Effects of saturated vapor pre-steaming on drying strain in Asian White Birch: Experimentation and modelling

Abstract

The effect of low pressure saturated vapor pre-steaming on restrained shrinkage strain, mechanosorptive creep and the distribution of moisture content was investigated during conventional drying of wood discs. Mechano-sorptive creep was furthermore modelled by artificial neural network theory with five inputs, i.e., pre-steaming and drying temperatures, wood moisture content, relative humidity and distance from the pith. Results revealed that, pre-steaming partly reduced the variation of moisture content distribution along radial direction, increased restrained shrinkage strain in heartwood and decreased in sapwood and slightly decreased the mechano-sorptive creep. The neural network model provided reasonable prediction results, namely, the coefficient of determination for training, validation and test sets greater than 0,95.

The Effect of the Beech Wood Steaming Condensate on Curing Behaviour of Urea-formaldehyde Adhesive

“…This physico-chemical process characterized by elevated temperatures, a steam atmosphere, high wood moisture content, and the presence of microorganisms, initiates the chemical reactions in wood: degradation processes of primary wood components, cellulose, hemicellulose, and lignin followed by the extraction of water-soluble substances into the wastewater solution (Dzurenda et al 2022). While steaming is usually employed to equalize (or change) the colour of wood, it also offers bene ts such as growth stress reduction (Gril et al 2017), reduced initial moisture content and moisture content gradient (Fu et al 2019), improved drying characteristics (Milić et al 2015), increased dimensional stability (Fruhwald 2006) and reduced surface roughness (Dudiak et al 2024). For beech timber -one of the most important hardwood species in Europe -steaming is pivotal in enhancing the aesthetic appeal and market value of wood products.…”