Recycling

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17 pages, 3206 KiB

Open AccessArticle

Improvement of Thermal Protection in Recycled Polyolefins through Hybrid Mesoporous Silica–Antioxidant Particles

by Enrique Blázquez-Blázquez, Rosa Barranco-García, Tamara M. Díez-Rodríguez, Pilar Posadas, Ernesto Pérez and María L. Cerrada

Recycling 2024, 9(1), 3; https://doi.org/10.3390/recycling9010003 - 2 Jan 2024

Cited by 1 | Viewed by 2854

Abstract

The deficient management of plastic waste has caused a serious worldwide environmental problem. Thus, one of the main challenges for the industry in the plastics sector in contributing to sustainability and a circular economy consists of providing a subsequent service life to this [...] Read more.

The deficient management of plastic waste has caused a serious worldwide environmental problem. Thus, one of the main challenges for the industry in the plastics sector in contributing to sustainability and a circular economy consists of providing a subsequent service life to this waste. For that purpose, the appropriate incorporation of antioxidants will play a key role in preventing or postponing the degradation of plastic waste, where the formation of radicals is initiated during its previous lifetime by the action of degrading agents. Functionalized particles, based on mesoporous MCM-41 silica with Irganox 1076, were prepared with two different protocols and were further incorporated into a material containing virgin PP and 30 wt.% of recycled PP, with the purpose of guaranteeing thermal stability during its next service life. A very significant increase in the thermal stability of the resulting composites was found, attributable to the synergistic action between the Irganox 1076 antioxidant and the MCM-41 particles. In addition, the presence of hybrid particles leads to an important nucleating effect for the crystallization of PP. Moreover, a reinforcing role was also played by these modified mesoporous silicas in the resultant systems. The presented methodology constitutes, therefore, a promising strategy for contributing to the circular economy—since the synergy between the Irganox 1076 antioxidant and MCM-41 particles was found to play an important role in the ultimate performance of recycled polyolefins. Full article

(This article belongs to the Special Issue Advances in the Recycling, Processing and Use of Plastic Waste II)

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16 pages, 3499 KiB

Open AccessArticle

Quantification of Plastics in Agriculture and Fisheries at a Regional Scale: A Case Study of South West England

by Maria Eugenia Correa-Cano, Kerry Burton, Markus Mueller, Victor Kouloumpis and Xiaoyu Yan

Recycling 2023, 8(6), 99; https://doi.org/10.3390/recycling8060099 - 14 Dec 2023

Cited by 1 | Viewed by 2729

Abstract

The use of plastics in agriculture and in fisheries has been vital to increase food production and meet the demands of an increasingly growing global population. However, there are several drawbacks to the use of plastics in these industries. Most plastics used in [...] Read more.

The use of plastics in agriculture and in fisheries has been vital to increase food production and meet the demands of an increasingly growing global population. However, there are several drawbacks to the use of plastics in these industries. Most plastics used in agriculture are disposed of after one single use and are highly susceptible to weathering. Abandoned, lost, or discarded fishing gear cause considerable damage to marine life. Quantification of plastic waste generation in these industries is scarce or non-existent in the case of fisheries. In this paper, we estimate the amount of plastic waste generated by agriculture and fisheries at a regional scale, considering the South West of the UK as a case study. We followed a mass balance approach to quantify the potential plastic waste generated by these industries. We find a generation of 49 kt of plastic waste in agriculture, 47% of which has an unknown fate. We estimate 454 t/year of fishing gear waste, with unclear end-of-life pathways. A detailed quantitative understanding of plastic waste generation per sector at a regional scale is fundamental for tracking plastic waste flows, locating hotspots of pollution, and planning actions to reduce the amount of plastic waste along the chain of end-users. Full article

(This article belongs to the Special Issue Advances in the Recycling, Processing and Use of Plastic Waste II)

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16 pages, 5398 KiB

Open AccessArticle

Exploring the Plastic Collection and Recycling Trends in Sri Lanka

by Rohantha Rukshan Jayasinghe, Wasudha Prabodhani Abeyrathna, Krishani Rukmali Jayasingha, Manuja Promodya Hendawitharana, Thusitha Saman Bandara, Champika L. Liyanage and Karl S. Williams

Recycling 2023, 8(6), 94; https://doi.org/10.3390/recycling8060094 - 26 Nov 2023

Viewed by 6853

Abstract

This study examined plastic waste management in Sri Lanka, concentrating on the contributing factors to plastic waste generation and collection. Data were gathered through a questionnaire survey from registered plastic recycling and management centres. The analysis revealed a positive correlation between tourist arrivals [...] Read more.

