Confocal laser scanning microscope imaging of network changes in unbeaten handsheets under in-plane tensile elongation

A new method of observing in-plane tensile deformations in paper has been established. It uses a miniature tensile tester which can be placed under a confocal laser scanning microscope. This method involves collecting time lapse confocal microscope images within the structure of a notched paper specimen. The image data can either be viewed individually or sequentially as a 'movie', By observing sequential frames collected during the sub-fracture, fracture and postfracture behaviour of the fibrous structure, valuable information regarding the role and interaction of fibres and their interfibre bonds can be obtained. These image sequences can also be correlated with the corresponding load elongation curves to provide a basic understanding of the effects of loading on the network structure of handsheets, Three different unbeaten kraft pulps prepared from Eucalyptus globulus, E. regnans Birch are compared.