An experimental study on infrared drying kinetics of an aqueous adhesive supported by polymer composite

The infrared drying of an aqueous polymer emulsion spread on a thin composite flat film is experimentally studied. The composite film is composed of polyamide fibers supported by a poly(vinyl fluoride) film. The aqueous polymer is an Ethylene Vinyl Acetate emulsion playing the role of adhesive. It is spread over the film with a low thickness, about one hundred micrometers. The aim of this work is to understand the effects of the presence of fibers on the drying of this thin-layer product. With this in mind, a specific laboratory set up composed of a near infrared heater is used in order to get the drying kinetics. First, incident heat fluxes received at the product surface and transmittances of materials (semi-transparent medium) are measured with an ad-hoc heat flux sensor. Then, many experiments are performed with and without fibers. For linking the final moisture content to the fibers thermal and hydric behavior, a microscopic analysis of the dried samples is investigated. This analysis is performed for two thicknesses of polymer corresponding to two covering rates of fibers.