Economic efficiency, sustainability and the CO2 balance are dominant topics of discussion in production departments. At the same time, in many areas of the wood and furniture industry, it has so far been virtually impossible to adequately monitor a very decisive factor in this context - the amount of lacquer applied. For example, when coating flat substrates with roller coating, the amount of lacquer applied can only be checked at longer intervals. However, when roller coating flat substrates, changes in temperature and humidity very quickly lead to a significant increase or decrease in viscosity and therefore a change in the applied coating thickness. A uniform and consistent coating can only be guaranteed by continuous and precise monitoring of the coating thickness. In many applications, coating thicknesses that are too low quickly lead to complaints, while coating thicknesses that are too high waste resources and drive up costs - not to mention the CO2 footprint. Too thick a coating, however, leads to increased costs, a worsened CO2 balance and, under certain circumstances, to quality defects in appearance.
No alternative to manual weighing until recently
Manually coating and weighing samples introduced into the process is not only time-consuming, but also prone to errors, as well as having a significant impact on employee motivation and diligence. The methods already on the market for non-contact coating thickness measurement were too susceptible to interference from temperature and humidity fluctuations in the wood and furniture production environment. This problem gave a paint manufacturer no peace of mind and he came up with an interesting solution for measuring paint application quantities continuously and without contact.
New measuring method meets requirements and can determine the degree of curing of UV coatings
The development team came up with the idea of testing a process that is already in use in the wood processing sector - but for determining the moisture content of the wood. The measurement method used for this is based on near-infrared spectroscopy (NIR). They contacted a company that manufactures such NIR spectroscopy measurement systems for the previously known applications and it quickly became apparent that the approach was promising. As a result, the measurement methodology was adapted and a corresponding measurement system was developed and validated in an astonishingly short period of less than a year. However, the measuring system also offers another highly relevant capability for the industry. Using NIR spectroscopy, it is possible to determine the degree of curing of a UV coating based on the signature of the molecular groups created by the curing process.
Readmore in the upcoming print issue mo 7-8/2024 of mo and soon on oberflaeche.de!