Reasons for aluminium profile die marks(welding lines) and the solution

1, the die itself causes: the die structure is not reasonable, die clamping is itself a dislocation, die venting is not good

2, aluminum billets after die, metal by cutting directly below the midline of the rib site there is an obvious dividing line, aluminum on the so-called welding wire. But the rib below aluminum metal deformation degree is the largest, hydrostatic pressure is low, if get the extrusion die with work, after aluminum oxide, surface appear black line defect. Extrusion dies the reasons there are many kinds of welding wire, oil, too fast, good low temperature may cause, welding wire. If tap hole flow unevenly, the rib on both sides of hydrostatic pressure difference is big, weld line position offset chamfer position under the rib, causing welded serious adverse, under the rib instead of lead Angle on the aluminum flow severely hampered, on both sides of the metal because of large difference of deformation, lead to serious color aluminum.
Welding lines can be removed? Welding line is different from other parts of the organization structure, contact with the acid and alkaline bath can form different from other parts of the bright line or black line. Avoid contact with acid, alkali, chemical polishing is using a strong acid so can't remove. As far as possible to eliminate only change the mould diversion structure, make the mould clamping line moved to the decorative surface or corner position, also increase guide plate can have a try. Of course can also change the surface treatment, in conclusion as far as possible to avoid contact with acid,.alkali
.