Variations of biaxial orientation of polyester film on laminated steel in the laminating process

Polyester film laminated steel for can container will gradually replace lac quer coated steel sheet from environmental consideration and cost reduction . The process is characterized by partial melting of the film on the steel surface during lamination by pressing the supplied films between both sides of heated steel and a couple of cooled rubber rolls. At present, most of polyester films used for the can containers are biaxial ly oriented films and various characteristics of film laminated steel for c an use are strongly influenced by the degree of biaxial orientation of the laminated film. Therefore, this report deals with the result of an experiment regarding var iations of the degree of biaxial orientation with several polyester films, and thermal analysis of these polyester films by means of Differential Scan ning Calorimeter (DSC). Finally, from these experiments, we found that it is possible to estimate t he variation of the degree of biaxial orientation during lamination by mean s of thermal analysis.