Polymer Foaming Processes


Details

Common gases used in polymer foams are air, nitrogen, and carbon dioxide. The proportion of gas can range up to 90% or more. The gas is introduced into the polymer by several methods, called foaming processes. These include: The way the gas is distributed throughout the polymer matrix distinguishes two basic foam structures, illustrated in Fig1: A closed cell structure makes a satisfactory life jacket; an open cell structure would become waterlogged. Other attributes that characterize the structure include the relative proportions of polymer and gas and the cell density (number of cells per unit volume) which is inversely related to the size of the individual air cells in the foam.