Effect of Drying Conditions on the Development of Binder Strength in Double Coated SBS Paperboard

Recent equipment additions to The Centre International de Couchage (CIC) pilot coater allow web temperature monitoring throughout the coating, drying and in-line hot soft calendering (HSC) process. This new capability can be used to determine dwell times when the coated surface is above the glass transition (Tg) temperature of the latex binder being run. Thus the minimum drying process conditions can be determined that fully cure today’s new high strength paper coating binders. Optimum surface strength and coating structure for print quality can be found while minimizing the binder and costly opacifying pigments. This allows mills to achieve the best economics while producing high quality coated paper and paperboard. This is an important consideration for many mills whether running paperboard weights, coated freesheet or light weight coated papers. Mill web temperatures versus time interval can be audited against known optimum drying conditions to insure optimum paper qualities and costs.