aluminum oxide porous structure quantifying

[Manifolddesigner]

Hello,
I work for a consumer electronics company and we're currently looking at improving our quality control wrt our anodized aluminum products. Most are clear ano, some colored.
I've got a handful of samples in front of me that measure very very close in surface roughness (1.8->4.0 micro meters Sa), color photo-spectrometer, and gloss.

The problem we've got is our ID guys say that " this one looks great, but this one looks like rubbish and we could never sell a product this horrible!". I can barely tell a difference, but I'm not an Industrial Design guy.

what other ways are there to quantify a surface?

I found a white paper for a university doing semi-conductor research on ano alum all about the pore size and pore structure. Would a difference in pore size or shape or pore regularity, the organizational structure show up visibly?

We've got a strictly outlined internal anodizing procedure, but no real way for an inspector to say if it is in 'spec' or not beyond the aforementioned measurements which don't seem to be up to the task.

Jason

 

[CoryPad]

Another parameter to study is DOI, or Distinctness of Image. This incorporates small variations in surface geometry that lead to perceived quality of the surface. Here is one instrument that measures DOI:

http://www.byk.com/en/instruments/appearance/orange-peel-doi.html

 

[Manifolddesigner]

Have you used one of those or are you related to them in some way? I've been looking at that product already and talking to the sales rep who ... has been difficult. I'd hate to dismiss a useful tool because I don't get along with the rep.

JM

 

[unclesyd]

Take a look at the model 6000.

http://www.defelsko.com/applications/anodizing/Anodizing.htm

For many years we used a homemade IR light box to superficially scan anodized parts.

 

[CoryPad]

I have used a BYK DOI instrument in the past, and I am not affiliated with them at all. They are standard items for surface measurement in the automotive industry.