I am currently working on a project that requires a section of "release liner" to be removed and a clear plastic to be put in its place after a few holes are punched out of the paper. What I am trying to figure out is how to detect if the plastic did indeed cover all of the glue or if there is glue present. An addition to this would be to check and make sure that the release liner is also removed in the current section.
It would be preferred to do this without contact since there is very little room to test if there is glue present (on the surface) before it goes into the next stage of the process.
The materials used are as follows: light-brown chipboard (type of cardboard/heavy paper) that is backed with glue on 1 side White (semi-glossy) release liner that sits on top of the glue Clear (PET) thin plastic backing which is very reflective
Thoughts that I have had, but do not know what avenues to pursue are bouncing a laser off of the surface and measuring the amount reflected back and also ambient reflection to detect if it is bouncing off of a white surface.... Any and all avenues, tips, and/or help will be greatly appreciated.