This study examined plastic waste management in Sri Lanka, concentrating on the contributing factors to plastic waste generation and collection. Data were gathered through a questionnaire survey from registered plastic recycling and management centres. The analysis revealed a positive correlation between tourist arrivals and plastic waste generation, indicating increased plastic waste production due to tourism spanning from 2014 to 2022. However, plastic waste collection negatively correlated with precipitation levels, suggesting heavy rainfall hampers collection efforts. This study found HDPE, PVC, LDPE, and PP to be the most collected and recycled plastic types, whereas PS and PET recycling were less prevalent. The results demonstrate the need for enhanced recycling infrastructure and highlight the necessity for government participation in plastic waste management initiatives. This study recommends increasing waste collection and recycling during the tourist season. In addition to enhancing public and private awareness, there should be additional investment in recycling facilities. The findings offer crucial insights into plastic waste management in Sri Lanka, emphasizing the importance of collaborative efforts and comprehensive strategies to tackle plastic pollution. Full article

(This article belongs to the Special Issue Advances in the Recycling, Processing and Use of Plastic Waste II)

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23 pages, 2100 KiB

Open AccessArticle

Safety Assessment of Recycled Plastics from Post-Consumer Waste with a Combination of a Miniaturized Ames Test and Chromatographic Analysis

by Elisa Mayrhofer, Lukas Prielinger, Victor Sharp, Bernhard Rainer, Christian Kirchnawy, Christian Rung, Anita Gruner, Mladen Juric and Arielle Springer

Recycling 2023, 8(6), 87; https://doi.org/10.3390/recycling8060087 - 4 Nov 2023

Cited by 6 | Viewed by 5684

Abstract

European circular economy goals require the use of recycled polymers in sensitive applications such as food packaging. As plastic recyclates can contain unknown post-consumer substances, the European Food Safety Authority evaluates recycling processes using a worst-case assumption: all contaminants are DNA-reactive mutagens/carcinogens with [...] Read more.

European circular economy goals require the use of recycled polymers in sensitive applications such as food packaging. As plastic recyclates can contain unknown post-consumer substances, the European Food Safety Authority evaluates recycling processes using a worst-case assumption: all contaminants are DNA-reactive mutagens/carcinogens with extremely low safety thresholds. The current data are insufficient to estimate whether this assumption is justified. To provide scientific evidence on the presence of DNA-reactive mutagens in recycled plastics, 119 input and output samples from plastic recycling were tested with a miniaturized Ames test. DNA-reactive mutagens were not detected in recycled polyethylene terephthalate, which is already approved for food contact. However, other types of recycled plastics (polyethylene, polypropylene and polystyrene), which are currently unauthorized for food contact, showed DNA-reactive, mutagenic effects in a total of 51 samples. The DNA-reactive substances that are responsible for the detected mutagenic activity could not be identified by comparison of the bioassay data with analytical results from a chromatographical screening. The data from the Ames test analysis of different independent batches and a comparison of input and output material indicate that the DNA-reactive contaminants are not randomly introduced through the misuse of recycled packaging by consumers, but are systematically formed during the recycling process from precursors in the input. This publication highlights the need to identify the source for this critical contaminant to enable the future use of polyethylene, polypropylene and polystyrene in sensitive applications. Full article

(This article belongs to the Special Issue Advances in the Recycling, Processing and Use of Plastic Waste II)

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19 pages, 6423 KiB

Open AccessArticle

An Experimental Approach to Determining the Average Diffusion Coefficient of Volatile Components in Polymer Waste Materials

by Chi Nghia Chung, Christian Marschik, Jakub Klimosek, Juraj Kosek, Mohamad Hassan Akhras and Georg Steinbichler

Recycling 2023, 8(5), 72; https://doi.org/10.3390/recycling8050072 - 21 Sep 2023

Cited by 2 | Viewed by 2338

Abstract

One of the major challenges in recycling plastics is the removal of undesired volatile components from the polymeric phase, which may reduce process efficiency and negatively affect product quality. Accordingly, the recycling industry employs a broad range of degassing techniques, the efficiency of [...] Read more.

