Preparation of Wood Filler for Arbolite

Abstract

The effect of treating the wood filler of freshly cut wood species with the additive of silica sol obtained by the polycondensation method on the arbolite properties is studied. It was found by X-ray fluorescence spectroscopy that silica sol particles with the sizes of 20 to 80 nm are adsorbed on the surface of the wood filler, obstructing open pores and spaces between the wood vasculars. The most effective is the additive of silica sol with its content from 10 to 20%. It is shown by the a multilayer map of energy-dispersive X-ray spectroscopy of a wood particle treated with silica sol that calcium cations accumulate on the wood filler in the arbolite mix, thus affecting the hydration of the cementing material and the arbolite strength. After 3 and 28 days of hardening, the strength of the arbolite with the birch chips increases by 2.5-2.7 and 2.7-3.1 times, respectively; with the aspen chips its strength becomes 3.1-4.2 times higher; and the arbolite strength rises 3.1-4.2 times with birch and pine chips (1:1). The method for treating the wood filler with silica sol patented by the authors makes it possible to simplify the technology of its preparation, to reduce the exposure time of wood filler before mixing with a cementing material and to produce arbolite from freshly cut birch wood with the strength after 3 and 28 days of hardening being 2.5-2.7 and 2.7-3.1 times higher than that of the control composition.