Aluminium scrap often contains lacquer and paint. This coat can be removed prior to melting by heating the scrap. The degradation of polyester coating on aluminium sheets was studied in air, O2, N 2, Ar, and Ar with 1% O2 using thermogravimetry/differential thermal analysis. The samples were heated up to 620 degree C (heating rates 0.5-50 degree C/min). Data are presented that can be used to develop a phenomenological model of pyrolysis and combustion of the coating. Also a simple kinetic model estimating the activation energy and constant-temperature degradation time is presented. In general the experimental methods obtained here can be used to describe decoating of scrap. From the models suitable atmosphere, temperature and residence time in industrial delacquering units can be chosen.

TECHNICAL PARAMETER