Valmet IQ Web Gloss Measurement
The accurate scan averages and high-resolution CD profiles measured by Valmet IQ Web Gloss Measurement (IQ Web Gloss) provide a solid foundation for Valmet’s cross-direction gloss profile controls.
IQ Web Gloss is used for control of paper surface quality on online and offline calenders. Digital signal processing and dust compensation ensure maximum measurement accuracy. IQ Web Gloss is factory pre-calibrated to TAPPI gloss measurement standards.
IQ Web Gloss measures the reflectivity of a paper and board sheet using paper industry standard optical geometry defined by TAPPI. A light beam at an angle of 75 degrees from the vertical is reflected to a greater or lesser extent by the surface of the sheet. As the sheet’s gloss increases the reflected light intensity measured by the sensor’s detector increases.
The sensor head measuring window surface contains air curtain and measurement chamber is over pressurized to minimize dust accumulation.
A sheet stabilization device that uses “coanda effect” technique, ensures excellent measurement accuracy even with sheet flutter. This single-sided, non-contacting sensor can be mounted on either side of the sheet for two-sided quality control.
- More accurate and stable onsheet measurements for precise control of MD and CD sheet surface quality.
- Minimum waste on online and offline calenders.
- Precise streak control using high resolution profiles, available after the very first sheet scan.
- Faster on-spec quality and reduced startup waste.