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Quality Assurance and Testing
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Quality Assurance and Testing

Through various process controls coil anodizers are able to monitor and control the correct anodized coating for your application.



Quality Criteria

Anodize film thickness                  
Anodize film uniformity
Anodize film density
Abrasion resistance
Corrosion resistance
Fade resistance
Reflectivity
Image clarity
Insulative properties
Adhesion
Sealing
Applicable Tests

G.M.C. Cass Test
Ford fact test
Salt spray
Weatherometer
Fadometer
U.V. Con
Acid dissolution (ASTM B136-63T)
Weight test
Microscopic test
Dielectric test
Light section microscope
Colorimeter
Dorigon



















Fabrication Guidelines and Techniques

Pre-anodized aluminum coil can be used in nearly all fabricating operations with exceptions of deep drawing and extruding.

Stamping and Blanking

No major modifications in tool design are necessary.
Reduce male-female die clearance to 2%-8%
Keep dies sharp
A looping pit ahead of the press allows for smooth coil feeding
Synthetic grippers on feed work best.
Lubricants may be eliminated, depending on the process.
Use lintless gloves when handling pre-anodized stock.
Anodized blanks are protected and stackable.

Rollforming

Often, no change in tooling is necessary when converting
from another metal.
Pre-anodized aluminum will take all minimum bend radii
as specified by the Aluminum Association.
Just as with stainless steel, keep tooling polished
Chrome-plated rolls often perform best.
Using polyfilm will sometimes eliminate the need for lubricants. 
   
Laminating

Polyfilm protection is helpful.
Leave it on through the process.
Clean the substrate with a clean brush.
Cut the sheet to size with shears or saw. Be sure they are sharp.
Experiment with saw and feed speed on scrap.
Cut into the sheet so that rough edges are on the back of the sheet.
Spray-grade contact adhesives work best. Apply them on the aluminum first, then on the substrate.
Bending (Break Press)

Handle pre-anodized stock similar to other metals
Various dies can be used.
Half hard tempers are most often used because of their formability and structural integrity
Where possible, use a scrap of anodized sheet to adjust the depth of stroke required to accomplish the desired bend.
Gradual bending will help to minimize crazing.
Strippable polyvinyl films will help protect the surface during the bending process.

Other forming operations that are successful with pre-anodized aluminum are perforating, shallow drawing, seam welding, and roller leveling. It can also be easily slit and sheared.

Reprinted with permission of Continuous Coil Anodizers Association.