No abstract

Calendaring is an important operation in pulp and paper mill, with an objective to increase the smoothness or reduce the roughness of paper. Bypassing calendering operation in paper machine, paper of desired quality cannot be produced. In the present investigation, a nip mechanics model for supercalendering has been developed by expanding Meijers nip mechanics model up to fourth term, and using this model the effect of additional fourth term and various design and process parameters on results of supercalendering has been discussed using the data taken from paper industry.

In this paper, the analytic solution of one-dimensional heat conduction equation is obtained by means of new homotopy perturbation method. This method is effectively applied to obtain the exact solution for the problems on hand. Some problems related to one dimensional heat equation have been discussed, which reveals the effectiveness and simplicity of the method. Numerical results have also been analysed graphically to show the rapid convergence of infinite series expansion.

Calendering is well known operation in which a material is run between rolls to thin it in to sheets or to produce smooth or glossy finish. An attempt has been made in this investigation to remove the drawbacks in the model of Meijer's and applicable directly to soft calendering, also to make nip mechanics model generalized and applicable, So that it can be applicable where there is roll to roll or roll to plate contact. Also the effect of various design and process parameters on results of soft calendering has been discussed using the data taken from paper industry.

Calendering is a smoothening process at the final stage in textile industry, where fabric passes through the nips formed by two or more rolls in contact. The material used for making of rolls varies for different types of calenders. Depending on the quality of fabric required these rolls are hard or soft and can be heated to certain temperature, using induction process, hot water passage or heated oil passage inside the rolls. In rolling calendering process, fabric is pressed between two or more rolls, where nip is formed by the combination of alternate hard and soft rolls. In this paper effect of roll temperature and bonding time on fabric temperature has been discussed using single nip rolling calender, when fabric is inside the calender nip formed by hard and soft rolls having different temperatures using one dimensional unsteady state heat conduction equation.