COST SAVING CONCEPTS FOR PRODUCTION OF HIGH QUALITY COATED PAPERS - PART 2: BLADE-BLADE COATING SYSTEMS

摘要

This paper presents a cost and quality optimization approach in double coating. The concept is based on applying higher precoat weight than usual at very high solids. High color concentration results in a faster immobilization of the coating, thus allowing binder reduction. Moreover, better coverage and uniformity of the paper surface are obtained, enabling a substantial reduction of the more elaborate and costly topcoat. The shift in coat weight distribution means significant cost savings by applying a higher proportion of the simpler and less expensive precoat. The use of a novel latex technology in the topcoat provides adequate ink-coating interaction.It is demonstrated that the high solids content in the precoat, enabled by a reduction of low solids components in the color, has a positive impact on coating strength and other properties. Based on pilot coater work and mill trials, this concept is compared with the current common practice in terms of final paper characteristics and coater runnability.Cost savings due to a higher proportion of the less expensive precoat are complemented by a reduced drying energy demand, which either further adds to the cost savings or translates into increased coater speed in case of drying limitations.Quantification of the related production cost (coating formulation and drying energy) shows a significant savings potential for the proposed concept.