Contaminant transfer during the processing of thick three‐layer food packages with a recycled polymer between two virgin polymer layers

Abstract

Studies are made on food three‐layer packages, where a contaminated recycled polymer layer is located between two virgin polymer layers. As the thick food packages are made by pressing the polymer layers in a mould kept at around the melting temperature of the polymer, the process is thus rather complex with heat transfer and contaminant transfer. Heat transfer is controlled by conduction through the package with a high coefficient of heat transfer in the mould, and conduction through the package and free convection at the surface during the cooling period in motionless air. The contaminant transfer is controlled by diffusion through the polymer with a temperature‐dependent diffusivity. A numerical model taking into account both the heat and mass transfer is built in order to resolve the problem. Various parameters appear of interest, such as the conditions of the processing with the temperature of the mould and time in the mould, the thicknesses of the polymer layers. Two types of sandwich are considered with different thicknesses for each layer. The profiles of concentration of the contaminant are obtained through the polymer packages.

Citation

Perou, A.L. and Vergnaud, J.M. (1998), "Contaminant transfer during the processing of thick three‐layer food packages with a recycled polymer between two virgin polymer layers", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 8 No. 7, pp. 841-852. https://doi.org/10.1108/09615539810226175