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Abstract: In this work we present a mathematical model describing the coupled heat and moisture transport in paper. The model is solved numerically and the numerical solution is used to study the interdependency of the moisture and temperature distribution in paper. The results show that variation with temperature of the saturated water vapor concentration and the sorption isotherm parameters are both important for inducing moisture desorption. It is also found that for steep relative humidity ramps moisture sorption generates temperature increments that slow down the sorption process itself. The model is also used to study the moisture gradients in a paper sheet inside a printer from Océ Technologies, which contains a warm print surface. The results predict changes in moisture content of only 0.2%, which suggests that no deformations are induced on the printed sheet. [Copyright &y& Elsevier]

Abstract: This paper is concerned with the temperature field produced by a thermal printer head. Such heads are used to provide high quality prints of electronically stored images. In this system, a thin dye-layer, sandwiched between two copolymer sheets, is heated by a thermal head and dye diffuses into the receiver sheet producing a small dye-dot. The picture is made up of a large number of such dots. The basic aim is to determine the amount of dye which is eventually diffused into the receiver sheet when the heating is turned off and the system has cooled down. However, the amount of dye which diffuses into the receiver sheet depends on the temperature field because the diffusion coefficient is a sensitive function of temperature. In the thermal printer system, each head is heated by an electric current which is carried by gold leads. In this paper, we show that the heat loss through these leads has an important effect on the temperature field produced by the head and therefore, strongly influences the amount of dye transferred. [Copyright &y& Elsevier]

Abstract: This paper describes hybrid mathematical model which couples the mechanics of the mass/spring model to the acoustic wave propagation model for use in generating the acoustic signal emitted by complex structures of paper fibres under strain. A discussion of the coupling method is presented including remarks on the errors encountered intrinsic to the discretisation scheme. The numerical results of a vibrating rubber band and a vibrating paper fibre are compared to their experimental counterparts. The fundamental frequencies of the acoustic signals are compared showing a close agreement between the experimental and numerical results. [Copyright &y& Elsevier]