The air bend is to form a bending moment through the one -way contact with the outer roller and the outer wall of the tube billet. The air curve will compress the curved wire. This is the compression/thickening effect of air bending.
1) The advantage of the air bending is that the side length can be bent when the real bend is not bent. The air bend can also bend the inner corner of the R <0.2t without a broken wall.
2) The disadvantage of air bending is that when the square tube is synchronized with air bending on the top/side, due to the pressure of the upper roller and the lower roller, the molding force is easy to surpass the critical point, resulting in the inner concave of the sideline The unit is running stably and the quality of molding. This is also a different characteristic of the square tube and the round tube air bending.
