2. Characteristics of these families

Table 1 summarizes the characteristics of each.

Each company has its own technologies in each of these categories, and its own specific implementation methods. Techniques are constantly evolving. It's useful to categorize them, but it would be pointless to set them in stone today.

The techniques listed in table 1 have been industrially tested or have been the subject of conclusive trials. The number of references indicated, corresponding to projects carried out by UPDS member companies and which can be declared, should therefore be considered as a minimum.

It is difficult to break down the operations carried out according to technique, as more often than not, several processes are implemented simultaneously....