Improving wet tensile strength of paper glass using PAE, CNF and CMC

Today, with the introduction of new additives and nanostructures, investigations have been widely focused on improving paper properties while decreasing costs. One of the paper wet strengths is Polyamideamine Epichlorohydrin (PAE) that using high amounts of it is costly and may cause some systemic problems such as adhesion. In order to reduce the consumption of this material and improve bagasse paper wet strength, cellulosic nanofibers (CNF) and carboxymethyl cellulose (CMC) were used and the best treatments with the highest wet strength introduced. To measure paper wet strength, first, handsheets were immersed in 25ºC distillated water for 10 minutes, then tensile tests done. In this study, 30 treatments were evaluated including separate and combined addition of CNF, CMC and PAE. Results showed adding these materials separately has lower influence on wet tensile strength, while adding CNF and CMC together with PAE significantly improved wet tensile strength of handsheets. One of the best treatments with higher wet tensile index was the combination of 3% PAE and 2% CMC, which kept 18% of dry tensile index of paper in wet state, while no sign of adhesion of materials on paper handsheet maker screen and cylinder was observed. In addition, the combination of 3% PAE and 1% CMC kept 16% of dry tensile index of paper in wet state. This treatment decreased suspension freeness less than the former one. Thus, it is introduced as the best treatment which increases wet tensile strength.