First principles cause of melt fracture in LLDPE

Ever since the introduction of LLDPE, the industry has had to deal with problems caused by melt fracture in many processing situations, with the worst problems typically occurring in the production of blown film. Over the years, many mechanisms have been proposed in an attempt to explain the cause and therefore possible cures for melt fracture, but none of these mechanisms has been able to adequately explain the observed phenomena or provide sufficient insight to develop a cure for the problem. Based on experimental observations, a new mechanism based on volatile induced flow defects has been proposed that explains many of the observations that could not previously be explained. This mechanism has allowed us to predict new methods for reducing melt fracture, and tests have proven these predictions to be correct. SEM photos of film samples provide additional evidence in support of this proposed mechanism.