Classical methods of thickness measurement
To ensure quality and durability of different products, a final coating of polymers is applied increasingly. An even layer thickness, prevention of volatile harmful substances and meeting required mechanical characteristics cannot be assured without inspections during the manufacturing process. Often the surface of the product is structured and classical methods of thickness measurement (e.g. interferometric methods) fail.
The spectrometers uniSPEC2.2S and the uniSPEC2.2P combined with the probes PSP-D or PPA are versatile tools for the simultaneous determination of the coating composition and the coating thickness in a laboratory environment. The multiplexed NIR-spectrometer uniSPEC2.2MPL is suitable for process control. This process spectrometer can be equipped with a probe line PMAmpl or up to 64 single probes. The latter can be distributed at different spots of the production facility. The single probes are attached to the multiplexer by optic fibre cables. A continuous and consistent surveillance of product bands can be achieved by the hyperspectral imaging cameras uniSPEC1.9HSI and uniSPEC2.2HSI including the illumination unit PMAmsi.
Example: Determination of layer thickness of polymers on paper
Spectra of 1 to 5 micrometer thick acrylate layers on paper: A correlation between spectra curve and layer thickness is clearly seen in the figure. A routine for the determination of the layer thickness is included in the software KustaWIN.