In the manufacture and converting of nonwoven fabric it is important to keep the fabric under control from side to side. There are four main methods to accomplish this:
- Unwind guiding
- Intermediate displacement
- Intermediate steering
- Rewind web guide
Unwind guiding is commonly used in slitting and converting. Intermediate displacement and steering are often used in printing and for narrow webs. Rewind guiding is the most common method used in nonwovens. It is used on the winders of even wide nonwoven lines to make well built rolls and to reduce waste due to edge trim.
All the methods use sensors to detect either the edge of the fabric or a line on the fabric. The sensor can use a laser, a jet of air. ultrasonics, or photo electrics. The displacement and steering systems use rollers to move the fabric. The unwind and rewind systems use hydraulic, pneumatic, or electric cylinders to move the actual unwind or rewind machine.