INDUSTRI NYHEDER

What is the reason for the surface of the aluminum profile at normal temperature blackening? How to deal with it?

2019-05-05
The reason:
1 fedt, rust og skala fjernes ikke;
2 Efter fortyndingen vaskes den resterende væske ikke;
3 dele ryster for hurtigt;
4 parts overlap or fail to flip.

Approach: 
1 strengthen pre-treatment, degreasing and pickling;
2 Efter fortyndingen skal den resterende væske vaskes;
3 dele rystehastighed bør være passende;
4 parts should be flipped to prevent overlap.