Continuous anodizing and coloring process

Abstract

A process and apparatus for conducting an electrically independent current through an anodized web to electro-deposit a coloring agent on the web. A preferred process includes the step of providing a continuous web of anodized aluminum; transferring with a charging plate a coloring current to the web with a charging plate in a first treatment cell over an area of the web sufficient to allow the current to pass through an anodic layer of the aluminum and flow through the web; and electro-depositing coloring agents on the web with the coloring current in a second treatment cell. Optionally, the web may be serially passed through additional treatment cells to apply a variety of different coloring currents to the web whereby the web may be colored with multiple coloring agents and consequently exhibit multiple colors and/or refractive properties.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:  
     
         1 . A process for continuously anodizing and coloring a web of aluminum comprising the steps of: 
 applying an anodizing current to the web; and    applying an electrolytic current to the web wherein the electrolytic current is non-coincident with the anodizing current.    
     
     
         2 . The process of  claim 1  wherein a first coloring agent is deposited on the web during said electrolytic current applying step.  
     
     
         3 . The process of  claim 2  further comprising the step of repeating said electrolytic current applying step to deposit at least one second coloring agent on the web.  
     
     
         4 . The process of  claim 3  further comprising the step of controlling the application of the electrolytic current to the web to selectively control the deposition of at least one from the first and second coloring agents on the web.  
     
     
         5 . The process of  claim 2  further comprising the step of controlling the application of the electrolytic current to the web to selectively control the deposition of the first coloring agent on the web.  
     
     
         6 . The process of  claim 5  wherein the step of controlling the application of the electrolytic current includes adjusting one chosen from the amplitude, frequency, duration of application, and bias of the electrolytic current.  
     
     
         7 . A process for continuously coloring anodized aluminum comprising the steps of: 
 providing a continuous web of aluminum having an anodic layer;    applying a coloring current to the web over an area of the web sufficient to allow the coloring current to pass through the anodic layer and conduct through the web; and    electro-depositing a coloring agent on the web.    
     
     
         8 . The process of  claim 7  further comprising the step of repeating said electro-depositing step.  
     
     
         9 . The process of  claim 7  wherein the coloring agent is capable of being secured to the continuous web in a plurality of configurations, each configuration causing the web to refract light in a particular manner.  
     
     
         10 . The process of  claim 8  further comprising the step of controlling the refractive orientation of the coloring agent electro-deposited on the web.  
     
     
         11 . The process of  claim 8  further comprising the step of subjecting the web to at least one chosen from cleaners, detergents, etching solutions, and desmutting solutions.  
     
     
         12 . A process for anodizing and electro-depositing materials on a continuous web of aluminum comprising the steps of: 
 applying direct current to the continuous web in a first tank to anodize the web;    passing the web by a charging member in a second tank;    applying alternating current that is non-overlapping with the direct current to the anodized web with the charging member; and    electro-depositing a material on the anodized web in a third tank with the alternating current.    
     
     
         13 . The process of  claim 12  further comprising the step of controlling the alternating current to manipulate the configuration of the material deposited on the anodized web.  
     
     
         14 . The process of  claim 12  wherein the material is electro-deposited on the anodized web so that the web refracts light in a first manner.  
     
     
         15 . The process of  claim 14  further comprising the step of repeating said electro-depositing step.  
     
     
         16 . The process of  claim 15  wherein the material in the repeated electro-depositing step is deposited so that the anodized web refracts light in a second manner.  
     
     
         17 . The process of coloring a web comprising the steps of: 
 providing a continuous web of aluminum including at least one anodic layer;    applying a coloring current to the web through the anodic layer at a first station;    advancing the web to a second station including coloring agents; and    electro-depositing the coloring agents on the web with the coloring current.    
     
     
         18 . The process of  claim 17  further comprising the step of repeating said providing, said coloring current applying, said advancing, and said electro-depositing steps.  
     
     
         19 . The process of  claim 18  wherein the coloring current is applied through the anodic layer with a charging plate that imparts a voltage to a surface of the web.  
     
     
         20 . The process of  claim 19  wherein the charging plate imparts a positive voltage that penetrates the anodic layer.  
     
     
         21 . The process of  claim 20  wherein the charge is transferred from the plate to the web with the assistance of an electrolyte at the first station.  
     
     
         22 . The process of  claim 21  wherein the electrolyte is at least one acid chosen from sulfuric, phosphoric, nitric, and acetic acids.  
     
     
         23 . The process of  claim 22  wherein the second station includes a solution that enhances the application of the coloring current to the web.  
     
     
         24 . The process of  claim 23  wherein the solution includes salt chosen from tin, cobalt, silver, nickel, manganese, magnesium, selenium, zirconium and copper salts.  
     
     
         25 . The process of  claim 17  further comprising the step of controlling the refractive orientation of the coloring agents electro-deposited on the web.  
     
     
         26 . An apparatus for anodizing and coloring a web comprising: 
 means for producing an anodic layer on the continuous web by application of an anodizing current; and    means for electro-depositing a coloring agent on at least one from the web and the anodic layer by application of an electrolytic current wherein said electrolytic current is non-coincident with said anodizing current.    
     
     
         27 . The apparatus of  claim 26  further comprising a second means for electro-depositing a second coloring agent on the continuous web by application of said electrolytic current.  
     
     
         28 . The apparatus of  claim 26  further comprising a second means for electro-depositing a second coloring agent on the continuous web by application of a second electrolytic current wherein said second electrolytic current is non-coincident with said anodizing current and said first electrolytic current.  
     
     
         29 . The apparatus of  claim 23  further comprising at least one additional means for electro-depositing a material on the continuous web by application of at least one additional electrolytic current, said additional electrolytic current non-coincident with said anodizing current.  
     
     
         30 . The apparatus of  claim 23  wherein said electro-depositing process includes a member that transfers an electrical charge to the web through the anodic layer.  
     
     
         31 . An apparatus for coloring a continuous web of aluminum having an anodic layer comprising: 
 means for applying a first voltage current to the web through the anodic layer;    means for providing a first coloring agent; and    means for applying a second coloring voltage to the web whereby said first coloring agent is affixed to the web.    
     
     
         32 . The apparatus of  claim 31  wherein said first means includes a charging plate and imparts a positive voltage to a surface of the web.  
     
     
         33 . The apparatus of  claim 32  wherein the voltage penetrates the anodic layer and is conducted through an inner portion of the web.  
     
     
         34 . The apparatus of  claim 31  further comprising means for providing a second coloring agent.  
     
     
         35 . The apparatus of  claim 34  further comprising means for applying a third current to the web whereby said second coloring agent is affixed to the web.  
     
     
         36 . The apparatus of  claim 35  wherein said first and second coloring agents are affixed by electro-deposition on the web.