Calendering of wood containing paper: A laboratory study of temperature, moisture and pressure effects on fibre wall damage

Abstract

The present thesis refers experimental and theoretical studies of the calendering process making use of the pendulum device as a means to simulate the roller calendering. The main task has been to clarify characteristic feature of the device in its capacity to simulate the calendering process with rollers. Measurements are made to enlighten the dependency of the paper characteristics gloss, smoothness and density by the running conditions as nip load, dwell time, roller temperature and moisture content of the paper. Furthermore, the deformation of the fibres and the thermal conduction in the paper during the compression are studied. Finally, an experimental and analytical study of the heat transfer between the hammer and the paper specimen is made. The results are compared with results from roller calenders in the extent they are available in the literature.