Milled wood is not curved – unless you bend it

Those who associate coffee house culture throughout the world with the name Thonet think of the legendary bentwood chairs – the origin of our corporate history. With his invention of bending wood into a form using steam and muscle power, Michael Thonet laid the cornerstone for modern furniture. In the 1830s he first experimented with veneer strips boiled in glue until he finally succeeded in developing “furniture of solid bent wood”. Today we are speaking of bentwood if solid bent wood is used in furniture production. At the time, bending solid wood was revolutionary, and it has not lost any of its fascination to this day. Professional wood benders produce a diversity of bentwood furniture in our Frankenberg facility. A total of 147 individual work steps are necessary to finish the classic 210 R.

1. Wood cut

First, a beech canticle is turned into a rod. Thanks to the short wood fibres, beech wood is very stable and especially suitable for the bentwood process. The fibre direction is of enormous importance for the bending process: if bent against the fibre structure, the wood will break. 

2. At full steam under high pressure

The wood is steamed at over 100 degrees Celsius. The material remains under pressure in the steam boiler for approximately six hours. Due to this pressure, the steam is forced into the wood until is it saturated. The high temperature makes the beech rod extremely elastic – the most important precondition for the subsequent bending process.    

__________________________________________________________________________________

3. Preparation of the bending process

The wooden rod is now placed into the bending mould by specialists. A metal strip fixed on the outer edge of the beech rod prevents the wood fibres from stretching on the outer radius. Without this support they would tear and the wood would break. 

4. From wooden rod to backrest

Now the bending begins: the benders turn both sides of the rod inward by 70 degrees with full power. To create the slight outside curve of the back legs, the ends of the rod are then slightly pulled against the bending direction. The material is then secured in the bending mould. For the backrest of chair 214, the famous Vienna coffee house chair, at least two benders are needed; the backrest of chair 209 even takes the effort of four specialists.

__________________________________________________________________________________

5. Drying

In order for the bent backrest to stay in its new form, the wood spends two days in a drying chamber in its bending mould. After this process, only a small amount of humidity is left in the wood, which is then removed from the mould.