METHOD OF TEST AND ASSESSMENT OF RECYCLED POLYMERS FOR FOOD-PACKAGINGUSE UNDER THE ASPECT OF MIGRATION ACROSS A FUNCTIONAL BARRIER

A coextruded three-layered polypropylene (PP) cup with a burried recyc ling PP material (R-PP) layer was investigated with respect to a possi ble food packaging application. From the results of this specific inve stigation a general approach to a test and evaluation procedure for th e reuse of recycled plastic materials in food packagings is presented. The method which focuses on the direct comparison of the R-PP contain ing cup with a food grade PP cup manufactured from virgin material inv olves essentially three levels of investigations: 1. compositional ana lysis of the raw materials, i.e. PP and R-PP granules, 2. compositiona l analysis of the PP and R-PP cup materials and 3. migration testing o f both types of cups applying practical as well as more severe test co nditions. The practical aim of the presented method is to test the PP food contact layer for functional barrier behaviour. One key step to r each this aim is the estimation of migrated amounts under practice-lik e test conditions in concentrations below the analytical detection lim its. This can only be achieved selecting appropriate R-PP specific gui de compounds whose migration are to be monitored under more severe tha n practical conditions.