Temperature control of multizone heated rollers

Heated press rollers are used to give tactility and gloss to papers, fabrics, nonwoven fabrics, films and so on. The surface temperature of the heated roller and its uniformity are especially important. Existing heated rollers have surface temperature profiles up to 10degC deviations, causing listing in fabrics. In order to suppress the surface temperature deviation to 1degC, we propose a heated roller system having multizone electric heaters and heating oil within the steel roller. The heated roller temperature control system is ill-conditioned. Because the controller performance is very sensitive on uncertainties in the model and disturbances, very accurate identification and elaborate controller design are required. For this, recent sequential relay feedback autotuning methods are applied for identification and controller design. Experimental results are given.