When irregular profiles are needed, the liner is made from a sheet of K-100 steel on which there is mechanized the form wished by means of court by thread. Of this form a solid liner is obtained from the only piece that borders each of the alveoles of the mould. These liners are made separately and are assembled supported on the frame by means of moored screws. They can be made with or without eyelash. If the latter is necessary, a copper is used by the wished form and a process is carried out of electroerosion to generate the eyelash.