The proper extrusion press is mainly determined by the extrusion ratio. If the extrusion ratio is too low, the mechanical properties of the aluminum profile are low; if the extrusion ratio is too high, aluminum surface products are prone to defects such as surface roughness and angular deviation.
The size, weight, and strength of the profile determine the overall dimensions of the extrusion die, that is, the outer diameter and thickness of the extrusion die.
The extrusion die hole size
If the aluminum profiles with large wall thickness differences, the die hole size should be appropriately enlarged.
Reasonable aluminum metal flow rate
Try to ensure that every particle on the section of the aluminum profile should flow out of the die hole at the same speed. When designing the extrusion die, try to use a porous symmetrical arrangement. According to the shape of the aluminum profile, the difference in wall thickness of each part, the difference from the perimeter, and the distance from the center of the extrusion barrel, the sizing belts of different lengths are designed.
The extrusion die strength
Due to the harsh working conditions of the mold when aluminum profiles are extruded, mold strength is a very important issue in die design. In addition to rationally arranging the positions of die holes, selecting appropriate die materials, and designing reasonable die structures and shapes, it is also important to accurately calculate the extrusion force and check the allowable strength of each dangerous section. As for the check of the mold strength, it should be carried out separately according to the type of product and mold structure.
Reasonable working belt size
Determining the working band of the split combination mold is much more complicated than determining the working band of the half mold. Not only the difference in profile wall thickness, the distance from the center but also the surface of the mold hole must be considered.
Structure and size of die hole blank knife
The die hole blank knife is a cantilever support structure at the exit end of the die hole working belt. When the thickness of the aluminum profile is ≥2mm, a straight knife structure that can be easily processed can be used; when t <2mm, an inclined hollow knife can be processed at a cantilever.