COMPREHENSIVE METHODS FOR IMPROVEMENT OF PHYSICAL AND MECHANICAL PROPERTIES OF PARTICLE BOARDS

Abstract

Introduction. People use wood and wood composite materials in various fields since the ancient times . Growing consumption of wood and often irrational use of wood provoked much tension around the issue of low-grade wood and wood waste processing. Production of wood-based panels makes it possible to obtain a competitive structural material with a number of desirable properties and to complex use the wood and to recycle the wood waste. Production and consumption of woodbased panels in the coming years will inevitably increase, thus improving the physical and mechanical properties of particle boards will be given a special attention. The objective of the research is to make an analysis of the main ways to improve the physical and mechanical properties of particle boards. Current tasks: definition of the efficient and comprehensive ways to improve the properties of wood-based panels. Known complex ways for improvement of physical and mechanical properties of the particle boards. Physical and mechanical properties of wood-based panels depend on many factors. They are geometry of shavings, wood species, orientation of wood particles, usage of special additives, nature of the bonding of wood particles in the process of pressing and regulation of technological modes, use of new hardeners and fillers, methods of preparation and processing of chips, application of modified and new alternative binders. From the view point of the dimensional parameters of filler particles, the strength of the plates is maximum increasing when using long, thin and soft shavings. The phenomenon is explained by the increase of the area of contact of wood particles with each other and the number of adhesive layers. From the point of view of the quality of the bonded layer formation, it is fractionation occurrence of wood particles at the stage of the bonded layer formation which improves the strength characteristics. The properties of plates largely depend on the modes of hot pressing, thus increase in temperature and time compression contribute to increase of the strength of the boards. It is possible to improve the properties of the boards by means of the increase of the intensity of heating of the chip mat (method of "steam flow"). To improve the adhesion strength of bonding particles of filler, and, consequently, to improve physical and mechanical properties of boards, it is possible to use the new hardeners and fillers for binding and to process the fillers with the chemically active compounds. It is very effective to improve the properties of woodbased panels by modifying the binder used in production, and use of new alternative binders with the improved adhesive properties capable of forming durable and water-resistant adhesive bonding. Conclusion. Physical and mechanical properties of boards is possible to be improved through the use of modified or new alternative binder with better reactivity.