One of the major challenges in recycling plastics is the removal of undesired volatile components from the polymeric phase, which may reduce process efficiency and negatively affect product quality. Accordingly, the recycling industry employs a broad range of degassing techniques, the efficiency of which often depends on the diffusion coefficient—a measure of the mass transport of volatile components in polymeric phases. The aim of this study was to develop a practically feasible experimental approach using thermogravimetric analysis (TGA) to determine the average diffusion coefficient of volatile components in polymer waste materials. First, the TGA method was validated with a pressure decay apparatus (PDA) using predefined binary material mixtures: Thin sheets were pressed from virgin high-density polyethylene (HDPE) and polypropylene (PP) and deliberately saturated with toluene in a sorption experiment. These saturated samples were then used in TGA and PDA desorption experiments at 60 °C, 80 °C and 100 °C, which yielded similar results with an average difference of 7.4% for the HDPE-toluene system and 14.7% for the PP-toluene system. When validated, TGA was employed to determine the diffusion coefficient of volatile components in post-industrial plastic waste melt at a temperature of 220 °C. The proposed method contributes to the understanding of diffusion-based mass transport in polymer waste materials and provides a key parameter for model-based process control and optimization. In practice, the diffusion coefficient results can be used to predict the degassing performance of an extrusion process in the mechanical recycling of plastic waste. Full article

(This article belongs to the Special Issue Advances in the Recycling, Processing and Use of Plastic Waste II)

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15 pages, 1083 KiB

Open AccessArticle

The Challenge of Plastic Management for Waste Electrical and Electric Equipment Recycling in the Global South: A Case Comparison between Europe and Latin America

by Cecilia Chaine, Andrew S. Hursthouse, Iain McLellan, Evi Viza and Jan Miller

Recycling 2023, 8(5), 71; https://doi.org/10.3390/recycling8050071 - 15 Sep 2023

Cited by 1 | Viewed by 2621

Abstract

Countries with emerging legislation on the waste electrical and electric equipment (WEEE), but limited infrastructure, may find in other, more robust, systems the tools to develop adaptable and socioeconomically viable management schemes. Additives found in the plastics in electronic goods, such as brominated [...] Read more.

Countries with emerging legislation on the waste electrical and electric equipment (WEEE), but limited infrastructure, may find in other, more robust, systems the tools to develop adaptable and socioeconomically viable management schemes. Additives found in the plastics in electronic goods, such as brominated flame retardants (BFRs), are components of a safety system, but introduce characteristics that result in their waste being hazardous. Established and emerging regulatory systems need to implement legislation that impacts the management of WEEE, to reduce risks to human health and the environment, while maximising opportunities for resource recovery from widely varying materials. To assess the context of developed and emerging regulatory systems, a baseline study was undertaken of WEEE plastics in Scotland and Uruguay. For the identification of BFRs in plastics, an internationally validated screening methodology using X-ray fluorescence was adopted at different processing operations. It was observed that, using a threshold of 830 mg/kg for Br as a BFR tracer, in Scotland, more than 70% of the plastics would be recyclable, while, in Uruguay, that fraction dropped to 50%. These results, and the wider literature discussion, highlight the impact that regulatory frameworks have on the quality and recyclability of recovered material. We identify future actions to be considered by policy-makers for a more sustainable regulatory approach. Full article

(This article belongs to the Special Issue Advances in the Recycling, Processing and Use of Plastic Waste II)

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16 pages, 3757 KiB

Open AccessArticle

Valuation of Plastic Waste as a Community Circular Economy Strategy in the Municipality of Choco–Colombia

by Angie Tatiana Ortega-Ramírez, Miriam Reyes Tovar, Nelly del Carmen Elmira Castro and Oscar Silva-Marrufo

Recycling 2023, 8(3), 52; https://doi.org/10.3390/recycling8030052 - 20 Jun 2023

Cited by 2 | Viewed by 2572

Abstract

A business solution is proposed for the accumulation of waste in the Municipality of Choco without prior treatment through the establishment of a center for the reception, classification, recovery and use of solid plastic waste in the Municipality of Quibdo, which would optimize [...] Read more.

