Factors affecting the size of aluminum profile（Five）

The amount of tensile straightening

After the extrusion die hole, in order to correct the twisting, bending and waves, the aluminum profile with high plasticity at high temperature is corrected in time, and it is often necessary to set a guide close to the mold outlet. The size and shape of the guide should be determined according to the size and shape of the product section, which is generally similar to the shape of the product. Some without a guide can use graphite strips to force the profiles to a certain direction and angle near the outlet, so the profile is initially straightened in the hot state.

Tensile straightening causes the aluminum profile to produce slight plastic deformation under the action of tension and achieve straightening.

When extruding from the hot state to the cold state, according to the principle of thermal expansion and contraction, the size of the product section will also become slightly smaller. Therefore, in order to ensure that the size of the extruded product is within the allowable tolerance range after stretching, the extruded profile must have a reasonable allowable tolerance (called extrusion deviation) before stretching.

In addition, it will also cause changes in the geometry of the section when stretching, such as the opening or closing of the opening part of the profile. In order to overcome these problems, c Pay attention to controlling the tensile elongation, choose the appropriate clamping direction, and use the method of adding straightening pads to solve the problem.