WOOD RESEARCH Volume 69, Number 4, 2024
TOMÁŠ MELICHAR, SILVESTR VASAS, JIŘÍ BYDŽOVSKÝ, ŠÁRKA KEPRDOVÁ, AMOS DUFKA, and IVETA NOVAKOVA

INFLUENCE OF PARTICULATE MIXTURE CONTAINING STABILISED WOOD ON LONG-TERM BEHAVIOUR OF WOOD-CEMENT COMPOSITES. CASE STUDY

This paper presents research on the changes in the properties of cement-bonded particleboard modified with particulate mixture (PM). PM replaced 4% of the binder (cement) and 4% of the filler (spruce chips). The cement-bonded particleboards were tested for physical (bulk density, swelling, linear expansion due to relative humidity changes) and mechanical properties (modulus of rupture and modulus of elasticity). Development of phase composition and microstructure by XRD and SEM were also analysed. The long-term behaviour of wood-cement composites was studied over a period of 2 years. The physical, mechanical properties and microstructure of the modified particleboards were compared with commercially produced cement-bonded particleboards from CIDEM Hranice, Inc. There is no intentional change in properties when using PM compared to the reference boards and the values reached the EN 634-2: 2007

WOOD RESEARCH Volume 64, Number 1, 2019
Chuangui Wang, Rongrong Li, Chengqian Liu, and Xiaodong (Alice) Wang

Effects of medium-low temperature hydrothermal treatment on microstructure and dimensional stability of chinese sweetgum wood

To investigate the changes of microstructure and dimensional stability during hydrothermal treatment, the Chinese sweetgum (Liquidambar formosana Hance) wood samples were treated in a numerical show constant temperature water bath with temperature of 60, 80 and 100°C for 4 h. The dry shrinkage rate and water absorption of untreated and treated samples were measured. Scanning electron microscopy (SEM) was selected to observe and investigate the changes of wood microstructure, which caused by hydrothermal treatment. The results showed that dry shrinkage rate increased from 4.92% to 7.00% and 9.62% to 10.12% in tangential direction and radial direction, respectively. However, the shrinkage rate difference (SRD) as an index to evaluate possibility of wood deformation, decreased from 1.96 to 1.45, which meant the shape stability of treated samples improved. The water absorption increased from 93.15% to 112.11%. From the results of SEM, the most sediment on aspirated pits were removed and pit membrane was ruptured after treatment. It had positive effect on moisture migration and wood permeability. It is maybe the reason of the variation of water absorption and dry shrinkage rate.