Characterization and utilisation of vine prunings as a wood substitute for particleboard production

The vine has been a traditional cultivation in Greece for many years. Every February after pruning, large quantities of vine prunings remain as byproducts in the field, non-utilized properly. The average amount of prunings per year reaches approximate to 5 t/ha, which is higher than the average yield of forests in temperate zones. The aim of the present work was to investigate the suitability of vine prunings, as a raw material for particleboards. After pruning, prunings from several varieties were chipped with an automobile chipper and re-chipped in a hammermill. Vine pruning particles and industrial wood particles in various proportions were used as the raw material for one-layer and for the core and surface layer of three-layer particleboards. In addition, material from vine prunings stored for 6 months in outdoor conditions was tested for its quality for particleboard production. A commercial urea-formaldehyde (UF)-resin was used as binder. Vine pruning particles were characterized by higher bulk density and lower slenderness ratio than industrial wood particles. The evaluation of the mechanical and hygroscopic properties of experimental panels showed the following results: partial substitution of wood by vine prunings negatively affects all board properties. However, the mechanical properties of three-layer boards, even those containing up to 100% vine pruning particles in the core, exceed the minimum requirements of the relevant European Standards (EN 312, Part 3, 1996) set for interior boards in dry conditions. The same happened with the hygroscopic properties. With the exception of the screw holding strength and formaldehyde release, the properties of boards made of vine prunings did not change substantially in comparison to those made of vine prunings stored for 6 months in outdoor conditions. (C) 2002 Elsevier Science B.V. All rights reserved.