Application of coating thickness gauges in plastic products
Measurement of coatings on plastic products. For example, when using ultrasonic measurement, there is often no good sound wave reflection surface due to miscibility between the coating and the substrate, resulting in measurement failure or serious deviation of the reading value. If the wedge method is used for measurement, it is often inconvenient to use and difficult to read. Humidity sensor probe , , Stainless steel electric heating tube PT100 sensor , , Cast aluminum heater , Heating ring Fluid solenoid valve, so currently portable electronic product manufacturers generally use the transfer method to measure the coating on plastic products.
After many years of practice with coating thickness gauges, we have summarized a method, which is to first cover the product with several small strips of polyester film of standard thickness, and then use paper-based masking tape to press the two ends, leaving the middle part. Put the product into the spraying line for normal spraying and baking.
After the product is completed, remove the polyester film with the paint film left on it, use an iron zero plate (or aluminum zero plate) as the substrate, and use a magnetic induction (or eddy current method) film thickness meter to measure the coated part and the uncoated part respectively. part, the difference between the two is the coating thickness. Since the same zero board is used, the electromagnetic induction reference point will not change, thus ensuring that the measurement benchmark remains unchanged and the accuracy of the measurement is ensured. In addition, especially since the difference method is used, the errors of the instrument and the zero plate will be canceled out by subtraction. This greatly reduces the requirements for zero plate and instrument accuracy.
Some factories still use the method of pasting iron sheets and aluminum sheets. It should be noted that the different surface roughness, convex and concave deformation, and thickness changes of each iron sheet or aluminum sheet will cause changes in the electromagnetic induction reference point, which may cause measurement problems. Increased error and poor repeatability. Need to be careful to avoid.
