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Ningbo Yinzhou Defa Aluminum Profile Accessories Co.,Ltd
Add:No.44 Lengshui'an Road, Yinjiang Twon, Haishu Zone, Ningbo, China
Aluminum Profiles Complexity, Diversification

In recent years, with the rapid development of China's large-scale infrastructure investment and industrialization process, the production and consumption of aluminum profile industry has grown rapidly, and China has also become the largest aluminum production base and consumer market in the world. After nearly 10 years of rapid growth, China's aluminum industry has entered a new stage of development, and has shown a lot of new development trends.

Moreover, with the rapid development of construction, transportation, automobile, solar energy and led industries, the high precision and high performance requirements of aluminum alloy extrusion products are increasing day by day, and the shape of profile section is complicated and diversified, which is designed according to common form and has many shortages. Therefore, to get high-quality profiles, we have to continue to learn and accumulate in the production, life, continuous transformation and innovation.

Die design is an important link, therefore, the extrusion profile mold design should be systematically analyzed, and through the production practice to solve the problem gradually.

The size and deviation of the extruded parts are determined by the tooling, extrusion equipment and other relevant process factors. Among them, the change of the size of the mold is very large, and the factors affecting the size of the mold are: the elastic deformation of the mold, mold temperature, mold materials and mold manufacturing precision and die wear.

(1) Choice of tonnage of extruding machine for aluminum profile

The extrusion ratio is a numerical representation of the mold to squeeze the difficult, generally speaking, the extrusion ratio between 10-150 is applicable. The extrusion ratio is less than 10, the mechanical properties of the product are low, the extrusion ratio is too high, the product is prone to surface roughness or poor angle. Solid profiles are often recommended to squeeze the ratio around 30, hollow profiles in about 45.

(2) Determination of the dimension of the shape

The shape dimension of extrusion die refers to the outer circle diameter and thickness of the mould. The shape dimension of the mould is determined by the size, weight and strength of the cross-section of the profile.

When calculating the size of the die hole, the main consideration is the chemical composition of extruded aluminum alloy, the shape of the product, the nominal size and allowable tolerances, the extrusion temperature, the linear expansion coefficient of the die material and the extruded alloy at this temperature, the geometrical features of the product cross-section, and the changes in the tensile straightening. The size of extrusion pressure and the elastic deformation of the die and other factors.

For a very large wall thickness of the profile, the difficult to form the thin-walled part and the edge angle area should be suitably enlarged size.

For large-scale flat-width thin-walled profiles and wall-panel profiles, the size of the truss section can be designed according to the general profile, and the size of the web thickness, besides considering the factors listed in the formula, it is necessary to consider the elastic deformation of the mould, plastic deformation and integral bending, and the distance from the center of the extruded tube. In addition, the extrusion speed,Aluminum profile there is no traction device, and so on the size of the mold hole has a certain impact.

The so-called reasonable adjustment, is in the ideal state, to ensure that each particle on the product cross-section should be at the same speed outflow mold hole.

As far as possible to use the symmetrical arrangement, according to the shape of the profile, the thickness of the different parts of the wall and the distance between the center of the extrusion tube, the design of unequal diameter belt. Generally speaking, the thinner the wall thickness of a section, the larger the circumference, the more complex the shape, the farther away from the center of the extruded tube, the shorter the sizing belt should be.

When using the sizing belt still difficult to control the flow rate,Aluminum profile for the shape is particularly complex, thin wall thickness, far away from the center of the part can be used to promote the flow angle or guide material cone to accelerate metal flow. Conversely, for those parts that are much larger in thickness or near the center of the extruded tube, the obstruction angle should be used to mitigate the flow rate. In addition, the flow rate of the metal can be adjusted by means of the process balance hole,Aluminum profile the process allowance, or the number, size, shape and position of the diversion hole.

Because the working conditions of the die are very bad, the mold strength is a very important problem in the die design. In addition to the rational placement of the mold hole, the selection of suitable mold materials, the design of reasonable mold structure and shape,Aluminum profile the accurate calculation of extrusion pressure and check the permissible strength of each dangerous section is also very important.

At present, there are many formulae for calculating extrusion pressure, but the modified Biell forest formula still has engineering value. The upper bound method of extrusion pressure is also applicable value, and it is simple to calculate the squeeze pressure by empirical coefficient method.

As for the mold strength check, should be based on the type of products, mold structure and so on respectively. The general plane mold only needs to check the shear strength and the flexural strength,Aluminum profile the tongue mold and the planar shunt mold need to check the shearing resistance, the bending resistance and the compressive strength, the tongue and the needle tip part also need to consider the tensile strength and so on.

An important fundamental problem in strength checking is to select the appropriate strength theory formula and to compare the exact permissible stress. In recent years,Aluminum profile the finite element method can be used to analyze the stress and the checking strength of the specially complicated molds.

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