Multi-Micro/Nanolayer Films Based on Polyolefins: New Approaches from Eco-Design to Recycling

Abstract

This paper describes a future-oriented approach for the valorization of polyethylene-based multilayer films. The method involves going from eco-design to mechanical recycling of multilayer films via forced assembly coextrusion. The originality of this study consists in limiting the number of constituents, reducing/controlling the thickness of the layers and avoiding the use of tie layers. The ultimate goal is to improve the manufacturing of new products from recycled multilayer materials by simplifying their recyclability. Within this framework, new structures were developed with two polymer systems: polyethylene/polypropylene and polyethylene/polystyrene, with nominal micro- and nanometric thicknesses. Hitherto, the effect of the multi-micro/nanolayer architecture as well as initial morphological and mechanical properties was evaluated. Several recycling processes were investigated, including steps such as: (i) grinding; (ii) monolayer cast film extrusion; or (iii) injection molding with or without an intermediate blending step by twin-screw extrusion. Subsequently, the induced morphological and mechanical properties were investigated depending on the recycling systems and the relationships between the chosen recycling processes or strategies, and structure and property control of the recycled systems was established accordingly. Based on the results obtained, a proof of concept was demonstrated with the eco-design of multi-micro/nanolayer films as a very promising solution for the industrial issues that arise with the valorization of recycled materials.

A Journey from Processing to Recycling of Multilayer Waste Films: A Review of Main Challenges and Prospects

“…More recently, Ref. [57] presented a new approach from eco-designed to recycling of the multilayer structures as an alternative way to improve the valorization process, assuming that their mechanical recycling is possible. This recent work describes a future-oriented approach for the recycling of polyethylene-based multilayer films.…”

“…This study's originality consisted in limiting the number of constituents, reducing/controlling the layer's thickness, and avoiding the use of tie layers as compatibilizers. The ultimate goal was to improve the manufacturing of new products using recycled materials by simplifying their recyclability [57]. Based on the results obtained, a proof of concept was demonstrated with the eco-design approach of multi-micro/nanolayer films as a very promising solution for the industrial issues that arise with the valorization of recycled materials.…”

Status quo and sector readiness for (bio)plastic food and beverage packaging in the 4IR

“…Multi-component injection moulding is gaining in popularity with technical advancements in plastic moulding, with a recent study showing that it may be optimised for processing different recycled polymers in micro-and nano-layers. 65…”

Tensile and thermal behaviour of linear low-density polyethylene nanocomposite films

“…Hence, researchers are tried to improve the properties of a polymer by reinforcing nanofillers [7][8][9]. In particularly the carbonaceous nano fillers are used with thermoset and thermoplastic polymer to achieve good thermal and electrical properties [10][11][12][13]. The nano polymer composites with graphene nanoplatelets (GNPs) have various applications in the electronics sector.…”