An experimental study on shear stress characteristics of polymers in plasticating single-screw extruders

2009 ◽  
Vol 49 (3) ◽  
pp. 471-477 ◽  
Author(s):  
Atakan Altınkaynak ◽  
Mahesh Gupta ◽  
Mark A. Spalding ◽  
Sam L. Crabtree
Keyword(s):  
Experimental Study ◽  
Shear Stress ◽  
Single Screw ◽  
Single Screw Extruders ◽  
Screw Extruders

scholarly journals Melting Behavior of Heterogeneous Polymer Bulk Solids Related to Flood Fed Single Screw Extruders

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2893
Author(s):  
Christian Kneidinger ◽  
Erik Schroecker ◽  
Gernot Zitzenbacher ◽  
Jürgen Miethlinger
Keyword(s):  
Shear Stress ◽  
Polyamide 6 ◽  
Melting Behavior ◽  
Melting Rate ◽  
Polymer Mixtures ◽  
Mixing Ratios ◽  
Single Screw ◽  
Pull Out ◽  
Single Screw Extruders ◽  
Screw Extruders

Melting models for flood fed single screw extruders, like the Tadmor model, describe the melting of pure thermoplastic polymers. However, the melting behavior of heterogenous polymer systems is of great interest for recycling issues, for example. In this work, the melting of polymer mixtures and that of pure bulk polymers by the drag induced melt removal principle is examined both theoretically and experimentally. The applied model experiments represent the melting of the solid bed at the barrel in single screw extruders. As polymer pellet mixtures, polypropylene-homopolymer mixed with polypropylene-block-copolymer, high density polyethylene, polyamide 6, and polymethylmethacrylate were studied using different mixing ratios. The melting rate and the shear stress in the melt film were evaluated dependent on the mixing ratio. The results show that when processing unfavorable material combinations, both shear stress and melting rate can be far below that of pure materials, which was also confirmed by screw extrusion and screw pull-out experiments. Furthermore, approaches predicting the achievable melting rate and the achievable shear stress of polymer mixtures based on the corresponding values of the pure materials are presented.

Melting of PP/PA6 Polymer Blends in Single Screw Extruders – An Experimental Study

2008 ◽  
Vol 587-588 ◽  
pp. 505-509 ◽  
Author(s):  
S.M. Cunha ◽  
António Gaspar-Cunha ◽  
José A. Covas
Keyword(s):  
Experimental Study ◽  
Polymer Blends ◽  
Polymer Blend ◽  
Screw Extruder ◽  
Immiscible Polymer Blend ◽  
Single Screw ◽  
Single Screw Extruder ◽  
Single Screw Extruders ◽  
Melting Mechanism ◽  
Screw Extruders

A prototype modular single screw extruder fitted with a screw extracting device is used to monitor melting of an immiscible polymer blend (PP/PA6, with different weight ratios) in this widely used processing equipment. As anticipated, the phenomena observed are much more complex than those involved in extruding PP or PA6, when the well known Maddock/Tadmor mechanism is valid. Consequently a hybrid melting mechanism, involving Maddock/Tadmor and Dispersive melting sequences, is proposed.

Dependence of solids conveying on screw axial vibration in single screw extruders

2006 ◽  
Vol 102 (3) ◽  
pp. 2998-3007 ◽  
Author(s):  
Qu Jinping ◽  
Shi Baoshan ◽  
Feng Yanhong ◽  
He Hezhi
Keyword(s):  
Axial Vibration ◽  
Single Screw ◽  
Single Screw Extruders ◽  
Screw Extruders
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