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dc.contributor.authorMartyn, Michael T.*
dc.contributor.authorCoates, Philip D.*
dc.date.accessioned2016-10-07T14:35:27Z
dc.date.available2016-10-07T14:35:27Z
dc.date.issued2013
dc.identifier.citationMartyn MT and Coates PD (2013) Pressure Variation during Interfacial Instability in the Coextrusion of Low Density Polyethylene Melts. International Polymer Processing. 28(5): 516-527.
dc.identifier.urihttp://hdl.handle.net/10454/9688
dc.descriptionNo
dc.description.abstractPressure variation during the coextrusion of two low density polyethylene melts was investigated. Melt streams were delivered to a die from two separate extruders to converge in a 30 degrees degrees geometry to form a two layer extrudate. Melt flow in the confluent region and die land to the die exit was observed through side windows of a visualisation cell. Stream velocity ratio was varied by control of extruder screw speeds. Layer thickness ratios producing wave type interfacial instability were quantified for each melt coextruded on itself and for the combined melts. Stream pressures and screw speeds were monitored and analysed. Wave type interfacial instability was present during the processing of the melts at specific, repeatable, stream layer ratios. Increased melt elasticity appeared to promote this type of instability. Analysis of process data indicates little correlation between perturbations in extruder screw speeds and stream pressures. The analysis did however show covariance between the individual stream pressure perturbations. Interestingly there was significant correlation even when interfacial instability was not present. We conclude that naturally occurring variation in extruder screw speeds do not perturb stream pressures and, more importantly, natural perturbations in stream pressures do not promote interfacial instability.
dc.relation.isreferencedbyhttp://dx.doi.org/10.3139/217.2786
dc.subjectMultilayer film coextrusion
dc.subject; Driven channel flow
dc.subject; Viscoelastic fluids
dc.subject; Numerical-simulation
dc.subject; Elastic liquids
dc.subject; Superposed flow
dc.subject; Stability
dc.subject; Die
dc.subject; Stratification
dc.subject; Geometries
dc.titlePressure Variation during Interfacial Instability in the Coextrusion of Low Density Polyethylene Melts
dc.status.refereedYes
dc.typeArticle
dc.type.versionNo full-text in the repository


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