A business solution is proposed for the accumulation of waste in the Municipality of Choco without prior treatment through the establishment of a center for the reception, classification, recovery and use of solid plastic waste in the Municipality of Quibdo, which would optimize and expand the management of plastic waste. In this study, the basic diagnosis of the practices that are currently carried out in Quibdo is evaluated with the appropriation of the knowledge of the population, the technical structuring of the conditions of production of plastic wood is carried out from the management of plastic waste, recognition of the market for waste generated as an alternative for development and sustainable growth and the financial feasibility of the project and the profitability of each of the investment plans for its implementation. The results of the investigation include the identification of weaknesses and opportunities in waste management practices and the proposal of two investment plans for the establishment of the center. It is concluded that investment plan 2 would require 46,590.50 USD less than investment plan 1, equivalent to a 2.21% return compared to investment plan 1. Full article

(This article belongs to the Special Issue Advances in the Recycling, Processing and Use of Plastic Waste II)

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20 pages, 2244 KiB

Open AccessArticle

Effect of Virgin PP Substitution with Recycled Plastic Caps in the Manufacture of a Product for the Telephony Sector

by Beatriz Arioli de Sá Teles, Isadora Luiza Clímaco Cunha, Manoel Lisboa da Silva Neto, Hélio Wiebeck, Ticiane Sanches Valera, Simara Silveira de Souza, Alfredo Felipe de Oliveira Schmitt, Vinicius Oliveira and Luiz Kulay

Recycling 2023, 8(3), 51; https://doi.org/10.3390/recycling8030051 - 9 Jun 2023

Viewed by 3310

Abstract

This study investigated the effects of partial and total substitutions of fossil polypropylene (PP) for recycled plastic cap equivalents in the manufacture of signage labels used by the telephone industry. Four alternative scenarios to using virgin PP were evaluated considering recycled material in [...] Read more.

This study investigated the effects of partial and total substitutions of fossil polypropylene (PP) for recycled plastic cap equivalents in the manufacture of signage labels used by the telephone industry. Four alternative scenarios to using virgin PP were evaluated considering recycled material in flake and pellet forms based on environmental performance, degree of circularity, and technical behavior. The environmental analysis was performed by the life cycle assessment (LCA) technique, and for all impact categories evaluated, using recycled material to replace the virgin reduced adverse effects on the environment. The most significant results in this dimension, with gains of 81% in the Global Environmental Indicator, occurred when recycled PP flakes entirely replaced the fossil polymer. Once again, the highest values of the Materials Circularity Indicator (MCI) were achieved by scenarios with full recycled resin in processing the tags; however, this product must also be reused. The mechanical behavior of the tags measured technical performance, and in this case, the product made with virgin PP outperformed the recycled options except for elongation. An analysis that integrated the three dimensions into a single performance index pointed to the complete substitution of virgin material for recycled as the most balanced option. Full article

(This article belongs to the Special Issue Advances in the Recycling, Processing and Use of Plastic Waste II)

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24 pages, 7305 KiB

Open AccessArticle

Microfactory Design for Valorization of E-Waste Plastics (Acrylonitrile-Butadiene-Styrene, Polycarbonate, and Polypropylene) on Additive Manufacturing Sector

by Alejandro Moure Abelenda and Farid Aiouache

Recycling 2023, 8(3), 46; https://doi.org/10.3390/recycling8030046 - 1 May 2023

Cited by 2 | Viewed by 3700

Abstract

Less than half of e-waste plastics are sorted worldwide, and this rate is likely to decline as major processing countries have banned importation of e-waste plastics. This forces the development of decentralized processing facilities, also known as microfactories. The present work investigates the [...] Read more.

Less than half of e-waste plastics are sorted worldwide, and this rate is likely to decline as major processing countries have banned importation of e-waste plastics. This forces the development of decentralized processing facilities, also known as microfactories. The present work investigates the recyclability of different grades of acrylonitrile-butadiene-styrene (ABS) copolymer, polycarbonate, and polypropylene, which were found to be very abundant in a recycling site in the UK. The determination of the matrix relied on the resin identification codes imprinted in the e-waste plastics and subsequent Fourier-transform infrared spectroscopy (FTIR). Melt-blend extrusion technology enabled the valorization of the wasted thermoplastics as 3D filament without significant degradation of the polymers. The recycled materials maintained the tensile strength at around 2.5 MPa in agreement with the specifications offered by virgin polymers. Further characterization was done by means of laser microscope, thermogravimetric analysis, and X-ray fluorescence to determine the commercial viability of the recycled filament. A modified solvent-based method was developed with acetone to remove the brominated flame retardants: 25 g/100 mL, 30 min of contact time, and 4 extraction steps. The FTIR results show that the degradation of the rubbery dispersed phase corresponding to the butadiene can be accumulated in the less soluble fraction of the extracted ABS. Full article

