The production of aluminum alloy door and window profiles has four processes: ingot preparation, extrusion molding, heat treatment and surface treatment
1、 Casting preparation
The process includes batching, melting, casting, soaking and other main processes to form ingots with certain chemical composition and overall dimensions.
The prepared raw materials are melted in gas furnace or electric furnace. After melting, the melt goes through the static furnace, flow trough, flow plate and filter to the mold, and then water-cooled to form a certain shape of ingot.
In order to ensure the smooth surface of the ingot, magnetic casting or hot top casting method is used for multi-mode (multi mold) casting. Ingot soaking is to homogenize the metallographic structure of the casting state and dissolve the main strengthening phase.
Soaking is carried out in the soaking furnace. Soaking can improve the plasticity of ingot, increase the extrusion speed, prolong the life of extrusion die and improve the surface quality of extruded profiles.
2、 Extrusion molding
Extrusion molding is an automatic production line composed of ingot heating, extrusion, cooling, tension straightening and sawing.
The equipment on the production line includes induction furnace, extruder, discharge table, discharge conveyor, profile lifting and transferring device, cooling bed, tension leveler, storage platform, traction machine, sawing machine, etc.
The heating temperature of ingot is generally controlled between 400 ℃ and 520 ℃. If the temperature is too high or too low, it will directly affect the extrusion molding. Generally, single acting hydraulic press is used for extruder, and its tonnage is between 1200 tons and 2500 tons.
The diameter of the extrusion cylinder of the extruder varies with the tonnage of the extruder. The tonnage of the extruder is large, and the diameter of the extrusion barrel is also large.
The diameter of extrusion cylinder is generally in the range of 150 mm ~ 300 mm. The working temperature of extrusion tool is 360 ℃ ~ 460 ℃, and the extrusion speed is 20 m / min ~ 80 m / min. Extrusion tools mainly include dies.
According to the structural characteristics, the extrusion die can be divided into flat die, split die, tongue die and split combined die. The production of aluminum alloy door and window profiles are mostly flat die and split combined die.
The discharge table receives the profile from the extruder and transfers the profile to the discharge table.
Most of the discharging worktable is the horizontal bar transport type, and the movement speed of the horizontal bar is synchronous with the extrusion speed.
The cooling bed is mostly of walking beam type, and a considerable number of fans are installed under the cooling bed to ensure uniform cooling of the profile, so that the temperature of the profile is lower than 70 ℃ before straightening.
The tension leveler is equipped with twist jaw, which can be straightened while twisting. After the tension leveler is the storage table, which provides the profile to the sawing machine table, and the sawing machine cuts the profile according to the fixed length.
3、 Heat treatment
The aluminum magnesium silicon aluminum alloy used in aluminum door and window profiles is an aluminum alloy that can be strengthened. Through different quenching and aging systems, the mechanical properties of the profiles can be obtained. The aluminum door and window profiles are supplied by RCS, that is, the heat treatment is rapid cooling and artificial aging after high temperature molding.
4、 Surface treatment
The surface treatment of aluminum door and window profiles mostly adopts anodizing, which makes the surface of profiles silver white. Surface treatment can enhance the appearance of profile and prolong the service life of aluminum door and window profile.
The process flow of anodizing is as follows: loading → degreasing → water washing → alkali etching → warm water washing → cold water washing → neutralization and light releasing → water washing → anodizing → cold water washing → warm water washing → hole sealing → drying → unloading → finished product inspection → packaging aluminum door and window profile anodized film thickness shall not be less than 10 μ M.
The surface treatment of aluminum door and window profiles can also be done with coloring. Aluminum profiles with other colors can be obtained by natural oxidation coloring, electrolytic coloring and impregnation coloring.