Roller crosses/guides are used in the processing of endless material between the spool or coil, straightener, pull-off unit or processing machine. Their function is to guide and support the product to be processed.
The number and the arrangement of the roller crosses/guides in the material flow system are selected so that
- sagging of the material is prevented,
- sharp edges and deflections with small radii do not damage the surface of the material,
- the endless material enters the next apparatus or machine in central position.
The diversity of roll guides results in a wide range of different applications. Which roll guide is selected will depend on the particular requirements. Roll guides are available as rigid and adjustable types. Adjustable roll guides are used when dimensions change and when exact positioning of the material is essential.
Centrally adjustable roll guides are suitable for a range of dimensions. The center of the material is retained even when dimensions change. The material itself does not have to be adjusted for it to enter the line centrally.
Some roll guides are designed to completely enclose the material while they guide it. Others are open on one side for better insertion of the material.
Roll diameter, roll material and clear widths depend on the dimensions and geometry of the material. Burnished and hardened steel rolls are used e.g. for firm materials. Softer rolls made of PETP can be used for sensitive surfaces. The following basic types of roll are available:
- with chromium-plating
- hardened (up to 64 HRC)
- with rubber coating
- with ceramic coating
- rolls made of PETP, PVC or polyamide
See Also
Adapted from “"We do it straight" — Wire Straightening”, p. 135 (ISBN 3-00-005897-4).