Influence of flow pattern development at die entrance and inside annular die on extrudate swell behavior of NR compound

• Main Authors: Naret Intawong, Sittichai Udomsom, Konnatee Sugtakchan, Watcharin Sitticharoen
• Format: Article
• Language: English
• Published: Associação Brasileira de Polímeros 2015-10-01
• Series: Polímeros
• Subjects: capillary rheometer; annular die; diameter swell ratio; thickness swell ratio; NR compound
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-14282015000500013&lng=en&tlng=en

Abstract This research studies influence of the flow pattern at annular die entrance through the inside of annular die flow channel of capillary rheometer on the swell behavior of NR compound. The annular die used in this research was specifically designed to create the specific pattern of Vortex Flow at Die Entrance (VFE) of NR compound. Results of the study showed that the thickness swell ratio was higher than diameter swell ratio by an average of 20% at every die gap size. It was also found that the VFE flow pattern had direct significant influence on the swell behavior of NR compound while extrudating through annular die. Results from the study of the flow pattern could be used to explain why the thickness swell ratio is higher than the diameter swell ratio in every test condition.