Circular economy assessment in recycling of LLDPE bags according to European Resolution, thermal and structural characterization

According to the Circular Economy Package promoted by the European directive, plastic bags companies must use in their formulations a percentage of polyethylene waste (industrial and/or domestic) greater than 70%. Following that regulation requires an understanding of its consequences in the final p...

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Detalles Bibliográficos
Autores: Ballestar de las Heras, Ricardo Luis, Pradas Bello, Celia, Carrillo Navarrete, Fernando|||0000-0002-7357-9143, Cañavate Ávila, Francisco Javier|||0000-0002-1502-6962, Colom Fajula, Xavier|||0000-0003-3511-852X
Tipo de recurso: artículo
Fecha de publicación:2022
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/367306
Acceso en línea:https://hdl.handle.net/2117/367306
https://dx.doi.org/10.3390/polym14040754
Access Level:acceso abierto
Palabra clave:Sustainable engineering
Recycling (Waste, etc.)
Mechanical recycling
Polyethylene degradation
Circular economy
Recycled LLDPE
Thermal analysis
Economia circular
Reciclatge (Residus, etc.)
Àrees temàtiques de la UPC::Enginyeria química
Descripción
Sumario:According to the Circular Economy Package promoted by the European directive, plastic bags companies must use in their formulations a percentage of polyethylene waste (industrial and/or domestic) greater than 70%. Following that regulation requires an understanding of its consequences in the final product from an industrial point of view. This manuscript analyzes the thermal and morphological changes related to the tear resistance of linear-low density polyethylene (LLDPE) samples from industrial waste generated by the company Sphere Spain subjected to the degradation produced by the recycling cycles. The process is analogue to the industrial, starts from samples in pellets then a film by blow extrusion is obtained (odd steps) and posteriorly this film is recycled to pellets again (even steps). The results obtained show that the LLDPE samples develop two crystalline structures (CS1 and CS2) which evolve differently through the recycling cycles with a tendency to decrease in crystallinity due to degradation that is not the same for the process of obtaining film or recycling to pellet. The molecules with a more linear structure and a longer chain break and branch. The more branched structure increases and tends to crosslinking. This leads to a decrease in tear strength in the longitudinal direction, which is not so evident in the transversal direction. The samples could admit four recycling cycles with and acceptable tear resistance. The longitudinal tear strength value decreases by 40% for each film and 20% in the case of tearing in the transverse direction. The results obtained in this research work show that the regulations included in the cited circular economy package can be applied in the manufacture of consumer bags, helping also to reduce the dependence of manufacturers on fluctuations in delivery by collapses in shippin