(This article belongs to the Special Issue Advances in the Recycling, Processing and Use of Plastic Waste II)

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20 pages, 2416 KiB

Open AccessArticle

Controlled Combustion and Pyrolysis of Waste Plastics: A Comparison Based on Human Health Risk Assessment

by Arianna Moranda and Ombretta Paladino

Recycling 2023, 8(2), 38; https://doi.org/10.3390/recycling8020038 - 3 Apr 2023

Cited by 1 | Viewed by 4230

Abstract

Increasing conditions of economic and social well-being have led to an increase in waste production. Among the waste products, a significant portion consists of plastic materials that are popular in the components of consumer goods. For this reason, the conversion of plastic to [...] Read more.

Increasing conditions of economic and social well-being have led to an increase in waste production. Among the waste products, a significant portion consists of plastic materials that are popular in the components of consumer goods. For this reason, the conversion of plastic to energy via controlled combustion and plastic to fuel via thermal/catalytic pyrolysis or gasification can be proposed to treat the residual heterogeneous mixed plastics that cannot be recovered as individual polymers. The quality and type of fuels that are possible to obtain from these processes are different, as is the quality of their emissions, which generally contain VOCs, PCBs, dioxins, PAHs, and heavy metals. In this work, we propose a methodology based on human health risk assessment to compare controlled combustion and catalytic pyrolysis. Many pathways are analyzed, and pollutant concentrations are computed in the atmosphere, water, vegetables, fish, and food. Exposure is evaluated for inhalation and ingestion routes by taking into account uncertainties. Our results show that the risk profile of catalytic pyrolysis is low. Controlled combustion remains an interesting process, but even if Best Available Technologies (BAT) are adopted, the cancer risk due to PAHs contained in particulate is around the threshold for people living near the plant if a long period of operation is considered. Full article

(This article belongs to the Special Issue Advances in the Recycling, Processing and Use of Plastic Waste II)

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15 pages, 1493 KiB

Open AccessArticle

Strategies for Sustainable Management of Agricultural Waste Vinyl in South Korea

by Dowan Kim, Eunsook Kim and Chaegun Phae

Recycling 2023, 8(2), 33; https://doi.org/10.3390/recycling8020033 - 3 Mar 2023

Viewed by 5504

Abstract

Vinyl, such as those in the form of mulching and vinyl houses, is used to improve agricultural productivity. It is generated as an agriculture waste vinyl (AWV) after use. The collected AWV is transported to a recycling facility and shredded, washed, and compressed [...] Read more.

Vinyl, such as those in the form of mulching and vinyl houses, is used to improve agricultural productivity. It is generated as an agriculture waste vinyl (AWV) after use. The collected AWV is transported to a recycling facility and shredded, washed, and compressed to be recycled. Recycled materials can contribute to the circular economy of agriculture as they are used again as an agricultural plastic product. However, in Korea, there are concerns about the illegal disposal (landfill, incineration) of AWV. So, a new management model is needed in which stakeholders voluntarily establish an AWV management system. In this study, a sustainable management strategy was proposed. This strategy is reinforcing the responsibility of the producers of AWV and forms a value chain in the proper discharge after consumption by applying the deposit system proposed to recover AWV. Local governments and the National Agricultural Cooperative Federation (NH) proposed education to curb the illegal disposal of AWV, and for managing areas where a collection system has not yet been established, biodegradable mulching vinyl (BMV) was proposed to minimize the environmental pollution caused by AWV. It was calculated that the EPR contribution was 0.16 USD/kg, and the introduction of BMV was 0.42 USD/kg in Korea. This study will provide a new alternative in countries struggling with AWV management. Full article

(This article belongs to the Special Issue Advances in the Recycling, Processing and Use of Plastic Waste II)

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13 pages, 9604 KiB

Open AccessArticle

Comparison between the Mechanical Recycling Behaviour of Amorphous and Semicrystalline Polymers: A Case Study

by André A. Costa, Pedro G. Martinho and Fátima M. Barreiros

Recycling 2023, 8(1), 12; https://doi.org/10.3390/recycling8010012 - 10 Jan 2023

Cited by 7 | Viewed by 3648

Abstract

The increase in waste has motivated the adoption of the circular economy concept, which assumes particular relevance in the case of plastic materials. This has led to research of new possibilities for recycling plastics after their end-of-life. To achieve this goal, it is [...] Read more.

