Connecting aluminum panels: the core link to ensure the safety and stability of curtain wall systems

Aluminum veneer panel connection is a key component of the aluminum veneer curtain wall system. Its connection method and construction quality directly determine the structural safety, stability, and service life of the entire curtain wall. It not only serves as a "bridge" to secure the aluminum veneer to the building structure, but also must ensure multiple functions, including earthquake resistance, wind load resistance, and waterproofing. It is a crucial and essential step in aluminum veneer curtain wall construction.
1. Core Definition of Aluminum Veneer Connection
Aluminum veneer connection specifically refers to the technical process and system combination used to securely connect processed aluminum veneer panels to the building's main structure (or keel frame) using various connectors, fasteners, and auxiliary materials. Its core value lies in integrating separate aluminum veneer components into a cohesive curtain wall system, while also adapting to structural deformation and resisting external environmental loads, ensuring that the aluminum veneer panels remain free of fallout, deformation, and leaks over long-term use.
2. Main Connection Methods for Aluminum Veneer Panels
The connection method for aluminum veneer panels should be selected based on the application scenario, panel size, building structure, and load requirements. Currently, the mainstream connection methods can be divided into three categories. 1. Dry Hanging Connection
Dry hanging connection is the most commonly used connection method for exterior aluminum veneer panels. Its core feature is to hang the aluminum veneer panels on the keel using metal connectors, maintaining a certain gap between the panels and the wall.
Connection Principle: Mounting holes are reserved at the folded edges of the aluminum veneer panels. They are then connected to the vertical and horizontal keels using connectors such as angle brackets and bolts. The panels are sealed with adhesive strips or sealant.
Applications: Suitable for high-rise building exterior walls, large-span curtain walls, and public buildings requiring high construction precision. It is particularly well-suited for exterior wall insulation and ventilation requirements.
Key Advantages: Flexible installation and ease of maintenance and replacement; a cavity is left between the panels and the base layer, effectively relieving thermal expansion and contraction stresses and providing excellent earthquake and wind resistance.
2. Welding Connection
Welding connection involves directly welding the aluminum veneer panels to the connectors (or keel). Post-welding polishing and anti-corrosion treatment are required. Connection Principle: Argon arc welding is performed on the aluminum veneer's folded edge or pre-set reinforcement ribs with steel or aluminum connectors to create a rigid connection between the sheet and the frame.
Applications: Mainly used for interior decoration, small curtain walls, or special-shaped aluminum veneer panels (such as curved or irregularly shaped pieces), as well as in areas where extremely high connection strength is required.
Key Advantages: High connection strength and excellent structural stability; adaptable to the fixing needs of complex shapes, minimizing exposed connectors and enhancing the overall appearance.
Precautions: The welding process will cause thermal deformation, requiring strict control of welding temperature and process. Anti-corrosion treatment is required after welding to prevent rust at the weld points, which may affect the service life.
3. Adhesive Connection
Adhesive connection uses a special structural adhesive or binder to directly adhere the aluminum veneer to the base wall or frame. In some cases, a small number of fasteners may be used for auxiliary fixing.
Connection Principle: Structural adhesive is applied to the back of the aluminum veneer or the surface of the base, and the adhesive layer is used to secure the sheet. Screws are used to reinforce the edges of the sheet as needed, forming a combined "adhesive + mechanical" connection. Applicable Applications: Primarily used for interior walls and ceilings, where wind pressure is not a concern or the load is minimal, as well as for renovations of older buildings with relatively good base conditions.
Key Advantages: Fast installation, eliminating the need for complex fastener installation; no exposed fasteners, resulting in a clean, simple appearance, ideal for minimalist decorating.
Precautions: Highly flat base surfaces are required, requiring the base to be cleaned of impurities before bonding. Standard structural adhesives must be used to ensure bond strength and aging resistance, minimizing the risk of subsequent detachment.
III. Key Components of the Connection System
The aluminum veneer connection system is comprised of multiple core components, each of which directly impacts the quality of the connection.
1. Connectors
Connectors are the core intermediary components that connect the aluminum veneer to the keel. Common types include brackets, hangers, and brackets.
Main materials include aluminum alloy or stainless steel, requiring sufficient strength and corrosion resistance.
Select appropriate specifications based on the size, weight, and load requirements of the aluminum veneer to avoid safety hazards caused by undersized connectors. 2. Fasteners
Fasteners are used to secure connectors to the keel and to the aluminum panels. They primarily include bolts, screws, and rivets.
Stainless steel fasteners are preferred for exterior curtain walls to prevent rust and corrosion; galvanized or aluminum alloy fasteners can be used for interior applications.
The tightening torque must be controlled during installation. Too loose a fastener can cause the panels to loosen, while too tight can cause them to deform or strip threads.
3. Sealing Materials
Sealing materials are used to fill gaps between aluminum panels to prevent water seepage and air infiltration. They primarily include sealants, foam strips, and adhesive strips.
For exterior applications, use a weather-resistant silicone sealant that is UV-resistant, age-resistant, and resistant to high and low temperatures.
During sealant application, ensure that the joints are full and continuous to avoid air bubbles or breakage, ensuring a waterproof effect.
4. Keel Frame
The keel frame is the basic support structure for connecting aluminum panels. It consists of vertical and horizontal keels and is typically made of steel or aluminum alloy. The specifications and spacing of the purlins must be determined based on structural calculations of the building height and wind loads to ensure sufficient load-bearing capacity.

