An investigation on the permeability of different wood furnish materials
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Heiko Thoemen
Abstract
In wood-based composite mats, mass and heat transfer are substantially influenced by their gas permeability. Thus, reliable permeability data are needed if one wants to model and simulate those processes taking place prior, during, and after hot-pressing operations of the mat. In this study, wood particles of surface and core layer type were obtained from two particleboard manufacturers, using impact mills and knife ring flakers, respectively. The permeability measurements were performed on the initial materials, as well as on subsets of it obtained by laboratory sieving. Additionally, medium density fibreboard (MDF) fibres from three species, namely pine (Pinus sylvestris), spruce (Picea abies) and rubberwood (Hevea Brasiliensis) were investigated. Cross-sectional and within-plane permeability was measured for densities from 250 to 1000 kg m-3. The permeability of the core particle materials was determined on solidified samples. On the other hand, the surface particles and MDF fibres were investigated by means of a rapid testing method on loose furnish materials (without solidification). MDF mats exhibited lower permeability values than particle mats at low densities, but values were found in the same order of magnitude for high densities. Mainly, the small particles determine the pore structure and permeability of particle mats. Thickness and in-plane size of particles affect the mat permeability, with the in-plane size becoming primarily effective at elevated densities. The permeability of MDF fibre mats depends more on the anatomy of the raw material than on its size distribution. We suggest, based on computer simulations, that only the within-plane permeability has a strong effect on gas pressure and temperature conditions during hot pressing. The cross-sectional permeability does not play an essential role in this regard.
©2008 by Walter de Gruyter Berlin New York
Articles in the same Issue
- Meetings
- Cellulose aerogels: Highly porous, ultra-lightweight materials
- Esterification of carboxylic acids on cellulosic material: Solid state reactions
- Bagasse alkaline sulfite-anthraquinone (AS/AQ) pulping and totally chlorine free (TCF) bleaching
- Effect of abnormal fibres on the mechanical properties of paper made from Norway spruce, Picea abies (L.) Karst.
- Development of fully bio-based composite: Wood/cellulose diacetate/poly(lactic acid) composite
- Crystallinity and mesoporosity of carbon produced from ligno-p-cresol and their improvement by pulverization and acid treatment
- Revisiting the mechanism of β-O-4 bond cleavage during acidolysis of lignin. Part 1: Kinetics of the formation of enol ether from non-phenolic C6-C2 type model compounds
- Study of kinetics of reaction of lignin model compounds with propylene oxide
- Two-dimensional homo- and hetero-correlation technique applied to NIR and py-MBMS spectra of wood
- UV resonance Raman spectroscopic study of photodegradation of hardwood and softwood lignins by UV laser
- A multivariate approach to the acetylated poplar wood samples by near infrared spectroscopy
- Structure elucidation of phenylethanoid glycosides from Paulownia tomentosa Steud. var. tomentosa wood
- A generalized mat consolidation model for wood composites
- Prediction and optimization of surface roughness in milling of medium density fiberboard (MDF) based on Taguchi orthogonal array experiments
- An investigation on the permeability of different wood furnish materials
- Laccase-catalyzed functionalization with 4-hydroxy-3-methoxybenzylurea significantly improves internal bond of particle boards
- Effect of thermo-mechanical refining pressure on the properties of wood fibers as measured by nanoindentation and atomic force microscopy
- Adhesive bond strength of end grain joints in softwood with varying density
- An experimental study of the effects of moisture variations and gradients in the joint area in steel-timber dowel joints
- A new image analysis algorithm for calculating percentage wood failure
- Dr. Gordon Leary
Articles in the same Issue
- Meetings
- Cellulose aerogels: Highly porous, ultra-lightweight materials
- Esterification of carboxylic acids on cellulosic material: Solid state reactions
- Bagasse alkaline sulfite-anthraquinone (AS/AQ) pulping and totally chlorine free (TCF) bleaching
- Effect of abnormal fibres on the mechanical properties of paper made from Norway spruce, Picea abies (L.) Karst.
- Development of fully bio-based composite: Wood/cellulose diacetate/poly(lactic acid) composite
- Crystallinity and mesoporosity of carbon produced from ligno-p-cresol and their improvement by pulverization and acid treatment
- Revisiting the mechanism of β-O-4 bond cleavage during acidolysis of lignin. Part 1: Kinetics of the formation of enol ether from non-phenolic C6-C2 type model compounds
- Study of kinetics of reaction of lignin model compounds with propylene oxide
- Two-dimensional homo- and hetero-correlation technique applied to NIR and py-MBMS spectra of wood
- UV resonance Raman spectroscopic study of photodegradation of hardwood and softwood lignins by UV laser
- A multivariate approach to the acetylated poplar wood samples by near infrared spectroscopy
- Structure elucidation of phenylethanoid glycosides from Paulownia tomentosa Steud. var. tomentosa wood
- A generalized mat consolidation model for wood composites
- Prediction and optimization of surface roughness in milling of medium density fiberboard (MDF) based on Taguchi orthogonal array experiments
- An investigation on the permeability of different wood furnish materials
- Laccase-catalyzed functionalization with 4-hydroxy-3-methoxybenzylurea significantly improves internal bond of particle boards
- Effect of thermo-mechanical refining pressure on the properties of wood fibers as measured by nanoindentation and atomic force microscopy
- Adhesive bond strength of end grain joints in softwood with varying density
- An experimental study of the effects of moisture variations and gradients in the joint area in steel-timber dowel joints
- A new image analysis algorithm for calculating percentage wood failure
- Dr. Gordon Leary
