Reflection of oil mark on aluminum profile surface:
The oil stain of aluminum profile does not wipe up before aging. After aging, it produces watermark on the surface of aluminum. After oxidation, it appears dark spot and has certain depth.
Cause of oil mark on aluminum profile surface:
1. Cut oil stains on both ends of the aluminum profile with the finished saws. The gloves are not clean or even covered with graphite dust when moving (lifting) materials.
2. When the aluminum profile was stretched, the dirty material of the gloves was too long and the saw was not removed.
3. Leave "marks" on the dirty gloves during processing;
4. Oil leakage of extrusion equipment and tools (driving, hoisting belt).
Method for eliminating oil mark on aluminum profile surface:
1. During the process of aluminum production, the gloves should be clean and the oil stains should be removed timely when lifting and lifting the aluminum profile.
2. Take proper materials when stretching aluminum;
3. Sorting, lifting gloves and stretching materials, separate gloves when adding sticks;
4. Pay attention to oil leakage of equipment and tools.
Characteristics of aluminum profile surface watermark:
The surface of aluminum profile appears silver-gray wet - like imprint spot, aluminum profile with the intensity of oxidation alkaline wash and reduce or disappear.
Causes of aluminum profile surface watermarking:
The aluminum profile surface is partially wet by water, and infiltrates into the aluminum matrix through the small holes in the quenching and oxidation layer of the profile surface, forming trihydroxyl alumina, which becomes bright and light with the duration of water retention. If there are impurities (salt, nitrite, etc.) in the water, corrosion spots will occur.
Elimination of aluminum profile surface watermark:
The aluminum profile with water should be dried immediately, and it must be dried before aging. If the condition permits, the alkali washing time and oxide film thickness should be increased appropriately.
To sum up, oil stains and water stains will not result in oil marks and watermarks as long as the aluminum profile is not stained with dust before aging. The key is to cultivate good operating habits and quality awareness.There has been a low quality accident using oily paper as profile liner with oil stains after self-efficacy.
