Investigation of the effect of laminated polymers in the metallic packaging materials on the recycling of aluminum by thermal disengagement technology (TDT)

JOURNAL OF CLEANER PRODUCTION

卷:274

Article

Al Mahmood, Abdullah¹  Hossain, Rumana¹  Sahajwalla, Veena¹ 

[1] UNSW Sydney, Ctr Sustainable Mat Res & Technol, Sch Mat Sci & Engn, SMaRT UNSW, Sydney, NSW, Australia

关键词: Laminated metal;    Flexible packaging;    Aluminum;    Oxidation;    Recycling technology;   

DOI  :  10.1016/j.jclepro.2020.122541

来源: Elsevier

【 摘 要 】

Polymer laminated aluminum packaging (PLAP) materials are very useful in high strength flexible packaging applications. Despite the advantages they can offer, there are several difficulties to recycle PLAP into its original metallic form. This study focuses on the effect of different polymeric laminates on the quality of the Al surface recycled by the thermal disengagement technology (TDT). Three different types of flexible PLAP materials have been thermally disengaged in an inert and air atmosphere in 5-30 min at 450 degrees C, 500 degrees C, 550 degrees C, and 600 degrees C. Released gases during the degradation of the polymers have been continuously monitored. After the thermal disengagement of the PLAP material, the surface oxidation was compared with the non-laminated aluminum surfaces that have gone through the same treatment process in the oxygen-enriched atmosphere for 20 min. Complete degradation of the polymers and the dissociation of the volatiles from the PLAP materials was achieved at 550 degrees C within 20 min of the heating process. IR gas analyzer detected hydrogen as the main component from the off gases along with some other greenhouse (CO, CO2) and hydrocarbon (CH4) gases. FTIR, XRD, SEM with EDS mapping, and XPS analysis of the disengaged aluminum (DAl) surfaces demonstrate the rate of oxidation on the non-laminated aluminum is 70-90% higher compared to recycled aluminum from the PLAP materials. A proper selection of TDT parameters minimizes the surface oxidation by the decomposition of the laminated polymers and provides optimum protection against oxidation of the aluminum by the polymers at the initial stage and its degradation components at the final stage by creating a barrier between the Al and surrounding atmosphere. This research shows a pathway to recycle complex packaging materials into less contaminated aluminum without any metal loss. Moreover, highly efficient fuel gas (mainly H-2) and free carbon can also be isolated upon further processing of the off-gases and polymer degraded carbonaceous residue. (c) 2020 Elsevier Ltd. All rights reserved.

【 授权许可】

Free