Experimental and numerical studies on the effects of pressure release rate on number density of bubbles and bubble growth in a polymeric foaming process

Influence of thermobaric conditions on size distribution of colloidal gas aphrons

“…The nucleation is governed by the gas supersaturation which is a time-dependent quantity as the pressure is usually released at a finite rate. The dependence of the BSD on pressure release rate has been studied in a number of experimental works [8,9], however there is still no analytical description of the effect [11]. The other stages are governed by diffusion and provide scarce opportunities for the BSD control.…”

Numerical simulation of polymer foaming process in extrusion flow

“…Typically polymer foaming processes involve the diffusion-induced growth of gas bubbles in polymeric liquids under either an injection moulding or extrusion process (Tuladhar and Mackley, 2004). Extrusion processes usually consists of four stages: (1) the dissolution of foaming agent into a polymer melt at elevated pressure; (2) the nucleation of bubbles in a supersaturated solution of foaming agent in a molten polymer; (3) the growth of bubbles in a molten polymer and (4) the stabilization of the cellular structure by lowering the temperature below the melting point or the glass transition temperature of polymer (Taki, 2008).…”

Foaming morphology control of microcellular injection molded parts with gas counter pressure and dynamic mold temperature control

“…Taki [4] studied the effects of pressure release rate on bubble density and sizes. This study applies the welldeveloped models of cell foaming to couple with 3D flow motion technology for microcellular injection molding.…”

“…The details of several model developments can be found in the papers by Taki [4]. We consider the single phase fluid is of binary constitution, SCFs dissolved in polymer melt, before onset of bubble nucleation.…”