A maddock mixer design that mitigates gels in polyethylene resin film applications. (April 2023)

• Record Type: Journal Article
• Authors: Spalding, Mark A; Sun, Xiaofei; Kodjie, Stephen L; Du, Libo; Womer, Timothy W; Uzelac, Ned
• Is Part Of: Journal of plastic film and sheeting. Volume 39:Number 2(2023)
• Page Start: 174
• Page End: 189
• Publication Date: 2023-04
• Subjects: Maddock mixer -- UCC mixer -- Leroy mixer -- single-screw extrusion -- screw design -- resin degradation -- polyethylene -- dispersive mixing -- gel mitigation; City planning -- Bibliography -- Periodicals; 668.495
• DOI: 10.1177/87560879221124172
• Languages: English
• ISSNs: 8756-0879

Abstract

Maddock mixers are ubiquitous in plastics processing for single-screw extruders and injection molding plasticators due to their low cost to build and their ability to provide a uniform level of dispersive mixing. If the mixer is designed properly, all entering solid polymer fragments and certain types of gels can be trapped and dispersed into the matrix resin. Many mixers that are used commercially, however, provide lower levels of dispersive stress mixing than required by the process and they can degrade polyethylene (PE) resins. This paper will describe the mechanisms that are occurring in a Maddock mixer and develop guidelines for obtaining optimal mixing stresses while mitigating resin degradation.