Apple Inc.
Protecting anodized surfaces during manufacturing processes

Abstract:

Treatments for anodic coatings that provide improved resistance to staining and cracking during various manufacturing processes are described. According to some embodiments, the methods include placing the anodic coatings in partially sealed states by sealing only the outermost portions of the anodic coatings, which protect the outer surfaces of the anodic coatings from contamination and staining. Inner portions of the anodic coatings are left unsealed, thereby making the anodic coatings more compliant and resistant to cracking when exposed to manufacturing processes, even those that involve exposure to high temperatures or high mechanical stress. Subsequent to the processing, another sealing process can be implemented to fully seal the anodic coatings so that they provide good corrosion and wear resistance.