(1): the extrusion coefficient of aluminum profile is too large, the extrusion temperature is too high (bar, tube, die three temperature), the extrusion speed is too fast.

(2): the extrusion pressure is unstable, suddenly high and suddenly low, or the speed difference between multi-speed regulation is obvious, the speed conversion is fast when changing gears.

(3): aluminum alloy profile extrusion head end pressure (stamping) too fast, tail end running speed or not decelerated, a lot of infiltration of the dead zone of aluminum.

(4) the quality of the rod is poor, the rod is over-burned, with large grains and loose. Residual pressure (V3 aluminum) is too thin.

(5): extrusion die velocity ratio serious imbalance unreasonable design and manufacturing.