A customer had a unique part that ink would not adhere to. They had tried using a flame treatment and chemical primer wipe. Both damaged the part by causing corrosion of the material and discoloration. The customer approached us about seeing if we had any ideas of what could work.
Our Steps Toward A Solution:
We received parts from the customer and tried variations of flame and chemical primers that our customer did not have access to. Similar issues happened as the customer had previously experienced. We then used a corona unit with the hope of the electrical charge having no adverse effects on the material. We achieved a dyne level that was adequate for printing, however marks that appeared as scratches were present on the part. While faint and less impactful than flame and chemical, it did not provide a solution that was acceptable to us or our customer. We experimented with using a mask of different materials to cover the area that was not to be printed, hoping to contain the scratch marks to the area that would be covered with ink. This still did not give us the proper result on the part we were looking for and we opened our options to techniques we were not as familiar with.
We reached out to a partner of ours with specialization in this area and they showed us another technique of using an electrical charge to pre-treat the material. This charge is similar to the corona we have used previously, but focuses it on a specific area of the part. This is done by using a unique metal within the fixture to act as a ‘lightning rod’ of sorts. This also allows a lighter voltage to be used while offering us an even higher dyne level due to the focus of the force. The end result was non-marked parts with high dyne levels. We then integrated that solution into our printer, giving our customer a simple solution to a complex problem.