Bentwood

Bentwood is wood work which has been bent by means of a developed by Michael Thonet in 1830 procedure under steam. Bentwood, mostly maple or beech wood is especially processed to chairs.

From 1830 Thonet began with trying to manufacture of glued and bent wooden slats furniture. 1836 there was a first success with the Boppard laminated wooden chair. As of 1867, the company Jacob & Josef Kohn ran a campaign that Thonet should put aside his patent rights. Thonet in 1869 renounced his rights and Kohn took on as a result of the production of bentwood furniture.

Production method

Normally when bending timber breaks the outer side ( = tension side ). By the use of a tension band, the elongation of the outer zone is limited, but the inner zone ( = pressure area ) is more compressed. First, however, the lignin of the wood by steam or by boiling must be softened. After bending, the molded parts must be dried clamped ( locked against return molding ) in order to avoid a reset. The advantage of bending is that no loss occurs timber (as opposed to machining processes such as milling, etc.) and in spite of thin cross-sections and relatively small radii, a high strength of the briquettes is achieved.

In Bugholzverleimung thin layers of wood are glued together and then bent into a shape. This modern method allows seating swinging freely to construct and was used in Scandinavia.

Applications

Bentwood was used for the production of chairs, rocking chairs, sofas, piano chair, etc.. In the 20th century the process with Bugholzverleimung of Scandinavian designers such as Alvar Aalto, Bruno Mathsson and Yngve Ekström was resumed.