Water Resistance of Wood-Based Panels Made without Binders
Journal Title: Lesnoy Zhurnal (Russian Forestry Journal) - Year 2020, Vol 8, Issue 3
Abstract
Water resistance of medium density panels made of hydrodynamically treated sawdust without binders was studied. It is customary to use panel swelling through-thickness after soaking in water for 24 hours and residual strength under static bending as criteria for water resistance. The effect of the following operation conditions of hot pressing on water resistance of panels was studied: temperature of press boards, specific pressing time and molding compound humidity. It is found that an increase in the temperature of press boards and specific pressing time results in a decrease in panel swelling through-thickness. The smallest value of this parameter was recorded at the press pulp humidity of 210 %. In comparison, the effect of boiling in water within 1 hour on the properties of the panels made of mechanically activated, as well as particle boards, high density fiberboards (HDF) and medium density fiberboards (MDF) of dry process was studied. It was found that the particle boards and medium density fiberboards were completely broken. High density fiberboards retained their shape, but the static bending strength was 89.7 % of the initial one. The panels made of mechanically activated wood particles had the static bending strength loss of 18.2 % of the initial one (before boiling – 22.4 MPa, after boiling – 17.4 MPa). The cyclic tests conducted according to the state standard GOST R 56309–2014 and by the “soaking–freezing–drying” method allowed us to find that the moisture deformations of the panels made of mechanically activated wood particles are reversible. As a result of 3 test cycles, a decrease in the static bending strength of the boards was 29.2 %. At the same time, their dimensions had no considerable changes. The value of residual swelling through-thickness was 0.62 %. The obtained results show that the preliminary hydrodynamic treatment of wood wastes (sawdust) allows making eco-friendly boards that have permanent water resistance. They can become widely used, especially under severe temperature and moisture conditions of operation.
Authors and Affiliations
V. N. Ermolin, M. A. Bayandin, S. N. Kazitsin, A. V. Namyatov, V. A. Ostryakova
Keywords
Related Articles
- EP ID EP683379
- DOI 10.37482/0536-1036-2020-3-151-158
- Views 243
- Downloads 0
Diversity of Common Hazelnuts (Corylus avellana L.) and Occurrence Forecast of Its Forms in the North-Western Caucasus
One of the most significant issues in common hazelnut biology and selection is the diversity (polymorphism) assessment of its fruits and the occurrence prediction of its forms with economically valuable features in natur...
Dendrochronological Studies of Wood at Historically Significant Sites of the Arctic
Studies of wood in the Arctic were carried out on Vaygach Island, Hooker Island (Franz Joseph Land) and Novaya Zemlya. During the expedition “Arctic Floating University – 2013”, wood samples (cores) were taken from the b...
Stem Volume Tables by Height Classes of Willow Trees in the Northern Taiga Region of the European Part of the Russian Federation
In order to improve the accuracy of forest inventory works, tables of stem volume by height classes of willow trees in the northern taiga region of the European part of the Russian Federation were created. Forest invento...
Minimizing the Chlorine Content in Bleached Sulfate Pulp for Sanitary Tissue products and Food Packaging
The increasing consumption of pulp for chemical processing, including production of sanitary tissue products and other medical products, food packaging, as well as fillers for food products leads to new requirements for...
Kinetics of Water-Alkaline Hydrolysis of Birch Bark in a Microwave Field
Birch bark consists of silver bark and bast. Silver bark contains up to 50 % of extractives and serves as a raw material for obtaining valuable biologically active substances (BAS), including betulin. A distinctive featu...