Q: I have a laser 2D mark and associated human readable marking on a shiny aluminum part. Do you know of any coating method that can be used to help preserve the marking and protect against dirt, grime, sand, etc? I’m more concerned with the 2D mark than the hri. The supplier 2D isn’t currently blackened like some of your website examples – it can be read though. – Craig M.
A: Thanks for your question, Craig. I think you are looking for a way to protect the mark you have created on the aluminum part to ensure that its scanability does not diminish appreciably over time, correct?
Scanning a laser marked symbol on a reflective surface is one of the more challenging applications in our industry. Not all scanners can successfully read a low contrast symbol and particularly a low contrast symbol that has been worn from use or environmental conditions.
One solution that comes to mind is to apply a thin protective “lens” over the mark to protect the integrity of the mark against sand, grime, chemicals, etc. Of course this protection method must be acceptable to the applications specifications and function, but could be a viable solution. We have created a product made specifically for protecting labels in harsh environments called SandShield that may be effective for your applications as well. This plastic material would be die cut to a size large enough to cover your mark and is held in place with pressure sensitive adhesive. This material was tested by the Naval Surface Warfare Center in Corona, CA. In the harshest test, SandShield protected the mark from stones and debris dropped from 50 feet on to the mark. The test was done until failure. Other products failed after on or two drops, however SandShield endured multiple drops.
We can provide a few samples of SandShield that we recommend you test by installing it over a sample mark to see that the scanner still reads the mark though the plastic SandShield and test its durability under your expected conditions. All I’d need is the sample size(s) you’d like and where you want us to send it.
We also think you could improve your results by increasing the contrast of the mark before you protect it. We have a special fade resistant dye called Polycolor Black that can be rubbed into the relief areas of the symbol and greatly increase contrast. Now, if you place the SandShield protective material over the enhanced mark you will have a superior solution that is high contrast and fully protected.
I’d be happy to assist you further or you can contact Randy Uveges at 800-627-3917.