-- The Home Page of the Finishing Industry

on this site
current topics
Live! From beautiful Pine Beach New Jersey: Welcome to the world's most popular metal finishing website

topic 3824

Aluminum Color Dye & Pigments


Dear Sirs,

We are now intending to develop a series of products that are made of aluminum, in various colors. We had cooperated with our material supplier and anodizing factory to work together and the basic sulfuric anodizing process for clear anodizing seems can be solved.

The problem is, we find it is difficult to maintain the stability of colors during dyeing production and the usual colors we know are limited. We know that this is a usual problem for a beginner in this industry according to many factors that may influenced. But, surely , we have confidence to solve the factors step by step with the aid of factory and from your expertise.

We want to know is there any pigments or methods that can take anodizing and coloring at the same process ? We are looking for numbers of colors.

Do anyone knows any quality suppliers that can supply the above said pigments/ chemicals ? Or, is there any stable and quality organic/ inorganic chemicals suppliers that can assist in this to maintain a slighter variations during dyeing mass production.

All comments are highly appreciate and with deep thanks !

Sammy Shum
- Hong Kong


I don't know if there is any pigment that can be used during anodizing. But about the stability of the colour, I've talked to a pigment supplier before, and they said there is virtually no way of controlling the stability(in a factory setting at least), all is down to the experience of the factory. The pigment company's advice for me is to go for a reputable anodizing company. And all the pigments currently used are organic, so degradation is inevitable. About colours, if you order is big enough, e.g. >5 kg, you can ask the pigment company to customize colours for you. Or, you can mix your own colour with existing colours, but then again, that depends on experience, cause a lot of factors, e.g. particle size or pH of the pigment, can affect the results. My advice for you, go and ask the pigment supplier(good one of course), they probably know more than the anodizing factory, this is particularly true in the PRC region.

Doris Wong
- Hong Kong

First of two simultaneous responses--


Exact color match from one lot to another is extremely difficult. Close is possible with great care. The first is the aluminum. It is never exactly alike, even from the same lot number. It gets worse with extrusions and is nearly terrible with castings. Things like the rate that it cooled down makes a difference in how it anodizes.

No production facility controls its solutions exactly. They use a range. The amount of aluminum and other metals dissolved in them makes a difference in the surface. thus the color appearance.

It is not easy to maintain an exact dye concentration, which affects the color.

The largest affect, after surface condition, is the anodizing process. A 1 degree C difference makes a difference in the pore size which affects the color adsorption. The next is the amount of anodize, thickness, which also affects the amount of dye absorbed, which affects the color appearance.

All reputable dye manufacturers have a stability rating for each dye. It makes a difference.

Some dyes have a metal constituent also and are not purely organic.

It takes a serious amount of control of every parameter to get very very close color match.

Normally, it is a tradeoff of cost vs the acceptable color match.

James Watts
- Navarre, Florida

Second of two simultaneous responses--


Sammy, The best way to control your dyes is to purchase from a reputable dye manufacturer. They are listed in the Metal Finishing Guide Book Directory.

For proper control of all colors we used to do a daily analysis for pH, temperature and twice per week a colormetric check. The dyes are all expensive.

Proper anodize bath controls are necessary as well as very good clean water rinses after anodize. The seal following dyeing cannot be overlooked.

Bill Hemp
tech svc. w/ chemical supplier - Grand Rapids, Michigan

If you have a question in mind which seems off topic, please Search the Site

ADD a Q, A, or Comment on THIS topic START an UNRELATED topicView CURRENT HOT TOPICS

Disclaimer: It's not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices

©1995-2019, Inc., Pine Beach, NJ   -   About   -  Privacy Policy
How Google uses data when you visit this site.