The Valmet IQ Coat Weight Measurement (IQ Coat Weight) is a single-sided, direct measurement of coating weight on paper or board. Ideal in scanner applications for calcium carbonate, latex and clay-based coatings, the sensor can be used with multi or single-station coaters.
Utilizing Valmet’s patented technology, the IQ Coat Weight is a robust measurement solution for film coating and folding boxboard coater applications. Fully digital signal processing and factory pre-calibration ensure the IQ Coat Weight sensor is accurate from day one.
A superior signal to noise ratio and excellent accuracy is achieved by using dedicated processors with DSP technology in each sensor head. Built-in calibration, diagnostics, and temperature stabilization techniques ensure accurate readings even in hot, dirty environments. The sensor readings are also unaffected by sheet flutter.
On a multi-station coater, coat weight is measured by a single sensor after each coating application. For better precision, an additional IQ Coat Weight sensor on the base sheet measures marker agent content from recycled broke.
Infrared energy is absorbed at specific wavelengths by sheet materials. Analyzing over a dozen wavelengths in the near and middle infrared ranges, the marker agent (clay, calcium carbonate or latex) is directly measured to determine the coating weight on one side of the sheet. Optionally, the sensor can simultaneously measure the surface moisture content and the temperature of the sheet.
Coating color on the other side of the sheet does not interfere with the sensor reading. This makes it possible to accurately and independently measure film coatings that are applied simultaneously on both sides using two single-sided sensors on the same IQ Scanner.