Decorative and non decorative surfaces of aluminum profiles

     For an aluminum extrusion profile item, not all surface treatment films play an equally important role. The performance and appearance of the surface treatment film on some aluminium construction profiles has  a significant impact on the usage scenario, while the performance and appearance of the surface treatment film on some parts have little impact on usage.

     If they are not strictly controlled without distinguishing between primary and secondary, it is unreasonable from an economic perspective, therefore, the concepts of "decorative surface" and "non decorative surface"  are proposed and treated differently in industrial production and product standards (such as GB/T 5237.2-5237.5).  To control the thickness of the aluminium profile surface treatment film, it is necessary to ensure that the thickness of the film can be accurately measured. 

     When measuring film thickness, representative parts must be selected. In order to ensure the measurement results are as accurate as possible and have uniqueness in the event of disputes, arbitration methods are specified in relevant standards.