No one else has been able to supply these 3D-formed panels
3D-Metal Forming BV, part of Van Campen Aluminium in Lelystad, has scooped a very special project for Qatar. It concerns the supply of 3D-formed panels for an exceptionally attractive building, consisting entirely of pure 2 mm stainless aluminium. The required elements could not be obtained from any other source in the world. Because of its exclusive production method - recasting materials through explosions - 3D-Metal Forming is the only enterprise able to provide these panels. Substantial sums of money, related to the degree of complexity of the project, of course, are involved in this exceptionally complicated order. Van Campen Aluminium starts the explosive recasting process with the production of master moulds from solid aluminium blocks, using the 5 axis Handtman finishing centre. This allows for the tolerance to be as small as one tenth of a millimetre. The 3D-Metal Forming explosion technique is subsequently used to shape the panels as required.
Using explosives to create refined wall panels may sound like a paradox. However, today we can see this technique being applied more and more. For instance, in recent times 3D-Metal Forming used this technique for the outside walls of the Castellum Theatre in Alphen aan den Rijn, designed by architect Dirk Jan Postel of Kraayanger Urbis in Rotterdam. The outside wall of this theatre consists of innovative, corrugated sheets. An exploded aluminium panel has been developed, inspired by wavy patterns created through receding water on the beach, called 'Desert Storm’. This technique - the so-called explosion forming - is no revolutionary development, but has not been used in the building industry until recently, especially for creating complex dual-curved outside wall elements. Explosion forming allows for the production of complex and dual-curved shapes in a relatively simple manner. Just about any type of metal, such as aluminium, steel and stainless steel, as well as nickel and titanium, can be moulded by way of explosion forming.
The technique can be particularly useful for creating dual-curved panels and adding a relief to plain sheets. For instance, the corner sections of ING head office in Amsterdam, by Meyer & Van Schooten architects, have been made with the help of explosion forming. Another example is the dual-curved panels of the roof of the Haarlemmermeer Pavilion by Asymptote Architects. Castellum Theatre in Alphen aan den Rijn, but also ING head office in Amsterdam and the Haarlemmermeer Pavilion by Asymptote Architects.
Indirect explosion form
This form is called the indirect explosion form, in which the blank has been put into a mould and a vacuum is created in the space between the mould and the blank. The entire unit is subsequently submerged into a fluid bath. The explosives are lowered into the fluid above the blank and detonated, resulting in the blank being forced into the mould at a very high speed and giving it the required shape. Indirect explosion forms are usually created in vessels filled with water, but other fluids can also be used. Large objects of up to ten metres long can be created in one go and solid blanks of up to 60 mm thick stainless steel can be formed. That is seen as two major advantages of explosion forming. Fewer follow-up treatments are required, causing less stress to the metal surface. Anodised or varnished metal blanks can also be reshaped beforehand. This will result in lower overall production costs than in the case of other remodelling techniques, such as deep drawing, pressing and the like. Explosion forming is particularly ideal for producing prototypes or small batches, but larger batches cause no problems either by moulding several blanks simultaneously.
Text: Bert Heijnen