Multilayer Nanocomposite Polymetric Packaging For Microwave Applications

Microwaveable packaging material should ensure good preservation of the product before cooking/ heating such as high barriers to gases and aromas and adequate control of water vapor transmission. Among the polymers used in flexible packaging, crystalline poly(ethylene terephthalate) (CPET) is characterized by good oxygen barrier properties and quite high heat stability which ensures the absence of alterations of foods flavors. CPET trays or films are suitable for Ready To Cook (RTC) products within a temperature range from -40 to + 220°C. The aim of this work was the production and characterization of nanocomposite multilayer PET films, for microwave applications, in which the nanoclay acts as a heating enhancer. Films prototypes were made by means of laboratory compounding equipment for the production of nanocomposite CPET and by a co-extrusion equipment for producing multilayer films using two different PET copolymer matrices and a modified nanoclay (Cloisite 20A) as heating enhancer. The study of morphology of nanocomposite layer by means of X-ray diffraction experiments was carried out in order to correlate the intercalation/ exfoliation degree of nanoclay with cooking performance.