1. Stretching must be carried out after the
aluminum alloy profile is cooled to below 50 degrees, and can be moved to the stretching frame for stretching. If the temperature is too high, stretching will burn both the body and the wool tops. The internal stress of the
aluminum alloy profile cannot be completely eliminated,which lead to tortuous, twisted, and dysfunctional absolute waste before and after aging.
2. The amount of stretching is controled at 1%, and it should be noted that the excessive stretching will cause head-to-tail size error, the appearance of water-like , twist (fish scale) marks, low elongation, high hardness and brittleness (low plasticity). Too low tensile strength will make the compressive strength and hardness of the
aluminum profile low, and even the aging (quenching) can not improve the hardness. The aluminum profile is easy to Arc twists (commonly known as the big knife bend).
3. In order to control the amount of tensile deformation and very good control of the scale change of the whole profile, it is necessary to select a suitable special cushion and a suitable method. In particular, the opening material, the arc material, the cantilever material, and the zigzag shape’s profile should pay more attention to the reasonable and effective use of the stretching cushion.
4. Pay attention to the force condition of small feet, thin teeth, long legs, circular faces, inclined faces, ope , and viewpoints of profiles with high width-to-thickness, long cantilever, large curvature, and strange shape. The situation, to avoid deformation of the profile part or point scale, twisting, spiral and other shortcomings occur.
5. Because wool tops have the effect of resisting heat, the
aluminum profiles with high decorative appearance requirement must be turned upside down to keep uniform heat dissipation, reducing the disadvantages of lateral bright spots caused by uneven heat dissipation and crystallinity. Especially the wide width and, thick aluminum profiles should pay attention to it.
6. Do not rub, pull, stack, congest or entangle each other during the process of reclaiming, moving and stretching, and reserve a certain interval between each other. For
aluminum alloy profiles with easy tortuous and long discharge lengths, it needs timely dispose.
