I did some further research into alternate methods of producing the seat form, and how this would be implemented into the design process. The seat form, on a manufacturing level could be made from a light aerodynamic plastic and rotational moulded to produce a portable, yet stable light plastic shell that has the majority of the same properties as wood, allowing the joining and upholstering process to remain virtually the same. Similarly the curved form of the seat could be produced through the process of PU foam moulding , that would produce a more ergonomic product, and would reduce the of foam padding applied through the upholstery process.
Rotational moulding involves a heated mould filled with a certain amount of material. The mould is slowly rotated, normally around two perpendicular axis which causes the heated material to soften and disperse, evenly, in a layer along the walls of the mould. The mould continues to rotate so as the material will stay in shape, in an even layer, until the material has cooled to avoid any sagging or deformation to the mould.
JSC Rotational Ltd, in Worcestershire, England use clam shell moulding machines to produce mould components up to 3.1m long and 2m wide, the materials currently processed are LDPE, MDPE, HDPE, PP, Nylon, and cross-liked PE, however they can also multi shot with PE foam.
Reaction Injection Moulding is the process of which PE foam is used cast, the process is similar to injection moulding except thermosetting polymers are used. This type of casting can produce strong, flexible, light-weight parts with quick cycle times in comparison to the likes of vacuum cast materials.