PET bottles recycling system for Food applications

PET bottles recycling system for Food applications

Facts and figures: If you’re thinking about a recycling system to go from kerbside PET bottles collection all the way to pellets for food application, here some explanation to make you better understand what it is all about. Flakes for food purposes must have, at least, the following characteristics:   ·        Flow ability:    Free flowing ·        Bulk density     Kg/m3 350-400 ·        Intrinsic Viscosity dl/g           0,75 +/- 0,03 dl/g ·        CIE (b) colour (Gardner method)  - < 1 ·        Fines (< 0,5 mm) % < 0,3 ·        Particle size distribution mm 6-12 mm ·        PH value  -  7 +/- 0,5 ·        Moisture content % < 0,7 ·        Chemical contamination (wash residuals) ppm < 50 ·        Floatable contamination ppm < 60 ·        PVC contamination ppm < 30 ·        Glue contamination ppm < 10 ·        Metal contamination ppm < 20 ·        Other non-melting particles ppm < 45 ·        Green Pet contamination   ppm < 500 ·        Light blue contamination % < 10 ·        Black PET etc.   (e.g. serving trays or material with similar density to PET) ppm < 5 ·        Glass contamination ppm < 5 This as far as washing concern, while the final product to be used into food application should be further pelletized and IV upgraded through a Polycondensation process, in flake form, it can be used right away to spin fibres, to extrude sheets for packaging and for all other "non food" applications. Here will be focusing only the washing process and, at the end of this document, we will be talking a bit about pelletizing and Polycondensation (SSP). It goes by itself that material (PET flakes) should be perfectly clean before going to the last steps of the process and hereafter we will talk extensively about the different steps to achieve perfectly clean flakes; by this we want you to understand why the line has so many machines and the purpose of each one. Let’s start dividing the line into main categories that we define as: Sorting  - Pre-washing - Washing – Drying