The most concrete basic idea of my development project began to germinate as early as 1988, after I had read article 46 in Puutekniikka magazine, which described the large-scale industrial 1D press drying of beech sawn timber used since 1962 by the Danish parquet giant Junckers Industrier A/S in the manufacture of solid wood parquet. It is carried out with heated plates that press the flat faces of the sawn timber. In the process, sawn timber with a moisture content of 80% dries to a moisture content of 1% and is further processed through heat treatment and stress relief, while its flat faces are straightened and densified and its bending strength increases. All of this takes place in two hours. The pressing temperature is 160 °C, the pressing pressure 12 bar and the reduction in thickness of the load-bearing parquet blanks, i.e. the compression, 20%.
The press-dried blanks are used to manufacture solid wood parquet, mainly beech parquet. Of the common parquet wood species, beech has the highest internal stresses and the greatest moisture movement.
If any product is required to have the highest level of dimensional accuracy, straightness and freedom from movement, it is parquet of every kind. Parquet is also produced almost exclusively from hardwoods, at least as far as the wearing surface is concerned. Hardwoods have higher internal stresses than softwood and the greatest moisture movement. No wonder the above-mentioned press drying technique has been needed and still is.
To reduce moisture-related and other movement, the world’s other plank parquet producers manufacture their products in an entirely different way, namely by gluing them together from three different layers of material.
Solidiwood technology is about supplementing the 1D hot pressing that has been in large-scale industrial use at Junckers for 62 years with 17 new profit drivers, already tested in laboratory studies and set out in the next section, WHY SOLIDIWOOD TECHNOLOGY.