A profile often contains various built-in features, including openings, screw channels, cooling fins, clamping openings, etc. During bending, force is exerted on the fragile cross-section and the complex cross-section can become distorted and functions can be lost. An aluminium profile also often has an aesthetic function, meaning it is important that the surface is not damaged too much during bending.
We will advise you during the design phase of an extrusion on the bending ability of a profile, without the cross-section being distorted too much, or the surface being affected. Kersten has modern bending and processing machines and a team of expert employees. In a separate, clean environment aluminium profiles are bent, cut to size and machined. This is how we deliver your semi-fabricate ready for assembly.
There are various methods for bending aluminium. Kersten performs the following bending techniques:
The most suitable technique depends on: the cross section of the profile, the desired radii, the bending direction, the alloy and the hardness condition of the material
Rolling is an important technique when it involves preparing aluminium for various applications. By moving the profile along three adjustable rolls, the profile is gradually formed into the desired shape.
The rolling process significantly increases the strength of the properties and structure of the aluminium. The machine settings do not have to be adjusted if another radius has to be bent, which results in considerable cost savings.
Rolling is an ideal technique for (large) profiles and with various radii and complex cross-sections. It is the most flexible and cost efficient bending method. Standard profiles are bent with tools that are often already available. If special tooling is required, we make customized tools in our in-house tool shop.
Kersten has become specialized in 3D bending. In addition to two dimensional bending, a third dimension can be applied in the same rolling operation, such as a rise or twisting.
Stretch bending originated within the aviation industry, but it is now also widely used for architectural, machinery, and automotive applications.
It is a very precise bending method in which the material surface remains in perfect condition and the diameter is distorted minimally. It is ideal, for example, for aluminium façade profiles, tent profiles and aerofoils, where the visual aspect of the application is very important.
A special stretch bending machine is used for this bending process. This firmly clamps the profile at both ends, tensions these and then pulls them back, around a mould.
In contrast to rolling, the profile does not come into contact with the machine, whereby the surface of the material remains in perfect condition. The constant tension on the profile cross-sectional ensures deformation is kept to a minimum.
When rolling a (thin walled) profile in a small radius, there is an increased risk of tearing and straining. In order to prevent this, the profile can be bent by means of mandrel bending.
A special CNC mandrel bending machine is needed for this technique and it requires product specific equipment to limit deformation of the cross section to an absolute minimum.
After creating special equipment, the mandrel bending process is accurate, fast and delivers constant quality. This makes this bending method particularly suitable for medium sized and large series.