Adjustable Internal Deckle Die andTunable Coextrusion Feedblock Technologyfor Extrusion Coating and Laminating

Adjustable Internal Deckle Die andTunable Coextrusion Feedblock Technologyfor Extrusion Coating and Laminating

Sam G. Iuliano
Nordson EDI

Modern internally deckled dies for extrusion coating and laminating processes provide distinct advantages over classic dies with external deckles. Coating width changes can be done efficiently and in a very streamlined manner. Edge trim waste can be minimized by utilizing edge profile control technology to reduce the size of the edge beads. Optional edge encapsulation technology helps to increase line speed when coating low melt strength resins, such as PET.Coextrusion systems need to be designed to resist coextrusion defectsandcompensate for interface distortion to maximize layer uniformity.Having a coextrusion-friendly flow distribution channel in the extrusion die is only part of the solution. An adjustable coextrusion feedblock helps to speed up the process of layer uniformity refinement.The latest design allows the processor to change the positionof thefeedblock’sprofile barsrelative to the combination point. Moving a profile bar closer to the layer combination point amplifies the profiling effect. Conversely, moving a profile bar upstream of the combination point dampens the profiling effect.This allows for many different layer distribution results to be achieved from a single profile cut –all while the extruders remain running.