Strip guidance on the uncoiler
Quality during continuous strip processing
If a strip centre or strip edge guidance system is provided on the uncoiler, the uncoiler moves the coil, from which the strip is being uncoiled, transversally to the line axis and thus acts against lateral migration of the strip. Deviation of the strip from the reference position is detected by the sensing equipment and transmitted to the electronic gain control amplifier. The output of the amplifier continuously activates a control valve which moves the hydraulic cylinder of the uncoiler accordingly, so that the uncoiled strip is returned into the position preselected on the sensing equipment.
For control reasons, the sensing equipment should be located close to the strip. The high-frequency alternating light sensing equipment, which is protected against extraneous light, allows a maximum distance between the receivers and the light source of 4 m. For production lines with trimming shears installed immediately downstream of the deflector roll, we recommend that the uncoiler and the deflector roll are coupled mechanically or electrohydraulically. This has the advantage that guidance with a very high degree of precision is achieved when using a precise sensing system, e.g. a BMIH inductive strip centre sensing system.
In lines where the distance to the trimming or slitting shears is greater, an additional guide roller is installed upstream of the shears and connected to the coiler control.
