The geometry of wood particles has a significant influence on the properties ofparticleboard. However, this relationship has been difficult to use for process optimization so far. The expansion of process control to include particle thickness measurement opens up new possibilities for using wood and adhesives more efficiently and thus conserving resources.
Depending on the technology applied, wood particle dimension measurement in the context of process control and optimization is less meaningful, incomplete or very time-consuming. The sieve analysis provides a combined characteristic of dimension and shape, which is referred to as particle size. The two-dimensional, image-analytical measurement of put down particles is limited to particle length and width, the measurement in free-falling particles (2D and 3D) is differently precise depending on the particle orientation to the camera. Although the three main geometric particle axes can be determined with manual caliper measurement, this method is labour-intensive, time-consuming and has limited reproducibility. Since the particle geometry has a significant influence on the panel properties and thus on the possibility of process optimization, the "3D-Span" project intends to develop an image analysis system for the automated, three-dimensional determination of wood particle dimensions and a technique for taking samples.
Wood-based panel industry
A laser profile scanner is to be used to measure the wood particles. It records a digital height profile of the particles separated on a conveyor belt. In contrast to the use of a line scan camera, the particle thickness, surface area and volume can be determined in addition to particle length and width. On the basis of this data, various characteristics are calculated with which particles can be characterized and compared. The functionality of the measuring device is to be tested and its suitability for process optimization is demonstrated by the experimental measurement of various particles. A reproducible sampling, which is also developed within the scope of the project, is important for a high selectivity of the measuring instrument.
The Thünen Institute is interested in finding out how reliably and precisely the measuring device developed determines the particle dimensions. This is particularly true with regard to sampling. The basic question is whether the new technology can be used to increase material and energy efficiency in particleboard production and thus conserve resources.
12.2017 - 5.2020
Project funding number: ZF4430102GR7
Funding program: Innovationsförderung
Project status: finished
Benthien JT, Heldner S, Lüdtke J (2019) Spandicke bildanalytisch messen : Thünen-Institut für Holzforschung und Grecon entwickeln System zur 3D-Vermessung von Spänen. Holz Zentralbl 145(38):800 PDF Dokument (nicht barrierefrei) 703 KB
Benthien JT, Heldner S, Lüdtke J (2019) Vorteile durch bildanalytisches Messen der Spandicken : Neue Technik zur Überwachung der Spangeometrie vereinfacht Steuerung und Optimierung des Spanplattenprozesses. Holz Zentralbl 145(50):1101-1103 PDF Dokument (nicht barrierefrei) 2859 KB
Benthien JT, Lüdtke J, Friehmelt R, Schäfer M (2018) Technical Note: Limitations of a 3-D image analysis-based particle size measuring system for wood particle dimension measurement [online]. Wood Fiber Sci 50(3):358-362, zu finden in: https://wfs.swst.org/index.php/wfs/article/view/2653 [zitiert am 05.11.2018]