Laser mark Validation sample prep

Hi all,

I'm having a bit of an argument with the President of my company. We are developing validation protocols for a laser marking machine used to mark medical devices. My stance is that different worst case raw materials need to be considered as well as surface finishes, i.e., reflective, non-reflective, coated, etc. So there should be samples that are bead blasted, satin finished, LFC coated, TiN, PVD, etc. He is arguing against that and says we can just mark the parts straight from the CNC machine. He has a consultant he's worked with in the past that is telling him it's not necessary to consider different surface finishes.

My question is, am I going way overboard here? I understand his reticence as it would obviously increase time and cost.

Validation should always be done across the extremes of allowable variation. (Should = must to be a true a validation, otherwise you have what is called a biased sample that only validates the portion tested)

BUT it must be the allowable variation per specification. Why are you thinking abou using different material finishing techniques? Will you be using all of these? Or are you trying to create a range of surface finishes?

Laser marking is a whole case of cans of worms

If a part with the wrong surface finish is processed through the laser marker, will it still pass the data mark evaluation criteria (assuming for a moment that you are marking a 2D matrix). If it fails (and not 'just barely') then you have at least some assurance that your process is protected. I would suggest trialing 1 sample of each of the potential surface finishes, and then make further decisions.