Acoustic Emission during the Tensile Straining of Paper from Hardwood Pulp

Abstract

Acoustic emission (AE) that occurred during tensile straining of paper from hardwood pulp with and without dry strength resin was measured and analysed to investigate the process and mechanism of tensile deformation up to maximum load. Maximum amplitude distribution of the AEs that occurred during the straining manifested some changes of micro failures with increases in beating degree and addtion level of dry strength resin. The increase in bonding area by beating and increase in specific bonding strength by addition of the resin cause an increase in failure of strong fiber bonds. Although almost all of micro failures that occurred during the straining up to maximum load are attributed to those of weak fiber bonds, some strong fiber bonds and/or fibers themselves fail just before maximum load for the handsheets from beaten pulp. With addition of the resin, strong fiber bonds and fibers themselves begin to fail even in mid of the plastic deformation.