During installation, the purlins must be vertical and flat to provide a stable base for the aluminum veneer connections.

IV. Key Points in Connection Construction

Aluminum veneer connection construction requires strict adherence to standardized procedures and careful control of key steps to ensure the safety and stability of the connection system.

1. Preliminary Preparation: Accurate Positioning and Measurement

Before construction, the purlin installation position and elevation must be accurately measured and laid out according to the design drawings to ensure that purlin position deviations are within acceptable limits.

Inspect the machining accuracy of the aluminum veneer hems and mounting holes to ensure they match the dimensions of the connecting components to avoid installation difficulties caused by machining errors.

2. Installation Process: Control Precision and Force

The purlins must be installed with a vertical deviation of ≤3mm/meter and a flatness deviation of ≤2mm/meter to lay the foundation for subsequent aluminum veneer connections. When installing aluminum veneer panels, adjust the panel position to ensure uniform joints. When tightening bolts or screws, use a torque wrench to control force and avoid overtightening.
3. Anti-corrosion Treatment: Extending System Life
Insulating gaskets should be installed at points where different metal materials come into contact (such as steel keels and aluminum alloy connectors) to prevent electrochemical corrosion.
Welding areas should be cleaned of weld slag and coated with anti-corrosion paint or passivated. Exposed fasteners should be coated with sealant to prevent rainwater erosion.
4. Sealing: Ensuring Waterproofing
Before applying sealant, remove dust and impurities from the panel joints. Apply masking tape to ensure a smooth joint. After applying sealant, scrape and remove any excess sealant.
Foam strips should be installed at the bottom of the panel joints to prevent direct contact between the sealant and the substrate, ensuring uniform joint depth and improving sealing effectiveness.
V. Common Connection Problems and Solutions
During the use of aluminum veneer panels, various problems are prone to occur at the joints, requiring targeted solutions. 1. Loose panels and unusual noises
Causes: Loose fasteners, improperly selected connectors, deformed keels.
Solution: Regularly check and tighten loose fasteners; replace undersized connectors; if the keel is deformed, partially dismantle and readjust or replace the keel.
2. Leaking joints
Causes: Cracked sealant due to aging, incomplete joints, improper installation of foam strips.
Solution: Remove expired sealant and reapply weatherproof sealant; fill in incomplete joints; adjust or replace foam strips to ensure the required joint depth.
3. Corrosion at joints
Causes: Lack of anti-corrosion treatment, corrosion-resistant fastener material, or seal failure leading to rainwater intrusion.
Solution: Derust and polish corroded areas, reapply anti-corrosion paint, replace fasteners with corrosion-resistant stainless steel, and repair the sealant to prevent further water intrusion.