Ceramic flame powder coating result in Black colour

[iwan-sedaryawan]

Dear all,
Does anyone has any experience to spray ceramic flame powder coating by using Metco 5PII gun spray the results / powder coated to material is in Black Colour ??, we have used Titanium oxide powder but the colour is grey one, since my customer is a textile factory very fanatic with black colour result of sprayed ceramic powder, cause the original is black-coloured.
Thanks in advance.

[Gordon]

Hi iwan-sedaryawan

Titanium dioxide (titania) and various alumina/titania (13-50%) can produce black or blue/black coloured coatings (Metco 102, 110, 130, 131VF). Amazing considering titania powder is white and is often used as a white pigment in paints etc.

The colour can be effected by your gun set-up and spraying procedure. Increasing numbers of poorly heated particles in the coating will make coating lighter and more grey/blue. Preheating substrate to 100-120*C and not allowing lower temperatures during spraying are important. Experiment with your speeds and feeds. To get and maintain good black colour can be a bit of an art Also sealing will improve appearance. Are you using the cross air jet accelerator unit on the 5P-II?

[iwan-sedaryawan]

Hi iwan-sedaryawan

Titanium dioxide (titania) and various alumina/titania (13-50%) can produce black or blue/black coloured coatings (Metco 102, 110, 130, 131VF). Amazing considering titania powder is white and is often used as a white pigment in paints etc.

The colour can be effected by your gun set-up and spraying procedure. Increasing numbers of poorly heated particles in the coating will make coating lighter and more grey/blue. Preheating substrate to 100-120*C and not allowing lower temperatures during spraying are important. Experiment with your speeds and feeds. To get and maintain good black colour can be a bit of an art Also sealing will improve appearance. Are you using the cross air jet accelerator unit on the 5P-II?

Hi Gordon,
Appreciated to your quick reply, will check to our operator for the air jet accelerator, how about chrome oxide effected to the colour ? can be achieve black coloured than Titania/Alumina ?

[Gordon]

Hi iwan-sedaryawan

Chromium oxide coatings tend to be more of a dark grey than black (depends on your definition of a black coating ). Note also that deposit efficiency through the 5P-II are very low (<20%). Chromium oxide/silica (136F) or chromium oxide/titania (111) may be better.

Best to experiment with spray technique and a few different powders and see which ones your customer prefers.

[iwan-sedaryawan]

Hi Gordon,
Okay, will do as per your suggestion above and hv a nice Monday......

[erick212]

I agree that the spray parameter is very important to the color. I have never used a flame spray gun to burn ceramic only plasma guns. I produced a very black coating with Norton/St Gobain #108. I was also able to get a mostly black(some greyish) with a Chrome oxide powder from Stark. I cannot remember the powder ID off the top of my head but can find it if you like.-

[Gordon]

Appearance may also differ depending on post spraying treatments. Colour of as-sprayed coating may look quite different when sealed or finished ground/polished. I use to like looking at rolls/shafts with ground/polished coatings of this type, where the appearance was more like wood, showing light and dark "wood" grain patterns. Not a desired effect but pretty This is where various layers of differing qualities are exposed on the surface.