Abstract
Sludge of pulp and paper mills have natural adhesive properties. The primary sludge (PS, contains fibers) and secondary sludge (SS, contains proteins) could also be suitable for manufacturing medium-density fiberboard (MDF). Protein in SS can react with formaldehyde (HCHO), and as an additive in urea-formaldehyde (UF) resins it can reduce formaldehyde emission. Thus, SS was investigated in the present study. PS and SS were collected from two mills and characterized in terms of chemical composition, fiber length distribution, pH, and buffering capacity. MDF samples were processed according to an experimental design, in which UF resin content was reduced from 12% to 8% and replaced by SS in the range of 5%–15%. Gel time measurement showed high SS reactivity with UF resin. The SS reduced HCHO emissions by up to 68% compared to control panels, without compromising internal bond strength. The bonding effect of SS was lower than expected due to the high pH, thus the buffering capacity reduced UF performance. Moreover, sludge reduced bending performance. Dimensional stability was the greatest disadvantage of sludge panels.
©2011 by Walter de Gruyter Berlin New York
Articles in the same Issue
- Publisher’s Note
- Publisher’s Note
- ORIGINAL ARTICLES
- Brightness reversion of eucalyptus kraft pulp: Effect of carbonyl groups generated by hypochlorous acid oxidation
- MgSO4 vs. Mg(OH)2 as a cellulose protector in oxygen delignification
- Hydrogen peroxide and supercritical carbon dioxide: a new bleaching stage for Eucalyptus kraft-O2 pulps
- Preparation and physical characterization of strongly swellable oligo(oxyethylene) lignin hydrogels
- Activation of pine kraft lignin by Fenton-type oxidation for cross-linking with oligo(oxyethylene) diglycidyl ether
- Determination of pectin content of eucalyptus wood
- Theory of transport processes in wood below the fiber saturation point. Physical background on the microscale and its macroscopic description
- The effect of galactan content on the mechano-sorptive strain in loblolly pine
- Genetic and environmental variation in heartwood colour of Australian blackwood (Acacia melanoxylon R.Br.)
- Aging of wood: Analysis of color changes during natural aging and heat treatment
- Thermal behaviour of Norway spruce and European beech in and between the principal anatomical directions
- Air-coupled ultrasound inspection of glued laminated timber
- Optical characteristics of wood investigated by time-of-flight near infrared spectroscopy
- Comparison of NDE techniques for assessing mechanical properties of unjointed and finger-jointed lumber
- Potential of pulp and paper sludge as a formaldehyde scavenger agent in MDF resins
- FT-IR imaging microscopy to localise and characterise simultaneous and selective white-rot decay within spruce wood cells
- Effects of ionic strength, monoethanolamine, copper, and pH on adsorption of alkyl dimethyl benzyl ammonium chloride in wood
- Long-term performance of fused borate rods for limiting internal decay in Douglas-fir utility poles
- SHORT NOTE
- Composition of the heartwood essential oil of incense cedar (Calocedrus decurrens Torr.)
- Meetings
- Meetings
Articles in the same Issue
- Publisher’s Note
- Publisher’s Note
- ORIGINAL ARTICLES
- Brightness reversion of eucalyptus kraft pulp: Effect of carbonyl groups generated by hypochlorous acid oxidation
- MgSO4 vs. Mg(OH)2 as a cellulose protector in oxygen delignification
- Hydrogen peroxide and supercritical carbon dioxide: a new bleaching stage for Eucalyptus kraft-O2 pulps
- Preparation and physical characterization of strongly swellable oligo(oxyethylene) lignin hydrogels
- Activation of pine kraft lignin by Fenton-type oxidation for cross-linking with oligo(oxyethylene) diglycidyl ether
- Determination of pectin content of eucalyptus wood
- Theory of transport processes in wood below the fiber saturation point. Physical background on the microscale and its macroscopic description
- The effect of galactan content on the mechano-sorptive strain in loblolly pine
- Genetic and environmental variation in heartwood colour of Australian blackwood (Acacia melanoxylon R.Br.)
- Aging of wood: Analysis of color changes during natural aging and heat treatment
- Thermal behaviour of Norway spruce and European beech in and between the principal anatomical directions
- Air-coupled ultrasound inspection of glued laminated timber
- Optical characteristics of wood investigated by time-of-flight near infrared spectroscopy
- Comparison of NDE techniques for assessing mechanical properties of unjointed and finger-jointed lumber
- Potential of pulp and paper sludge as a formaldehyde scavenger agent in MDF resins
- FT-IR imaging microscopy to localise and characterise simultaneous and selective white-rot decay within spruce wood cells
- Effects of ionic strength, monoethanolamine, copper, and pH on adsorption of alkyl dimethyl benzyl ammonium chloride in wood
- Long-term performance of fused borate rods for limiting internal decay in Douglas-fir utility poles
- SHORT NOTE
- Composition of the heartwood essential oil of incense cedar (Calocedrus decurrens Torr.)
- Meetings
- Meetings