Polymer Melt Flow through Capillary with An Additional Vibration Component*

Yue Jun Liu¹,** Jin Ping Qu²

^1. Key Laboratory of New Material and Technology for Package,

Zhuzhou Institute of Technology, Zhuzhou, 412008, China

^2. The National Engineering Research Center of Novel Equipment for Polymer Processing, South China University of Technology, Guangzhou 510640, China

Abstract:

The dynamic shear flow of a polymer melt in a capillary was analyzed deeply based on a novel rheological measuring apparatus which has an additional sinusoidal vibration component, then the rheological model of polymer melt under the action of vibration was set up. Through measuring and analyzing the instantaneous rheological data of a LDPE melt, including the capillary entry pressure, the volume flow rate and their phase-difference under a preset frequency and amplitude of vibration, the capillary pressure drop and the apparent viscosity of LDPE melt within a capillary were obtained. It was discovered that the capillary pressure drop and the apparent viscosity of LDPE melt under various amplitudes and frequencies of vibration emerge a tendency of nonlinear change; compared with the stable state extrusion, the capillary pressure drop and the apparent viscosity of LDPE melt decrease after introducing a sinusoidal vibration.

Keywords: LDPE melt; Vibration; Pressure drop; Apparent viscosity

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* Supported by the National Nature Science Foundation of China (No. 29904001) and the Hunan Provincial Nature Science Foundation of China (No. 04JJ40015)

** Author to whom correspondence should be sent:

Key Laboratory of New Material and Technology for Package,

Zhuzhou Institute of Technology, Zhuzhou, 412008, China

E-mail: liu_yue_jun@tom.com; Fax: 86-(0)733-2622252