The properties of fibreboard are as diverse as their use: insulating boards, for example, have a low density and are composed of coarse fibres, whereas medium and high density fibreboard (MDF/HDF) have a uniform surface and are made of much finer fibres.
In industrial production, most process variables and product characteristics are monitored by modern measurement technology. But, to date, control of pulp quality is just performed by tactical and optical inspection by experienced personnel. An objective, efficient measuring method is not available but of major importance, because the fibre quality is a key quality parameter for the panel.
The Thünen Institute for Wood Research, together with partners, has developed a new system for the optical measurement and size characterization of fibres from wood and other renewable raw materials: FibreCube.
FibreCube is a system which enables a reliable, robust and reproducible measurement of hundreds of thousands of fibres within a few minutes. The fibres are completely separated with an innovative approach prior to the analysis. Through a prudent combination of compressed air and ultrasound, the particles are separated and then subjected to a software-based image processing. Thus, the recent problems with the characterisation of fibres, the separation woolly matted fibre clumps and the measurement of overlapping captured fibres, are solved. After the image processing the objects are sucked from the glass plate, so that the next measurement can begin. About 0.5 g fibre material is measured per run, 650 images are created for evaluation and measured by the software. On average 200,000 fibres are characterised per run.
The data and key figures calculated from these measurements are summarised in a so-called "Fibre Fact Sheet". For example, the frequency distribution of the measured length of all fibres, the average fibre length and the coarse particle fraction in the sample are of particular interest.
The FibreCube provides the wood materials industry the opportunity to optimise processes in order to save energy costs and reduce emissions.