Numerical study of bubble nucleation and growth of N2 in low density polyethylene

Abstract

Bubble nucleation and growth were investigated in low density polyethylene (LDPE) using nitrogen (N2). The solubility and diffusivity of N2 in low density polyethylene were determined by a magnetic suspension balance (MSB) system. The bubble nucleation and growth during foaming was assessed using a visualization batch foaming system. It was observed that the increase in temperature and pressure decrement, decreased the bubble density, respectively. The bubble size during the foaming was also studied through numerical model and the effect of various simulation variables on the bubble growth was investigated. It was concluded that the numerical model could predict the foaming process. Moreover, according to the bubble pressure profile, the N2diffusion are formative factors in controlling the bubble growth.