Sunday, July 29, 2012

The Production of Contemporary Furniture Using the Rotational Moulding Process

Many of the world's leading contemporary furniture brands, and most of them are Italian, use a process known as rotational moulding for the production of their chairs.

If you read about their products in their brochures or on their websites you will come across phrases like,"made from rotational moulded polyethylene", but do you ever wonder what rotational moulded means, or what is polyethylene? I did and this is what I found out.

The process of rotational method can be traced back to a British gentleman named R. Peters who in 1855 developed a better way of making artillery shells. His aim was to create hollow vessels with walls of an even consistency. He did this by pouring the molten metal into a mould that spun round on two spindles in a biaxial manner and subjecting the process to heat. As the process was developed new materials were treated in this way, and new products were developed. By 1910 this concept was used in the making of hollow chocolate Easter Eggs. By the 1920s plaster of paris was being subjected to this process to make household objects such as vases.

The development of plastics in the 1950s resulted in a range polymers (resins) that were ideally suited to rotational moulding. A whole new range of products began to be produced this way including dolls heads, road cones, marine buoys, and car interior parts such as armrests. The rotational moulding process itself was becoming increasingly refined using high velocity hot air systems in the heating process and allowing products to cool while still rocking in the mould.

The discovery of new plastics in the 1980s such as polycarbonate and polyester combined with the introduction of moulds made from stainless steel with aluminium added to improve the heat transfer capability, allowed designers and engineers to consider creating more ambitious pieces of furniture. The plastics most suited to the furniture industry were polyethylene, polypropylene, polycarbonate, and nylon. These were usually put into the mould in powder form, heated and rotated until the polymer had melted and adhered to the mould wall, then fan cooled, and finally removed from the mould.

This process was used in the production of kayaks, canoes, refuse bins, but most pertinently for the purpose of this article it was adopted by Italian brands such as Magis and Driade to make great design affordable. Designers such as Philippe Starck and Ron Arad were employed by the furniture manufactures to create great designs that could be mass produced by rotational moulding. This became a very successful business model and enhanced the reputation of both the designers and the brands. It made economic sense to employ the best designers because creating a mould was an expensive process, but if the design was a success the unit cost of producing a chair decreased as more were sold.

Furniture made this way are available at Including many designs from Magis Article Source: Article Source: