The production, from a filament tow or tows, of a staple sliver in such a way that the essential parallel arrangement of the filaments is maintained
Note : The two methods of converting most commonly employed are:
(a) crush cutting, in which the filaments of the tow are severed by crushing between an anvil roller and a cutting roller with raised ‘blades’ helically disposed around its surface, and
(b) stretch breaking, in which the filaments of the tow are broken by progressive stretch between successive sets of rollers.
If subsequently a top is required, further processes of re-breaking and/or gilling may be necessary and the whole operation is then often referred to as tow-to-top converting or conversion.
Textile Resource (http://www.textile.org.uk)