An experimental study of single-screw extrusion of HDPE–wood composites

✍ Scribed by Karen Xiao; Costas Tzoganakis

• Book ID: 102691716
• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 800 KB
• Volume: 29
• Category: Article
• ISSN: 0730-6679
• DOI: 10.1002/adv.20190

✦ Synopsis

Abstract

Single‐screw extrusion experiments were carried out to study the extrusion characteristics of HDPE–wood composites. Three screw geometries (A, B, and C) were used, and the effects of screw speed on output, melting, and pressure profile were studied. Screw A had a much higher compression ratio than screws B and C, which directly affected the melting behavior of the polymers. Screws B and C had the same compression ratio; however, screw C had the same metering capacity as screw A. Therefore, by comparing screws B and C, the effect of feed depth on the solid conveying capacity was investigated. It was found that while screw B had higher outputs than both screws A and C as expected, screw C had a much lower output than screw A for highly filled resins even though they had the same metering capacity. For HDPE, screws A and C showed the same output as expected. Further examinations of the pressure profiles and melting profiles from screw extraction experiments confirmed that screw C showed a severely starved solids conveying capacity for wood‐filled resins, which limited the total outputs. Comparing the outputs and pressure generations between theoretical predictions and actual experimental results, it was evident that due to the inaccurate assumption of fully filled channels common in single screw extrusion, both outputs and pressure generations in the extruders were overpredicted. © 2010 Wiley Periodicals, Inc. Adv Polym Techn 29:197–218, 2010; View this article online at wileyonlinelibrary. DOI 10.1002/adv.20190