Plastic products on coating thickness measurement problem

1. The transfer method was used to measure the points for attention during the coating on plastic playground products
A survey of coating on plastic products. Such as using the ultrasonic measurement, often occurs because of coating and substrate miscibility and no better acoustic reflector, which leads to failure or read value serious deviation measurement. If using this method, also has to use more inconvenient and reading difficulties. So now in general use portable electronics factory transfer method measuring coating on plastic products.
After many years of practice, we recommend the first article products cover a number of small the standard thickness of polyester film (about 100 microns, my company has specialized customized supply), then the paper crepe tape pressure at both ends, set aside the middle section. Put the product in normal spraying, baking spray line.
, remove it after the completion of the products with paint film of the polyester film, with a zero of iron plate zero (or aluminum plate) substrate with magnetic induction (or eddy current method) film thickness gauge measured part coated and uncoated part, the difference between the two is the coating thickness.
Due to use the same park bench of zero board, so the electromagnetic induction reference point will not change, so as to ensure the measurement benchmark unchanged, ensure accuracy of the measurement. In addition, particularly because of the difference method is used, so the instrument and the error of zero board will be offset by subtraction. Thus greatly reduce the claim to the zero plate and the precision of instrument. If use our company design and manufacture of precision PHYNIX stents and Germany company produces the thickness gauge, repeatability can be raised to 0.2 microns.
Also have some factories still adopt the method of pasting iron and aluminum, it's important to note that each variation of surface roughness of iron or aluminium, convex concave deformation, thickness change will cause electromagnetic induction change reference point, this may cause measurement error and repeatability is poorer. Need to pay attention to avoid it.
2. The coating thickness measurement of other problems
A. coating baking after curing, and a slow process, continue to curing due to the constraints, the factory will be measured after general to remove products. Often measured again like a day or two days later, the thickness will be less 1 ~ 3 microns.
B. as for thickness slice method, preparation section is very important. Due to the soft base material and coating, cutting deformation may cause the coating to the substrate or base material extrusion occupy in the direction of coating, resulting in the reading small or large.
Another paint coating process is liquid dot after sputtering to base material, the flow flat, crosslinking, curing film. Section must be a state of surface of ups and downs, the exterior point of view, presents the orange peel phenomenon. Transfer method of thickness is randomly take on plane, or averaged them again, sectioning is cut in a straight line section on microscopic visual reading. For both take different points method, location, the reading will be different. But both have reference value to each other, can be analyzed to find out reasons.