Search Results

You are looking at 1 - 10 of 557 items :

  • "Thermomechanical pulps" x
Clear All

long-term performance of the fiber-cement composites (Tonoli et al. 2010b; Muguet et al. 2012). The refining of thermomechanical pulping (TMP) can be thought to involve two main phases: (1) defibration or fiber separation, where the wood matrix is softened, and the separation of fiber bunches and single fibers begins, and (2) fiber development, where the wood fibers start to be disintegrated with the main effects, such as delamination and internal fibrillation (Fernando and Daniel 2008; Fernando et al. 2011, 2012). There are several data available concerning

Holzforschung, Vol. 63, pp. 529–535, 2009 • Copyright by Walter de Gruyter • Berlin • New York. DOI 10.1515/HF.2009.096 Article in press - uncorrected proof TEMPO-mediated oxidation of softwood thermomechanical pulp Yusuke Okita, Tsuguyuki Saito and Akira Isogai* Department of Biomaterial Sciences, University of Tokyo, Tokyo, Japan *Corresponding author. Department of Biomaterial Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan E-mail: Abstract A softwood thermomechanical pulp (TMP) was suspen- ded in

Introduction Thermomechanical pulps (TMP), a subcategory of mechanical pulps, are prepared from wood chips and used for newsprint paper. Mechanical pulps have the advantage of higher yields than chemical pulps, but the downside is that their production consumes a lot of energy. Among the most important parameters in refining conditions are temperature, moisture content (MC), refiner plate gap, and residence time. These have a substantial effect on fiber flexibility and bonding as well as the optical properties of the TMP (Illikainen 2008; Gorski et al. 2010

.Q., 2014. A Comparative Study on Thermomechanical Pulp Pressate Treatment using Thermophilic and Mesophilic Sequencing Batch Reactors. Environ. Technol. 35(11), 1409–1417. 23. Zheng M.R. Liao B.Q. 2014 A Comparative Study on Thermomechanical Pulp Pressate Treatment using Thermophilic and Mesophilic Sequencing Batch Reactors Environ. Technol 35 11 1409 1417 24. Zhu, I.X., Allen, D.G., Liss, S.N., 2009. Effect of Oxygen Partial Pressure and Chemical Oxygen Demand Loading on Biofilm Properties in Membrane-aerated Bioreactors. Water Environ. Res. 81, 289–297. 24. Zhu I

Preparation and some properties of the colloidal pitch fraction from a thermomechanical pulp Agne Swerin and Lars Odberg, STFI, Swedish Pulp and Paper Research Institute, Stockholm, Sweden Lars W ~ g b e r g , SCA Research AB, Sundsvall, Sweden Keywords: Pitch, Thermomechanical pulps, Colloids, Elec- trophoresis, Particle size distribution, Cationic compounds, Synthetic polymers. SUMMARY: A method is given for the preparation of a col- loidal pitch fraction from a TMP pulp. The following proper- ties of this pitch fraction have been investigated: size

525Nordic Pulp and Paper Research Journal Vol 19 no. 4/2004 KEYWORDS: Brightness reversion, Chelating agents, Dithionites, Iron, Peroxides, Polyphenols, Tannins, Thermomechanical pulps SUMMARY: Tannins are polymeric, phenolic constituents found in the bark of pine and spruce. When reacting with iron ions, tannins form strongly coloured complexes. Thus, the presence of bark in the mechanical pulping process leads to decreased brightness of the pulp. In order to evaluate the effects of the presence of iron on the properties of pulp, we have impregnated

229Nordic Pulp and Paper Research Journal Vol 19 no. 2/2004 KEYWORDS: Acid treatment, Brightness, Chelating agents, Colour reversion, Iron, Polyphenols, Sulphites, Tannins, Thermomechanical pulps SUMMARY: Tannins are polyphenolic compounds found mainly in bark. When reacting with iron, they form strongly coloured complexes, which through contamination from the bark may induce a brightness decrease of mechanical pulps. Wood itself contains phenolic compounds, which can form coloured complexes with iron. We have investigated gallotannin as a model for metal

PAPER PHYSICS Nordic Pulp & Paper Research Journal Vol 29 no (2) 2014 309 Paper strength improvement by inclusion of nano-ligno- cellulose to Chemi-thermomechanical pulp Sinke H. Osong, Sven Norgren and Per Engstrand KEYWORDS: CTMP, Fractionation, Nano-ligno- cellulose, Handsheet, Mechanical strength properties SUMMARY: So far, chemical pulp fibres have been utilized as conventional stock materials for nanocellulose production. The main aim of this work is to use stock materials from mechanical or chemi-thermomechanical pulping process to produce

. 201–225. Agarwal , U.P., McSweeny, J.D. ( 1997 ) Photoyellowing of thermomechanical pulps: looking beyond α-carbonyl and ethylenic groups as the initiative structures. J. Wood Chem. Technol. 17 : 1 –26. Agarwal , U.P., Ralph, S.A. ( 1997 ) FT-Raman spectroscopy of wood: identifying contributions of lignin and carbohydrate polymers in the spectrum of black spruce ( Picea mariana ). Appl. Spectrosc. 51 : 1648 –1655. Agarwal , U.P., Atalla, R.H., Forsskåhl, I. ( 1995 ) Sequential treatment of mechanical and chemimechanical pulps with light and heat: a Raman

214 E. Roffael et al.: TMP and CTMP for MDF Introduction Since the invention of the thermomechanical pulp process (Defibrator process, TMP-process) by Asplund in the thir- ties of this century it is known that defibration energy decreases with increasing temperature. Figure 1 shows energy consumption for defibrating wood as a function of temperature. Especially at temperatures higher than 150°C (hardwood) and 160 °C (softwood) a steep decrease in the energy input takes place. The basic principle is that the mid- dle lamella which has the highest lignin