Volumes of production
At present, production runs of about 1,000 parts are considered large, but mass-production is a possibility, with some automobile manufacturers starting to use the process on a larger scale.
Unit price vs. capital investment
High capital investment, mainly in tooling and material.
Speed
Depends on the material—some alloys can be formed in three to four minutes, while the structural alloys used in aircraft, for example, may need up to an hour to form.
Surface
Excellent surface quality.
Types/complexity of shape
This depends on the specific method you use. Bubble forming allows the greatest degree of complexity in shape, but with all methods the basic principle is about creating three-dimensional shapes from a flat sheet. Draft angles need to be considered in order for parts to be removed from the mold. Undercuts are not recommended.
Scale
Each method is suited to different scales and thicknesses of material, for example, using back-pressure forming, parts can be made up to approximately 48 square feet. Cavity forming can only process smaller sheet sizes, although these can be up to 3/8 inch thick.
Tolerances
Typically ±1/25 inch for larger parts.
Relevant materials
This process is specifically designed for use with what are known as “superelastic” types of aluminum. However, the diaphragm-forming method enables the processing of non-superelastic materials.
Typical products
A large market for this process is in the aerospace and automotive industries. Designers such as Ron Arad and Marc Newson have applied it to diverse furniture and bicycles. On the London Underground, architect Norman Foster used superforming to produce tunnel-cladding panels for Southwark station.
Similar methods
For plastic, vacuum forming (p.64), for glass, slumping (p.52), and for metal, look at the inflated stainless steel by Stephen Newby (p.76).
Sustainability issues
The process requires several stages of production, each of which uses significant amounts of energy through high heat and pressures. A significant amount of excess material is produced after trimming but can be recycled back into the process or used elsewhere. Additionally, when the formed product reaches the end of its lifespan it can be recycled into new products to reduce the use of raw materials. The nature of the shapes that are thermoformed means components can be nested during transportation, saving on bulk.
Further information
www.superform-aluminium.com
Free Internal Pressure-Formed Steel
Product |
Plopp Stool |
Designer |
Oskar Zieta |
Materials |
stainless steel |
Manufacturer |
Oskar Zieta |
Country |
Switzerland |
Date |
First exhibited 2009 |
The visual language of these stools refers to the soft forms typical of inflated latex, masking the fact that they are made from stainless steel.
This whimsical and playful process is a buoyant example of a traditional technique used in an unconventional way to produce creative and surprising results. It works like inflatable pool toys or armbands, but uses steel in place of plastic to create objects that are incredibly solid and strong. Oskar Zieta, the designer behind the process, calls it “FIDU,” which stands for free inner-pressure deformation (the letters correlate in his native German).
Two sheets of steel are laser cut to produce two pieces that are identical in shape. These pieces are then welded together along the edges by a robot to provide a water-and airtight seal. As the air enters, the sheets begin to deform and expand into a 3-D shape. The result is a light construction, which can be easily mass-customized at low production costs with well-established techniques.
This process, with Oskar’s many other sheet-metal-forming techniques, opens up new possibilities for lightweight structures and products that are incredibly strong and stable.
– Produces comparatively lightweight structures from a rigid, thin material
– Products are highly customizable.
– There are several stages of production (laser cutting, welding, forming), which increases lead times.