A numerical and experimental study on weld lines formation and strength in extrusion

Abstract

In this work, we present a study on numerical and experimental approaches aiming to improve our understanding about the relation between the flow conditions and the strength of weld lines in extruded profiles. For this purpose, a prototype extrusion die that comprises a movable spider leg is used to produce tapes under different flow conditions, by varying the location of the spider leg and the flow rate. The same case studies are numerically studied, considering a viscoelastic Giesekus constitutive model. The numerical results are then investigated to identify potential relationships between the flow conditions, in which the weld lines are formed, with the strength of the weld line experimentally characterized. The results obtained allow identifying a clear correlation between the flow conditions and the weld-line strength. POLYM. ENG. SCI., 58:249-260, 2018. (c) 2017 Society of Plastics Engineers