Method for spreading a tow of textile non-braided filaments, preferably chemical or inorganic filaments

A method for spreading a tow of textile filaments, comprising the following steps:

• providing a tow of textile filaments placed side by side and mechanically unbound, the tow extending along a main direction and having a section transverse to said main direction with a predetermined thickness and a predetermined width of at least 1 cm;
• feeding the tow along a travel path;
• spreading the tow in order to increase its width and reduce its thickness, defining a spread tow;
• wherein the step of spreading the tow comprises:
• immersing the tow of textile filaments in a bath;
• generating in the bath a sequence of transverse waves crossing the tow transversely to the main direction in order to translate and place the filaments side by side, thereby permanently spreading the tow;
• extracting the spread tow from said bath;
• wherein the tow entering the bath and/or the spread tow extracted from the bath is/are unsized;
• wherein the step of generating the sequence of waves comprises:
• feeding the tow along the travel path on a support provided with a plurality of through-holes;
• generating, alternately, a succession of first waves crossing the tow in a first direction and a succession of second waves crossing the tow in a second direction opposite the first direction;
• both the first direction and the second direction being transverse to the main direction and to the width of the tow;
• wherein the generating of the first waves comprises pumping a liquid exiting the through-holes along the first direction;
• and
• wherein the generating of the second waves comprises sucking up a liquid entering the through-holes along said second direction.