Quality Improvements in Paper Coating Process Through Application of Advanced Sensor and Process Automation Technologies, 2005 European PLACE Conference

This paper presents case studies of significant improvements in roll quality across the full-width multilayer coatings on paper substrates, resulting from an on-line gauging system incorporating advanced sensor and process technologies. Accurate on-line discrete layer measurement across the full coating width is essential in paper coating processes for manufacture of consistently high quality rolls with minimal waste from edge-trims. High Resolution Full spectrum Infra Red (HR-FSIR) sensors deliver the performance unmatched by any other currently available sensor technology. These sensors measure the multi-layer coatings to within 8 mm of the coating edges on substrate or foil, at high scan speeds. Advanced control algorithms incorporating Accelerated Time Response (ATR) enable Automatic Profile Control (APC) of the extrusion coating dies to rapidly and precisely control the profile of the various coating layers. The resultant full-width gauge uniformity has profound effect on wound-roll quality and subsequent downstream operations such as slitting.