In-Mould Paint Thickness Control
In-Mould Paint Thickness Control
(OP)
I am working on improving application of in-mould paint with a PU system. Current method is using manual spray gun, but it is inconsistent and operator-dependent.
The method I had in moind was to use multiple nozzles to spray around the mould and (hopefully) obtain consistent even coverage.
1. Any suggestions of a nozzle that would do that? I imagine it would have to spray an ellipse pattern per nozzle, so a group of nozzles would provide for the required shape.
2. Any better ideas? Robots are out due to cost...
3. Related to the same issue, I have much difficulty measuring the thickness of the paint on PU. I attempted an ultrasonic gauge, but the readings were inconsistent on the same spot. To complicate matters, I believe the paint reacts to the PU so there is no real distinct boundary. Any suggestions?
Thanks!
The method I had in moind was to use multiple nozzles to spray around the mould and (hopefully) obtain consistent even coverage.
1. Any suggestions of a nozzle that would do that? I imagine it would have to spray an ellipse pattern per nozzle, so a group of nozzles would provide for the required shape.
2. Any better ideas? Robots are out due to cost...
3. Related to the same issue, I have much difficulty measuring the thickness of the paint on PU. I attempted an ultrasonic gauge, but the readings were inconsistent on the same spot. To complicate matters, I believe the paint reacts to the PU so there is no real distinct boundary. Any suggestions?
Thanks!





RE: In-Mould Paint Thickness Control
If you use metal molds, an accurate way to measure the DFT of the paint is by eddy current device. Most are handheld devices with a small probe on the end of a cable, so easy to measure on any ~flat surface (3/8" is fine, some can do on 1/4" flats). In aluminum anodizing, routinely measure to about 0.01 mil (0.25 micron). If your molds are steel, you can also use magnetic type instruments.
Some suppliers are Fischer & UPA.
http://www.fischer-technology.com/
http://www.upa.com/home.html
For measuring wet paint thickness (& other things), see
http://www.gardco.com/
What is PU? If you mean polyurethane, then only the wet film testers mentioned will work.
RE: In-Mould Paint Thickness Control
you're right - by pu i meant polyurethane.