strain rate, the greater the tension loss during the first second of relaxation. The tension relaxation behavior of wet paper did not generally depend on pulp type, refining level of pulp, or solids content. However, there can be significant differences between furnishes and solids content in the amount of draw that leads to a sufficient web tension. The results indicated that the tension relaxation behavior of wet paper may be based on a general visco-elastic mechanism that is independent of fiber network properties but depends on the fiber wall material. The findings suggest that the redistribution mechanism of stresses in the wet fiber network has a high level of regularity. The Prony series was capable of predicting tension relaxation behavior of wet paper over a wide time range. Therefore, it can be a very useful simulation tool not only for wet webs, but for any viscoelastic material that shows stress (tension) relaxation. Tappi Journal
Nº: 1511
Fecha: Noviembre 2016
7. Effect of eucalyptus bark contamination during pulping of mixed southern hardwoods The used of eucalyptus as a partial replacement for mixed southern hardwoods can result in significant amounts of eucalyptus bark being incorporated into the chips going to the digester. When eucalyptus is first harvested, the bark peels off in large sheets, which will pass through chippers designed for southern hardwood. After being cut for more than about 4-6 weeks, the bark tightens onto the bole of the tree and again passes through chippers not designed for eucalyptus. As a result, significant quantities of eucalyptus bark could go to the digester. This study describes the effect of pulping eucalyptus bark in the laboratory. A series of control studies were performed on eucalyptus and mixed southern hardwood bark. The results show that incorporating bark into the cook results in increased kappa number, decreased pulp yield, and increased alkali consumption. If the percentage of applied active alkali is increased to counteract the increased alkali consumption, increased hexenuronic acid is generated. Tappi Journal
Nº: 1511
Fecha: Noviembre 2016
8. Press wetting as an enhanced wetting method for baled OCC material A procedure to mechanically force water into the bale sturctures of old corrugated container (OCC) material was studied and evaluated in low-consistency pulping studies. Two mechanical methods were used in the study: (1) roll pressing of sheets and (2) press wetting of bales. Mechanical pressing was first used in simple roll tests to evaluate nip pressure as an enhanced effect on wetting. Repeated press wetting treatments were found to increase water penetration into the sheets and appeared to lower wet strengths. A simple laboratory-scale bale pressing device was constructed and the effect of different parameters in wetting method was studied. We found that when a bale was pressed under water, multiple pressings were needed to get efficient press wetting. Increased temperature was found to increase water penetration inside the porous structure of linerboard. We also discovered that there must be a delay between relaxation and pressing to allow water to travel within a board and to wet all surfaces. The wetting procedure also evaluated the weight of water inside the bale. Results showed that the amount of water could be used as an indicator of the pulping kinetics and energy comsumption needed to disintegrate OCC. The enhanced method (i.e., hydraulic pressing) could provide efficient wetting on an industrial scale. With this method, a 30% savings in the energy consumption required in pulping unit operation is possible. Tappi Journal
Nº: 1501
Fecha: Enero 2016
10. Degradation of 2,4 - dichlorophenol by melamine amine celllulose - immobilized lacasses Epoxidized dialdehyde cellulose (EDC) was prepared and grafted with melamine to obtain melamine grafted epoxidized dialdehyde cellulose (EDC-melamine); the products were characterized by various methods and were used as carriers to immobilize lacasse. Results show EDC-melamine can immobilize laccase effectively and have higher enzymatic activity compared with EDC. Furthermore, the enzymatic activity of EDC-melamine was found to be as high as 865 U·mg-1, compared with 140U·mg-1 for EDC. The removal efficiency of 2.4-dichlorophenol (2,4-DCP) for EDC-melamine immobilized laccase was about 71.5% at 40ºC for 4 h at 10.0mg·L-1 and dosage of laccase = 0.2 g/L. The removal can remain greater than 63%, even after six cycles. Tappi Journal
Nº: 1610
Fecha: Octubre 2017