Twin-Screw Extruder and Effective Parameters on the HDPE Extrusion Process

Authors: S. A. Razavi Alavi, M. Torabi Angaji, Z. Gholami

Abstract:

In the process of polyethylene extrusion polymer material similar to powder or granule is under compression, melting and transmission operation and on base of special form, extrudate has been produced. Twin-screw extruders are applicable in industries because of their high capacity. The powder mixing with chemical additives and melting with thermal and mechanical energy in three zones (feed, compression and metering zone) and because of gear pump and screw's pressure, converting to final product in latest plate. Extruders with twin-screw and short distance between screws are better than other types because of their high capacity and good thermal and mechanical stress. In this paper, process of polyethylene extrusion and various tapes of extruders are studied. It is necessary to have an exact control on process to producing high quality products with safe operation and optimum energy consumption. The granule size is depending on granulator motor speed. Results show at constant feed rate a decrease in granule size was found whit Increase in motor speed. Relationships between HDPE feed rate and speed of granulator motor, main motor and gear pump are calculated following as: x = HDPE feed flow rate, yM = Main motor speed yM = (-3.6076e-3) x^4+ (0.24597) x^3+ (-5.49003) x^2+ (64.22092) x+61.66786 (1) x = HDPE feed flow rate, yG = Gear pump speed yG = (-2.4996e-3) x^4+ (0.18018) x^3+ (-4.22794) x^2+ (48.45536) x+18.78880 (2) x = HDPE feed flow rate, y = Granulator motor speed 10th Degree Polynomial Fit: y = a+bx+cx^2+dx^3... (3) a = 1.2751, b = 282.4655, c = -165.2098, d = 48.3106, e = -8.18715, f = 0.84997 g = -0.056094, h = 0.002358, i = -6.11816e-5 j = 8.919726e-7, k = -5.59050e-9

Keywords: Extrusion, Extruder, Granule, HDPE, Polymer, Twin-Screw extruder.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1076822

References:

[1] M. Kostis, Polymer Extrusion Simulation and Die Design: Grand Challenge and Opportunity, www.kostic.niu.edu/extrusion, 2002.
[2] Chris Rauwendaal, Polymer Extrusion, Fourth Edition, Hanser Gardner Publisher, 2001.
[3] Prabodh C. Bolur, Extrusion of thermoplastics, technical papers, http://bolur.plastasia.com, 1998.
[4] N. Sombatsompop, M. Panapoy, Comments on temperature profile of PP melt in the barrel of twin screw extruder, polymer testing 20, 2001, pp 217-221.
[5] C. Maier, Polym. Eng. Sci. 36, p 1502, 1996.
[6] I. Sbarski, E. Kosior, S.N. Bhattacharya, Int. Polym. Proc. 12, 1997, p 341.
[7] Holton E. Harris, Extrusion Control, Hanser Gardner Publications. 2004.