Introduction to the Application of Coating Thickness Gauge in Plastic Products
Measurement of coatings on plastic products. When using the ultrasonic method for measurement, it is common for the coating to dissolve with the substrate, resulting in a lack of a good acoustic reflection surface, leading to measurement failure or serious reading deviation. If the cutting wedge method is used for measurement, there are also many areas where it is inconvenient to use and difficult to read. Humidity sensor probe, stainless steel electric heating tube PT100 sensor, cast aluminum heater, heating coil fluid solenoid valve
Therefore, currently portable electronic product manufacturers generally use the transfer method to measure the coating on plastic products.
We have summarized a set of methods through years of practice on coating thickness testers, which involves first covering the product with several small strips of standard thickness polyester film, and then pressing both ends with paper based masking tape to leave the middle part. Place the product on the spraying line for normal spraying and baking.
After the product is completed, remove the polyester film with paint film and use iron (or aluminum) plate as the substrate. Use a magnetic induction (or eddy current method) film thickness gauge to measure the coated and uncoated parts, and the difference between the two is the coating thickness. Due to the use of the same zero plate, the electromagnetic induction reference point will not change, ensuring that the measurement reference remains unchanged and accurate. In addition, especially due to the use of the difference method, the errors of the instrument and the zero plate will be offset by subtraction. This greatly reduces the requirements for zero board and instrument accuracy.
Some factories still use the method of pasting iron and aluminum sheets. It should be noted that different surface roughness, convex and concave deformation, and thickness changes of each iron or aluminum sheet can cause changes in the electromagnetic induction reference point, which may increase measurement errors and poor repeatability. Care should be taken to avoid it.
