Piloting wet tensile strength development of polyamide-amine-epichlorohydrin wet strengthened nordic bleached softwood pulp paper by alkyl ketene dimer internal sizing

The results of recent laboratory-scale studies regarding the joint effects wet strengthening agent polyamide-amine-epichlorohydrin (PAE) and internal alkylketene dimer (AKD) sizing on Nordic bleached softwood pulp (NBSK) handsheets indicate that AKD increases strength PAE strengthened handsheets. boosting effect was long-lasting. At molecular level actual mechanism behind is unclear. present study examines if enhanced sizing, which potentially exploitable in practice, also occurs paper made by VTT’s Suora pilot machine. trials were done using a similar type NBSK same chemicals as studies. formed at 400 m/min hybrid dewatering mode (Fourdrinier + gap). Just studies, wet-strengthened resulted long-lasting increase strength. In accordance with laboratory trials, had no noticeable dry tensile pilot-made paper. only apparent difference to earlier observations an treated solely PAE.