A new series of DuPont Entira EP compatibilisers is designed for the recycling of difficult to separate mixtures of polymers. The first Entira EP grades are ethylene-copolymers, optimised for mixed waste streams of polypropylene (PP) and polyethylene (PE) and have now become available in the market. These are said to provide easy-to-process re-granulates with improved low temperature toughness. Specific performance demands can be met by selecting different formulations, used alone or in combination, says DuPont.
Compounding of reground mixed polymers together with Entira EP in an efficiently mixing twin screw extruder or in a single screw extruder with good mixing performance provides re-granulates in pellet form with good mechanical and processing properties, meeting high demands even with high degrees of contamination. The re-compounding process itself is more economical, because using Entira EP is said to reduce the need for melt filter cleaning operations. DuPont says that depending on the selected compatibiliser formulation, the re-compounded materials can reach almost the same level of low temperature toughness as the major blend fraction. Due to their good processing properties, the re-granulates are suitable for injection moulding, extrusion or blow-moulding. Typical applications include their use as blending partner in new materials or as core layer surrounded by new product. Under certain conditions they can even be processed directly.
DuPont is currently developing further formulations of compatibilisers for other mixed materials. These include PE and polyamide (PA) or PE and ethylenvinyl alcohol (EVOH), which are typically used as barrier resins in polyolefin based packaging films, bottles or rigid containers.
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The new series of Entira EP compatibilisers designed for the recycling of difficult to separate mixtures of polymers are optimised for the converting of PP-PE-mixtures, providing easy-to-process re-granulates with improved low temperature toughness. (photo: Dupont)
