The term “gel” refers to any small defect that distorts a film product. Eliminating gel defects from extruded polyethylene film products can be difficult, time consuming, and expensive due to the problem's complexity and the off-specification product produced. This paper discusses how to: identify gel types, common root causes, and technical solutions for mitigating gels in film products produced using single-screw extruders.
SunXGouQSpaldingMAet al.Optimization of maddock-style mixers for single-screw extrusion. SPE-ANTEC Tech Papers2016; 62: 898.
13.
SunXSpaldingMAWomerTWet al.Optimization of maddock-style mixers for single-screw extrusion. SPE-ANTEC Tech Papers2017, pp. 63.
14.
HyunKSSpaldingMA. Troubleshooting TPU resin extrusion rate limitations due to solids in the discharge. SPE-ANTEC Tech Papers2012, pp. 58.
15.
MaddockBH. A visual analysis of flow and mixing in extruder screws. SPE J1959; 15: 383.
16.
SpaldingMADooleyJHyunKS. The effect of flight radii size on the performance of single-screw extruders. SPE-ANTEC Tech Papers1999; 45: 190.
17.
MoffatHK. Viscous and resistive eddies near a sharp corner. J Fluid Mech1964; 18: 1.
18.
NajarzadehZAbdellah AjjiA. Role of molecular architecture in interfacial self-adhesion of polyethylene films. J Plastic Film Sheeting2017; 33: 1.
19.
SpaldingMAWomerTW. Mitigating gels in polyethylene products produced using grooved-bore, single-screw extruders. SPE-ANTEC Tech Papers2017, pp. 63.
20.
Recommended Dimensional Guideline for Single Screws. The Society of the Plastics Industry, Inc.
21.
Maillefer C. Patent, 363,149 Swiss, 1962.
22.
Gale GM. Extruder mixer. Patent 4,419,014, USA, 1983.
23.
WangCManus-ZloczowerI. Flow field analysis of a cavity transfer mixer. Polym Eng Sci1994; 34: 1224.
24.
NeubrechBKarrenbergGWortbergJ. Virtual and experimental comparison of different dynamic mixing devices for single-screw extrusion. SPE-ANTEC Tech Papers2017, pp. 63.
25.
SpaldingMAPowersJ. Elimination of defects from injection molded parts via screw modifications. SPE-ANTEC Tech Papers2009; 55: 2463.
26.
SpaldingMACampbellGA. Using hypothesis setting to optimize the troubleshooting process for single-screw plasticators. SPE-ANTEC Tech Papers2011; 57: 1392.
