Trossaert Lynn, De Vel Matthias, Cardon Ludwig, Edeleva Mariya
Centre for Polymer and Material Technologies (CPMT), Department of Materials, Textiles and Chemical Engineering, Ghent University, Technologiepark, 130, Zwijnaarde 9052, 9000 Ghent, Belgium.
Laboratory for Chemical Technology (LCT), Department of Materials, Textiles and Chemical Engineering, Ghent University, Technologiepark, 125, Zwijnaarde 9052, 9000 Ghent, Belgium.
Polymers (Basel). 2022 Jan 4;14(1):196. doi: 10.3390/polym14010196.
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.
由于原油资源和环境面临的压力不断增加，可持续性和可回收性是塑料行业的主要驱动力。本研究的目的是开发一种基于共聚酯的可持续热成型多层食品包装，该包装适用于热灌装应用，并允许在传统废物流中回收利用。作为外层的聚合物材料，我们选择了一种改性聚对苯二甲酸乙二酯（PETM），它是一种非晶态共聚酯，具有高玻璃化转变温度（±105°C），因此具有高的热稳定性和透明度。内层由1,4-环己二醇改性聚对苯二甲酸乙二酯（PETg）组成，它可以在PET流中回收利用。已经生产出总厚度为1毫米、层厚分布为10/80/10的多层材料。为了测试可回收性，还生产了中间PETg层含有20%和50%初始多层材料再研磨料的片材。由原始粒料制成的片材和中间层含有20%再研磨料的片材没有明显的雾度。中间层含有50%再研磨料的片材则不然，雾度测量证实了这一点。热灌装测试结果表明，对于所有应用温度，即95、85、75和65°C，多层托盘均无收缩或翘曲现象。与纯PETg托盘相比，这是一个显著的改进，纯PETg托盘在95°C和85°C的热灌装条件下会出现明显变形。
