[imbaqai]

Hello everyone:

I have just started a job which deals heavily in heat sealing using polyurethane adhesives. I have some theoretical know how of organic chemistry and polymers and I am very interested in this. I am hoping to learn things through this forum. My question is if I want to determine transference of translucent or white (TiO2) adhesive on a white substrate, is there any stain test that I can use for quick confirmation? visual and small hand held microscope is not helpful. Any advice???

[ARGOS++]

Dear Imbaqai;

Usually Quality Control for Coatings for both cases: with or without Pigments is taken with so called “Reflection/ Reflectance -Spectrometers” for a wide field.
Several use a so called 3-Angel Method (20°, 60°, and 85°) for Gloss too.
There are several ISO, DIN, ASTM, BS, and other standards named for.
I don’t remember all Numbers and their correct “Quality-Parameter”.
As Examples you may search for ISO 2813, ISO 7668, ASTM D 523, BS 3900, and a Lot of other.
For sophisticated measurements you should not use "3-Filter-Colorimeters", you should use real Spectrometers with “Ulbricht-Spheres” and a “Gloss-Option” for the three angels, and a wavelength increment of about 10nm.

Most time you are then able to distinguish between the different whites from the ground and the TiO2 and estimate also the thickness of the coatings in case of partial translucence.
In lacquering manufacturing you are also able to make Quality Control for metallised finishing.
I don’t have to tell, that you are also able to make shade control, pigment mixtures, and others too, but you must use an adapted “Kubelka-Munk” equation, because it is not exactly the same as for fabrics.
But you have to keep in mind, that in most applications you have to do a so called Calibration.

I hope it gives you at least an idea.

Good Luck!
                    ARGOS⁺⁺

[imbaqai]

Dear Argos:

Thank you for your reply. I will follow the suggestions and research them. As I had indicated that I am new to this field so a lot of things that you have indicated are new to me, but I will do research and learn. I will certainly post more questions as I learn.

Bst rgds,