PREDICTION OF CELLULAR STRUCTURE IN FREE EXPANSION POLYMER FOAM PROCESSING

A model is presented for free expansion polymer foam processing that i ncludes simultaneous nucleation and bubble growth. The nucleation mode l includes dissolved gas, small critical cluster size, elastic, and no n-ideal solution effects. An influence volume approach, which couples nucleation and bubble growth, is used to account for the limited suppl y of dissolved gas. The resulting set of equations are solved using a combination of numerical techniques. A parametric study Is conducted t o examine the effects of key process variables on bubble growth, nucle ation, and final bubble size distribution.