A study of foaming mechanisms in rotational molding

The presented research focuses on the fundamentals of the foaming process in rotational molding and control of final cellular structure. The experimental results of foaming experiments, performed under isothermal and non-isothermal conditions, indicate that the foaming process could be divided into three distinct phases: bubble nucleation, bubble growth and bubble coalescence. It was found that bubble growth and coalescence mechanisms are dynamically competing during the entire foaming process and the degree of uniformity and structure of the final foam are primarily determined by the nucleation stage.