The fast development of the wood-based panels industry during the last decades resulted in a substantially increased production capacity of manufacturing lines. The utilization of advanced manufacturing systems created a large output of different panel types with a production of more than 1,000 m3 per day on at least 300 days within a year. Therefore, it is important to take into account the new requirements for an on-line control of the manufacturing process. Only on-line Non-Destructive Testing (NDT) technologies are able to survey, detect, and forecast the quality of the raw materials, level of production parameters, and development of the panel properties. Main parameters like moisture content, resination level, mat area weight, thickness, and density profile influence the final properties of the panels. For over a decade there has been no other choice to control these and other process parameters than NDT methods using microwave (water content), IR (moisture and color), X-ray (mat and board area weight and density profile), ultrasound (blisters or density variation), etc. The determination of the effective resin content on the wood particle or the density, temperature, and moisture development during the hot pressing are further requirements for the future production units. The on-line measurement of free formaldehyde remaining after resin curing and other volatile substances from wood and resin seems to be a further subject of major interest. The intelligent implementation and integration, use, and understanding of on-line NDT methods in wood panel manufacturing is a big challenge that includes a better understanding of the overall process and its limits, an updated state of the art of knowledge, as well as an open and continuous dialog between the equipment producers, board manufactures, and users that could be another important key for the development of an environmentally friendly modern wood-based panel industry in the world.
Oversizing Thread Diagnosis in Tapping Operation
