SMM Exclusive: Promotion Of Aluminum Profile Production Technology For Mid- To High-End Doors And Windows

Aluminum profiles are products made of aluminum and other alloy elements. It is usually processed into castings, forgings, foils, plates, strips, tubes, rods, profiles, etc, and then is made through processes such as cold bending, sawing, drilling, assembling, and coloring. The main metal element is aluminum, with some alloying elements improving the aluminum material. Compared with architectural aluminum profiles used for ordinary doors, windows, and curtain walls, higher-end profiles used in products such as system doors and windows are also very common on the market. This article mainly takes mid-to-high-end system door and window profiles as an example to briefly introduce the application of mainstream technologies at the production end (casting, extrusion, and spraying) of mid-to-high-end architectural aluminum profiles and the selection and use of equipment.

On the raw material side, compared with ordinary doors and windows, mid-to-high-end system doors and windows generally use more aluminum rods billets of the 6063T5 grade. According to SMM, about 70% of mid-to-high-end aluminum profile manufacturers choose to equip themselves with melting and casting processes to produce aluminum rodsbillets. Among them, about 30% of the enterprises' aluminum rods billets are completely self-produced, and about 40% of the enterprises produce some of their aluminum rods billets by themselves, and while sourcing some aluminum billetrods with special components will choose to purchase outside externally.

From the perspective of the cost of the casting process alone, for mid-to-high-end profile products, the cost of self-produced aluminum billetrods is higher than the cost of externally sourced aluminum billetrods (including freight). However, the main reason why most companies still choose to produce self-produced aluminum billet rods by themselves is that . Aaluminum billetrods are the first step in the production of aluminum profiles and are the key to subsequent production steps. The company's sSelf-produced aluminum billetrods can allow a company to adjust the alloy composition of the aluminum billetrods by themselves to ensure that the composition is stable, laying a solid foundation for subsequent processes and improving the yield rate, thus reducing the total cost of aluminum profile production. In addition, self-produced aluminum billetrods can flexibly adjust output according to actual order volume. Compared with externally sourced aluminum billets, the risk of backlog of raw material inventory and occupying large amounts of funds is lower.

In terms of extrusion, since the aluminum billets for door and window profiles in mid-to-high-end systems mainly have diameters of φ90, φ128 and φ150, the tonnage of the extruders used is generally below 2000T, with 600T~1500T being the mainstream. In addition, in terms of technology, the "low temperature and high speed" production process is currently used more frequently on the market. This process plays an important role in improving the efficiency of a single extrusion machine.

In terms of coloring, there are mainly powder spraying, fluorocarbon spraying and oxidation electrophoresis processes. Electrophoresis is the application of electrophoretic paint to the cathode and anode. Under the action of voltage, the charged paint ions move to the cathode and interact with the alkaline generated on the cathode surface to form insoluble matter, which is deposited on the surface of the workpiece. The electrophoretic paint film has the advantages of full, uniform, flat and smooth coating. The hardness, adhesion, corrosion resistance, impact performance and penetration performance of the electrophoretic paint film are significantly better than other coating processes. Its disadvantage is that the color of electrophoresis is relatively single, and there are only a few colors (silver white, champagne, golden yellow, black, imitation stainless steel color). Secondly, electrophoretic colors are prone to color difference.

Fluorocarbon spraying refers to the multi-layer spraying process with three sprays (referred to as three sprays), spraying the base coat, topcoat and varnish and secondary spraying (primer, topcoat). It has good weather resistance, chemical resistance and corrosion resistance, and the price is relatively high.

The powder spraying process refers to using electrostatic powder into spraying equipment to spray which powders onto the surface of the workpiece. Under the influence of static electricity, the powder will be evenly adsorbed on the surface of the workpiece to form a powdery coating; the powdery coating is baked and leveled at high temperature Curing. It turns into coatings with different effects. The spraying effect is superior to the spraying process in terms of mechanical strength, adhesion, corrosion resistance, aging resistance, etc. Compared with fluorocarbon and electrophoretic processes, powder spraying has the advantages of high efficiency and energy saving (because it is a one-time film formation, and it can increase productivity by 30-40%, reduce energy consumption by about 30%). It has no organic solvent volatilization (no paint coating Toluene, xylene and other harmful gases), good coating properties and color diversity and make it very popular among mid-to-high-end door and window profiles. Powder spraying includes vertical spraying and horizontal spraying. The vertical spraying line has a larger production capacity and a higher degree of automation. It can handle a large amount of orders and produce standardized profiles. Compared with the vertical line, horizontal powder spraying is more flexible. It has higher reliability and relatively small investment, and is suitable for processing profile products with small order volume and customized types.