Lifting the Sustainability of Modified Pet-Based Multilayer Packaging Material with Enhanced Mechanical Recycling Potential and Processing

Abstract

Sustainability and recyclability are among the main driving forces in the plastics industry, since the pressure on crude oil resources and the environment is increasing. The aim of this research is to develop a sustainable thermoformable multilayer food packaging, based on co-polyesters, which is suitable for hot-fill applications and allows for recycling in a conventional waste stream. As a polymer material for the outer layer, we selected a modified polyethylene terephthalate (PETM), which is an amorphous co-polyester with a high glass transition temperature (±105 °C) and thus high thermal stability and transparency. The inner layer consists of 1,4-cyclohexylene dimethanol-modified polyethylene terephthalate (PETg), which is allowed to be recycled in a PET stream. Multilayers with a total thickness of 1 mm and a layer thickness distribution of 10/80/10 have been produced. To test the recyclability, sheets which contained 20% and 50% regrind of the initial multilayer in their middle PETg layer have been produced as well. The sheet produced from virgin pellets and the one containing 20% regrind in the middle layer showed no visible haze. This was not the case for the one containing 50% regrind in the middle layer, which was confirmed by haze measurements. The hot-fill test results showed no shrinkage or warpage for the multilayer trays for all temperatures applied, namely 95, 85, 75 and 65 °C. This is a remarkable improvement compared to pure PETg trays, which show a visible deformation after exposure to hot-fill conditions of 95 °C and 85 °C.

Difficulties in performing selective waste collection in the city of Manaus, Brazil

“…The findings of the study by Franz and Silva (2022), for example, point to physical and infrastructural difficulties. Trossaert et al (2022) showed that the lack of infrastructure is crucial for the success of the selective collection, while the study by Santos and Proença (2022) found that the lack of server experience, lack of information system, lack of infrastructure, and lack of technology prevents waste from being collected efficiently. The material causes correspond to the lack of infrastructure and materials and equipment necessary for the practice of reverse logistics; procedural causes concern the procedures of the population to do their part and share information and knowledge so that this practice becomes effective.…”

Silicon‐linked polyethylene glycol‐polyethylene terephthalate (PEG‐PET) nanostructures loaded with Eu3+‐complexes for hybrid luminescent PET materials

“…8 Polyethylene terephthalate (PET) is one of the most popular thermoplastic materials with good processing properties. 9 It is widely used in food and beverage preservation, electronics, medical devices, and other areas, [10][11][12] because of its good transparency, 13 corrosion resistance, 14 high thermal stability, 15 and low production cost. 16 In recent years, PET has also become an important flexible substrate material, 17 for flexible display panels.…”