Influence of drying process variables on the wet tensile strength of towel paper with the addition of polyamidoamine-epichlorohydrin (PAE) polymer

The tensile strength of paper towels with the addition of polyamidoamine-epichlorohydrin (PAE) polymer was tested. The papers were formed from a pulp consisting of pine and eucalyptus fibres in a 50/50 ratio. PAE was added to the paper pulp in an amount of 3.5 mg/g. The samples were pressed on a conventional press and dried on a drying cylinder. During the drying of the samples, the process parameters were changed, i.e., temperature (100 to 200 °C) and drying time (2 to 15 s). The drying conditions of the papers with the addition of PAE had a significant impact on the wet strength of the paper. The highest ratio of wet tensile index of the papers to dry tensile index in both directions, (MD and CD), was obtained for papers dried at 150 °C for 15 s. The results showed that with the increase in the dose of thermal energy supplied to the paper with the addition of PAE, its wet tensile strength increased. This applies to both the extension of the drying time and the increase in the drying temperature. Dry tensile strength tests of papers with the addition of PAE polymer showed that drying conditions were not of significant importance in that case.