INDUSTRIA BERRIAK

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

2019-05-05
Tarrazoi zuen:
1 koipea, herdoila eta eskala ez dira kentzen;
2 Beltzez gero, hondar likidoa ez da garbitu;
3 parts are shaking too fast;
4 piezak gainjartzen dira edo ez dute irauliko.

Approach: 
1 strengthen pre-treatment, degreasing and pickling;
2 After the blackening, the residual liquid should be washed;
3 parts shaking speed should be appropriate;
4 parts should be flipped to prevent overlap.