Coating Metrology
Measurement of the thickness of a liquid coating immediately after application determines the eventual dry film properties and coverage. Determining the wet film thickness is a necessary in-process control for ensuring that adhesive or barrier coatings are applied uniformly. Specialized gauges like notched combs or wheel-type instruments are used to measure this dimension on the moving web.
This measurement allows real-time adjustments to the coating station before the material enters the drying oven. Monitoring this initial state helps technicians adjust process parameters dynamically to maintain target specifications.
Application Uniformity
Maintaining the correct liquid thickness prevents defects such as puddling and incomplete coverage. The relationship between wet and dry thicknesses is calculated using the solid-volume percentage of the coating formulation. If the applied wet layer is too thick, it may run or fail to cure completely, leaving a tacky surface.
Consistent monitoring ensures that raw material consumption remains within the target budget.
Dry Film Optimization
Uniform wet application is essential for achieving the required dry barrier properties against water, oxygen, or grease. Thin spots in the wet film lead to pinholes and barrier failures in the finished packaging material. Continuous feedback loops from automated gauges adjust the metering roll speed or blade pressure to maintain the set thickness.
