A customer came to me last week with a troublesome problem to him and not so unusual application for us. He had an application where a magnetic strip is hot stamped onto small plastic cards (similar to credit cards). After the stamping process a vision system inspects the back of the card for defects in the stamping and / or the rest of the back surface. The problem with the application is that small dust particles get onto the plastic part prior to stamping which can cause holes in the magnetic tape stamping part and also show up as defects in the quality of the part elsewhere across the back side. The result is a rejected part due to contamination.
The customer already had an “air bar” of some sort blowing onto the parts but that was not getting rid of the debris which was determined to have a static charge and thus attracted debris. Once it was determined the air bar was not effective, the customer went on the hunt for something more appropriate to cleaning the sub-strait of the product. They found EXAIR rather quickly and contacted me with the above problem.
After discussing the points of the application, I recommended a couple of 6” Super Ion Air Knives to run on a single, two-outlet power supply to blow the parts free from the dust contamination. The parts travel on a rotary table to be processed through loading, initial blow-off, stamping, secondary blow-off and then inspection. A photo of the Super Ion Air Knife in position over the table follows:
The result: The customer was able to significantly reduce the number of rejects due to contamination from the static charged debris. Only true defects are being found by the vision inspection system which has improved the application’s effectiveness for turning out good quality product.