PET coextrusion

An open-house took place this week at Bandera to display in operation a coextrusion plant for multilayer (A-B-A structure) PET sheet with the inner layer made of 100% recycled PET. The extrudate is destined for in-line thermoforming and converting and the line has been developed for a European converter operating in rigid packaging. The plant output attains, according to sheet width and thickness, 1,200-1,300 kg/h, with peaks of 1,500 kg. The inner layer is made of material from recycling of post-consumer bottles and thermoforming scrap, fed with no pre-treatment thanks to 3 venting units (one of open-air type and two of vacuum type) that allow high level of melt drying and purification to be reached. The extruder for the inner layer is a new-generation corotating twin-screw (L/D = 52). The plant is conceived for enriching the sheet with barrier layers by in-line lamination of PE or PE/EVOH ennobling film at the outlet of the polishing and cooling calender.