The soul of Delta Salotti sofas, namely the internal shafts, are produced with high-quality wood and subjected to strict tests about resistance and stability; according to the type of product, other materials take part of the construction of the supporting structures, such as steel, aluminium, expanded polyurethane and foam. In order to obtain an uniform resistance to weight-stress, the structures are completed with elastic straps, with different strength for the seats and backrests. Some models, instead of elastic straps, have steel springs, used especially in order to confer a great resistance and solidity to the sofa.
The frames of the seats, which are subjected to the greatest stress, are made with interlocking bands and angular sections of reinforcement, which make them sstable and non-deformable. On the frames of the seats are stretched the elastic straps of 7cm, in order to support the cushions and ensure an adequate suspension, balanced with the overall comfort of the living room. The straps are crossed with each other through a mixed process, manual and automatic, with the same degree of tension to ensure a great homogeneity, especially with regard to the weight distribution.