TRIESKOVÉ A BEZTRIESKOVÉ OBRÁBANIE DREVA 2010 9. – 11. 9. 2010 219 POPCORN-MODIFIED PARTICLEBOARDS Part 1 Mechanical properties Joanna Czechowska – Marcin Zbieć – Piotr Borysiuk Abstract Three-layer particleboards of reduced density (500 kg/m 3 ) were prepared. Core layers were blended with 30%wt or 50%wt of popcorn. Non-popcorn blended particleboards were used as the controls. Physical and mechanical properties of the boards were examined. 30%-popcorn containing boards exhibited reduced mechanical properties, however, their swelling was decreased when compared to the controls. Internal bond of the 50%- popcorn containing boards was also reduced, but their modulus of rupture, modulus of elasticity and 2- and 24-hr water swelling were comparable to the control series. Key words: popcorn, particleboard, mechanical and physical proprties INTRODUCTION Constantly increasing demand for wood generated by various sectors of industry (e.g. wood industry, power engineering industry) and increasing prices for raw wood make search for alternative resources more intense [Hikiert i Oniśko 2006, Marianowska 2006, Hikiert 2004]. Potential raw materials are annual plants (straw, cane stems, nut husk), waste wood and other materials (tanned leather, waste paper, thermoplastics) [Gürü at al. 2006, Grigoriou 2003, Pawlicki 2001, Piotrowski 1999, Tröger at al.1998, Youngquist 1995, , Mohamad Jani at al. , Sedliaćik M., Pivoluska J. 1990]. Using of these resources allows for savings in raw wood consumption. On the other hand, development of low-density wood based composites seems to be promising way to reduce wood consumption and meet the requirements of furniture market and consumers expectations [Thoemen 2008]. The objectives of this work were investigations on using popcorn as an alternative material and examining the properties of the resultant popcorn-modified particleboards. It is worth noting that low-density boards are the boards of density 620 kg/m 3 or lower which is the density limit for the industrial particleboards in Poland.