|Kinematic Modeling of Melting Processes in Plasticating
Mitsubishi Chemical Group Science and Technology Research Center, Inc., Mie, Japan
Nippon Gomu Kyokaishi, (2004), 77(4), 124-129 General Review in Japanese.
Since the melting theory in a single screw extruder was established by Tadmor in 1966, a large number of kinematic models has been proposed based on his model. According to his theory, the melting takes place at the interface between the hot barrel and the unmolten polymer called the solid bed. The heat conducted from the barrel and generated by viscous dissipation at the interface reduces the width of the solid bed along the screw down channel.
On the other hand, the melting theory in a twin screw extruder was recently proposed by Potente in the mid-90s and it is still developing. According to several observations, the melting processes are classified into the Tadmor type and the suspension type. The latter type of melting is that the solid particles which are dispersed in the melt reduce their size by heat conduction from the melt. Besides these models, Gogos referred to the importance of the energy dissipation caused by plastic deformations of solid materials in the kneading block region.
In this article, the author reviews the melting models of both the single and the twin screw extruders, focusing on the recent development in this field.
Melting, Plastic, Extruder, Tadmor model, Suspension model