Considerations for Achieving Superior Roll Geometry
Whether you are winding sheeting, regular or gusseted tubing, it’s important to maintain excellent roll geometry. A number of important factors must be considered to achieve superior roll geometry. These factors include: effective gauge randomization of the incoming film (see MacroLetter-Winter 1995); overall winder design and precision machining of main side plates; precise alignment of winding drum, idler rolls, cut-over mechanism, etc.; correct air shaft specification to avoid deflection; precise control of winding tensions through use of AC vector or DC drives with load cells; precise control of contact pressure on winding shaft and ability to run with low winding tensions; discrete isolated tension loops for slitting and winding; perform final slitting, as close to the wound roll as possible; effective web-tracking control through use of offset pivot web design guide in the tower pneumatic (or hydraulic) side-lay guidance of the winder itself.
Other enhancements, such as gap winding and centre assist, can greatly improve roll geometry for very thin, tacky or slippery films.
