Infrared drying of water based varnish coated on elastomer substrate

• Infrared drying kinetics of an aqueous varnish applied on elastomer substrate are experimentally determined and modeled.
• The conception of a laboratory drying pilot adapted to thin product is described.
• The impact of infrared irradiation on product behavior is study.
• The interest to study crosslinking of varnish by nanoindentation method is put forward.

This study deals with the drying and curing of polyurethane water based varnish by infrared radiation. The varnish is thinly coated on rectangular elastomer substrates. After characterizing their main thermophysical properties, the curing rate is linked to the thermal behavior of varnish. A laboratory setup is developed to retrieve mass and temperature evolutions. First, drying experiments with a constant infrared radiation inferior to 20 kW m−2 are performed. The thermal and hydric behaviors of the product are analyzed in term of drying time and heating rate. Then, several experiments with modulated infrared radiation are carried out. The impact of drying conditions on curing rate of varnish is then discussed.