Influence of Density on the Withdrawal Staple Strength from Hemp Shive Panels

Abstract

Particleboards are the main material used in the production of furniture and furnishings. The shortage of wood raw material and the everincreasing amount of particleboards produced suggest a search for alternative raw material sources for this panel type. On the other hand, significant quantities of agro-industrial lignocellulosic residues are available worldwide. Such a type of residue is hemp shives. Basic joints in furniture frames are stapled joints, as it should be said that density is the main characteristic of particleboards, and their other properties strongly correlate with it. The present research studies the influence of the density of panels from hemp shives on their staple withdrawal resistance. For this purpose, panels from hemp shives with melamine-formaldehyde (MF) resin as an adhesive and densities from 600 kg.m^-3 to 900 kg.m^-3 were produced in laboratory conditions. The density of the panels varied with a step of 100 kg.m-3. As a result of the research, it was found that the staple withdrawal resistance of hemp shives particleboards from the edge and side of the panels increases almost twice with the increase of their density. It was also found that, unlike industrial particleboards, edge staple withdrawal resistance is higher in hemp shive panels than side staple withdrawal resistance. Laboratory-produced panels from hemp shives have a higher staple withdrawal resistance at similar densities than industrial particleboards. However, this is at the expense of using expensive MF resin and the significantly extended press factor. The main novelty of the research is the establishment of the effect of the density of hemp shive particleboards on their staple withdrawal resistance, as well as the demonstration of the possibility of producing panels from an alternative lignocellulosic raw material with a better staple withdrawal resistance than that of industrial particleboards manufactured from wood raw material.