Heat and mass transfer in wood composite panels during hot pressing: Part 3. Predicted variations and interactions of the pressing variables
-
Changming Yu
Abstract
As a continuation of previous publications on a physical-mathematical model of heat and mass transfer and a structural model of mat permeability, this paper presents typical prediction results for 15 pressing variables for strand mats. A case study and complete solutions to the governing equations are provided. The results show how the heat and mass transfer is controlled by heat conduction and convection involving gas flow and phase change. The model predictions provide a comprehensive illustration of the temporal and spatial variations of basic pressing variables, including mat temperature, gas pressure, moisture control and resin curing rate. The model offers a powerful tool for simulating the effects of mat structure, pressing schedule and initial mat conditions.
References
Bolton, A.J., Humphrey, P.E., Kavvouras, P.K. (1989) The hot pressing of dry-formed wood-based composites: Part III. predicted vapour pressure and temperature variation with time, and compared with experimental data for laboratory board. Holzforschung43:265–274.Search in Google Scholar
Carvalho, L.M.H., Costa, C.A.V. (1998) Modeling and simulation of the hot-pressing process in the production of medium density fibreboard (MDF). Chem. Eng. Commun.170:1–21.Search in Google Scholar
Dai, C. (2001) Viscoelastic behaviour of wood composite mats during consolidation. Wood Fibre Sci.33:353–363.Search in Google Scholar
Dai, C., Steiner, P.R. (1993) Compression behaviour of randomly formed wood flake mats. Wood Fibre Sci.25:349–358.Search in Google Scholar
Dai, C., Yu, C. (2004) Heat and mass transfer in wood composite panels during hot pressing: Part I. A physical-mathematical model. Wood Fiber Sci.36:585–597.Search in Google Scholar
Dai, C., Yu, C., Hubert, P. (2000) Modelling vertical density in wood composites during hot-pressing. In: Proceedings of the 5th Pacific Rim Bio-based Composites Symposium, 10–13 December 2002, Canberra, Australia.Search in Google Scholar
Dai, C., Yu, C., Zhou, X. (2005) Heat and mass transfer in wood composite panels during hot pressing: Part II. Modeling void formation and mat permeability. Wood Fiber Sci.37:242–257.Search in Google Scholar
Humphrey, P.E., Bolton, A.J. (1989) The hot pressing of dry-formed wood-based composites. Part II. A simulation model for heat and moisture transfer and typical results. Holzforschung43:199–206.Search in Google Scholar
Thoemen, H., Humphrey, P.E. (2003) Modeling continuous pressing for wood-based composites. Wood Fiber Sci.35:456–468.Search in Google Scholar
Zombori, G.B., Kamke, F.A., Watson, L.T. (2003) Simulation of the internal conditions during the hot-pressing process. Wood Fiber Sci.35:2–23.Search in Google Scholar
©2007 by Walter de Gruyter Berlin New York
Articles in the same Issue
- MWL fraction with a high concentration of lignin-carbohydrate linkages: Isolation and 2D NMR spectroscopic analysis
- Papermaking properties of the ECF-bleached kraft pulps from first-thinning Scots pine (Pinus sylvestris L.)
- Syntheses and properties of liquefied products of ozone treated wood/epoxy resins having high wood contents
- Quality control of thermally modified timber: Interrelationship between heat treatment intensities and CIE L*a*b* color data on homogenized wood samples
- Violet light causes photodegradation of wood beyond the zone affected by ultraviolet radiation
- Dynamic mechanical analysis of dry wood: Linear viscoelastic response region and effects of minor moisture changes
- Material properties and their interrelation in chemically modified clear wood of Scots pine
- Effect of treatments with 1,3-dimethylol-4,5-dihydroxy-ethyleneurea (DMDHEU) on the tensile properties of wood
- Penetration of amino-silicone micro- and macro-emulsions into Scots pine sapwood and the effect on water-related properties
- Search for a relationship between stress wave velocity and internal stresses in eucalypts and radiata pine
- Kiln-drying lumber quality of hybrid poplar clones
- Heat and mass transfer in wood composite panels during hot pressing: Part 3. Predicted variations and interactions of the pressing variables
- Heat and mass transfer in wood composite panels during hot pressing: Part 4. Experimental investigation and model validation
- Dielectric relaxation of water adsorbed on wood and charcoal
- Properties of piezoelectric voltage considering the microscopic structure of wood cell walls
- Adjusting for fibre length-biased sampling probability using increment cores from standing trees
- External and internal fungal flora of pine sapwood (Pinus sylvestris L.) specimens in above-ground field tests at six different sites in south-west Germany
- Award Presentation on the occasion of the European Workshop on Lignocellulosics and Pulp (EWLP 2006) in Vienna
- Phenolic compounds in silver birch (Betula pendula Roth) wood
Articles in the same Issue
- MWL fraction with a high concentration of lignin-carbohydrate linkages: Isolation and 2D NMR spectroscopic analysis
- Papermaking properties of the ECF-bleached kraft pulps from first-thinning Scots pine (Pinus sylvestris L.)
- Syntheses and properties of liquefied products of ozone treated wood/epoxy resins having high wood contents
- Quality control of thermally modified timber: Interrelationship between heat treatment intensities and CIE L*a*b* color data on homogenized wood samples
- Violet light causes photodegradation of wood beyond the zone affected by ultraviolet radiation
- Dynamic mechanical analysis of dry wood: Linear viscoelastic response region and effects of minor moisture changes
- Material properties and their interrelation in chemically modified clear wood of Scots pine
- Effect of treatments with 1,3-dimethylol-4,5-dihydroxy-ethyleneurea (DMDHEU) on the tensile properties of wood
- Penetration of amino-silicone micro- and macro-emulsions into Scots pine sapwood and the effect on water-related properties
- Search for a relationship between stress wave velocity and internal stresses in eucalypts and radiata pine
- Kiln-drying lumber quality of hybrid poplar clones
- Heat and mass transfer in wood composite panels during hot pressing: Part 3. Predicted variations and interactions of the pressing variables
- Heat and mass transfer in wood composite panels during hot pressing: Part 4. Experimental investigation and model validation
- Dielectric relaxation of water adsorbed on wood and charcoal
- Properties of piezoelectric voltage considering the microscopic structure of wood cell walls
- Adjusting for fibre length-biased sampling probability using increment cores from standing trees
- External and internal fungal flora of pine sapwood (Pinus sylvestris L.) specimens in above-ground field tests at six different sites in south-west Germany
- Award Presentation on the occasion of the European Workshop on Lignocellulosics and Pulp (EWLP 2006) in Vienna
- Phenolic compounds in silver birch (Betula pendula Roth) wood
