The seven notes of Aluminum veneer in the design and bending process

According to "JGJ 133-2001 Metal and Stone Curtain Wall Engineering Technical Standard," while creating components in the aluminum veneer sector, the aluminum veneer should be curved around. The folded edge of the aluminum veneer not only serves as a connection but also as a reinforcement in the perimeter of the aluminum veneer, which serves as a strengthening role to prevent panel deformation, thus the folded edge is critical. Therefore, what factors must be considered throughout the aluminum bending process? This essay presents seven technical pieces of knowledge in this regard, and I hope you find them useful.

1. The degree of technical proficiency of the operating workers

The relevant operating workers must be very skilled in the operation of processing equipment, having received the relevant professional training before taking up the job. Aluminum veneer bending must be done with care to ensure its safety.

2. The specification size of aluminum veneer

Direction: Usually aluminum veneer manufacturers deliver raw materials for aluminum sheets into the factory in rolls; the common width varies from project to project but is mostly 1.5–2.4 m or wider. Aluminum veneer width should be given priority over specifications below 1.5 meters because this specification has the lowest price and the shortest delivery cycle. The plate width is too wide, not only to increase the price but also because with the increase in size, its deformation capacity increases, which is easy to cause surface deformation of the workpiece and a decrease in flatness after installation, among other consequences.

3. Determine the aluminum veneer plate seam

The curtain wall of the building can have a certain displacement capacity for the main structure, so the splicing between aluminum veneer plates for the curtain wall often uses slit processing. The aluminum veneer façade is disconnected from the slit into independent plates and installed separately. The treatment of a slit is mostly in the form of an open slit, glue, plugging tape, etc. The arrangement of the slit is determined by the size of the divider.

The width of the slit depends on the visual effect, installation process, sealing requirements, etc. Visually, the width of the slit should be consistent with or similar to the architectural style. Too small a slit can easily cause installation difficulties and the tearing of sealant due to insufficient expansion and contraction. The plate seam is too large, the sealant dosage increased, and it is easy to blister. Most of the common aluminum veneer glue seams are between 8mm and 18mm.

The depth of the plate seam is generally greater than the length of the aluminum plate's folded edge. The shallow seam should consider whether it can meet the minimum glue thickness required by the specification and whether the adhesive strip can be installed. And when the slab seam is deep, the operating range of the installation tools should be considered, and the specific depth needs to be determined by combining the actual installation form and conditions.

The board seam should also take other factors into account, such as the installation sequence and the installation tools and processes.

4. The size of the folded edge

The minimum value of aluminum veneer bending needs to consider the size of the bending machine fixture; if the bending edge is too small, the fixture cannot hold the aluminum veneer to complete the bending. Commonly used equipment in the bending of the minimum bending value of 9.5mm + plate thickness size, that is, the thickness of 3.0mm aluminum plate minimum bending size of 9.5mm + 3mm = 12.5mm.

The maximum size of the folded edge should refer to the aluminum veneer manufacturer's signed "aluminum curtain wall purchase and sale supply contract" document. Generally speaking, the folded edge size of aluminum veneer in a certain area belongs to the scope of free production of aluminum veneer manufacturers, not counted in the cost. Larger than this value is regarded as the panel and not the folded edge, the conventional folded edge free value of 20mm.

5. The length of the folded edge

The commonly used aluminum veneer bending machine size is 6m, which determines the bending length is not greater than 6m. If special circumstances require the processing of workpieces larger than 6m, the planing groove treatment should be considered, that is, the groove is cut in the aluminum plate and bending is done by hand. Aluminum veneer in the case of large plate surfaces is prone to deformation, and the strength of aluminum veneer decreases after the planing groove, the use of planning groove way bending needs to be strictly precision calculation.

6. Plane groove bending

In the case of the bending machine can not achieve bending, such as extra long or tool space is not enough, sometimes need to consider planning groove bending. Planing slot bending is to remove part of the aluminum veneer material at the bending place, and then bend by hand. This way can make up part of the shortcomings of the bending equipment, but there are also many defects. Due to the uneven force applied during manual bending, the phenomenon of uneven bending may occur. Removing part of the plate, the strength of the bending place is reduced, which needs to be recalculated when using. The outer rounded corners of the aluminum sheet after bending are significantly different from the size of non-planing groove bending. We take a 3.0mm aluminum veneer as an example, the normal bending outer corner R≈4.5mm, and the planning groove bending outer corner R≈1mm.

7. Folded edge rounding

When bending an aluminum veneer, it is pressed on the inside and pulled on the exterior, resulting in rounded corners with uneven radii on both sides. The design normally takes into account the aluminum veneer bending material homogeneity, strength, and the radius of the corner of the center line of the aluminum plate is equal to the plate thickness. Consider bending 3.0mm aluminum veneer 90°, the center line rounded angle R in 3, outside the male angle R outside 3 + 3/24.5, inside the negative angle R3-3/21.5. This information is provided for reference purposes only; real sizes may vary due to processing equipment, technology, worker skills, and other variables.