Multilayer packaging with polyamide can be recycled



ABSTRACT


The multilayer structures are usually used in food packaging as a protective and preservative solution which helps to avoid the food waste. Despite of these kind of structures are often considered non-recyclable, high quality recycled materials can be obtained from multilayer polyamide packages. In fact, this kind of materials have been validated in the main transformation processes as extrusion and injection.


RELEVANCE OF THE MULTILAYER PACKAGING RECYCABILITY


Today, the multilayer flexible packages are a market trend into the food industry due to their good environmental features and competitive price. Their low weight, due to the small quantity of material needed to manufacture these packages, allow an easy transport. However, a key aspect to consider their use in this application is the recyclability after the use. The recycling of multi-material structures, where several plastics can be found, is a challenge, but it is possible either by traditional or by innovative methods (mechanical recycling, chemical recycling, etc).


RECIPAM PROJECT


The study performed in this project has been developed by a consortium formed by UBE (chemical manufacturer), REPOL (engineering plastics compounder), FAPERIN (plastic injection manufacturer), ACTECO (company specialized in waste management and recycling) and AIMPLAS (research and development centre specialized in plastic materials).


RECIPAM aims to study the recyclability of the flexible multilayer structures with polyamide, in both industrial and household waste (in other words: pre and post-consumer). The results reached until now proof the recyclability of this structures, conducted by small changes in the industry which will allow to re-introduce the recycled materials into new goods and products.


In order to reach the expected results, a recycling process and other different transformation processes have been performed, following the steps shown below:



Figure 1: Recycling processes


 


Figure 2: Transformation processes


RECIPAM is a project funded by the Agencia Valenciana de Innovación through to the program “Proyectos Estratégicos en Cooperación”. This program is oriented to support big research and development cooperation projects, where are involved several agents of the Valencian Innovation System, in order to find common solutions for the general interest issues.


RESULTS


1)     Multilayer packages composed by structures as polyamide + polyethylene or polyamide + polypropylene are recyclable.


2)     Good results have been achieved with the following processes: mechanical recycling, mechanical recycling with compatibilisation of mixed materials, separation of layers through physical methods.


3)     Pyrolysis can also be used, to obtain energy or other new recycled materials.


4)     New recycled materials obtained can be used in packaging and automotive applications.


5)     The replacement of recycled materials by virgin material does not imply significant changes in the transformation processes to manufacture the products.


6)     The recycled products obtained have high quality characteristics to be used in the sectors mentioned.


CONCLUSION        


The recyclability of the multilayer packages and the manufacturing of new products from recycled materials allow a decrease of the waste in the landfills, the resource recovery and the reduction of the CO2 emissions