The increase in waste has motivated the adoption of the circular economy concept, which assumes particular relevance in the case of plastic materials. This has led to research of new possibilities for recycling plastics after their end-of-life. To achieve this goal, it is fundamental to understand how the materials’ properties change after recycling. This study aims to evaluate the thermal and mechanical properties of recycled plastics, namely polycarbonate (PC), polystyrene (PS), glass fibre-reinforced polyamide 6 (PA6-GF30), and polyethylene terephthalate (PET). With this purpose, injected samples were mechanically recycled twice and compared through thermal and mechanical tests, such as differential scanning calorimetry, hardness, tensile strength, and the melt flow rate. The results show that the amorphous materials used do not suffer significant changes in their properties but exhibit changes in their optical characteristics. The semicrystalline ones present some modifications. PET is the material that suffers the biggest changes, both in its flowability and mechanical properties. This work demonstrates that the mechanical recycling process may be an interesting possibility for recycling depending on the desired quality of final products, allowing for some materials to maintain comparable thermal and mechanical properties after going through the recycling process. Full article

(This article belongs to the Special Issue Advances in the Recycling, Processing and Use of Plastic Waste II)

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17 pages, 7861 KiB

Open AccessFeature PaperArticle

Blending Recycled High-Density Polyethylene HDPE (rHDPE) with Virgin (vHDPE) as an Effective Approach to Improve the Mechanical Properties

by Jian Zhang, Valerian Hirschberg and Denis Rodrigue

Recycling 2023, 8(1), 2; https://doi.org/10.3390/recycling8010002 - 26 Dec 2022

Cited by 18 | Viewed by 7831

Abstract

The mechanical properties of virgin/recycled high-density polyethylene (HDPE) blends over the complete concentration range was thoroughly investigated in this work. In particular, a focus was made on the long-term properties via mechanical fatigue. Two different mixing methods, namely powder mixing (dry blending) and [...] Read more.

The mechanical properties of virgin/recycled high-density polyethylene (HDPE) blends over the complete concentration range was thoroughly investigated in this work. In particular, a focus was made on the long-term properties via mechanical fatigue. Two different mixing methods, namely powder mixing (dry blending) and extrusion mixing (melt blending), were used to determine the effect of processing conditions on the tensile and fatigue behavior of the blends after compression molding. It was found that both tensile (modulus, ultimate strength) and fatigue performances were improved with increasing vHDPE content. Based on the obtained data, a correlation between the blends composition and mechanical properties is reported. Moreover, it was observed that increasing the vHDPE content led to slower crack propagation rate, probably due to less defects (contamination) in the blends. Finally, a negligible difference in mechanical properties (fatigue resistance) between both mixing approaches was observed, but samples produced via powder mixing showed less viscous dissipation (heat generation) as the vHDPE content increased, leading to lower surface temperature rise which can be an advantage for specific applications. Full article

(This article belongs to the Special Issue Advances in the Recycling, Processing and Use of Plastic Waste II)

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12 pages, 2718 KiB

Open AccessArticle

Washing Post-Consumer Flexible Polyethylene Packaging Waste

by Ezgi Ceren Boz Noyan, Abhijit Venkatesh and Antal Boldizar

Recycling 2022, 7(6), 90; https://doi.org/10.3390/recycling7060090 - 14 Dec 2022

Cited by 7 | Viewed by 3936

Abstract

The mechanical and thermal properties of injection-molded recycled polyethylene were studied, specifically with respect to the influence of large-scale washing and melt-compounding of polyethylene from post-consumer packaging waste. Three types of materials were studied: those taken after sorting, after sorting and washing, and [...] Read more.

The mechanical and thermal properties of injection-molded recycled polyethylene were studied, specifically with respect to the influence of large-scale washing and melt-compounding of polyethylene from post-consumer packaging waste. Three types of materials were studied: those taken after sorting, after sorting and washing, and after sorting, washing, and melt-compounding, including melt-filtration, all from a large-scale material flow. The materials were further processed on a laboratory scale and compared. The results showed that large-scale washing significantly reduced thermo-oxidative stability, as well as molar mass and melt viscosity. The degradation during large-scale washing made the material susceptible to further degradation in the subsequent extrusion compounding, as shown by the differences in compounding at 240 and 200 °C using a high-shear screw configuration. The compounding parameters, screw configuration, and compounding temperature did not influence the stiffness and strength of the unwashed and large-scale-washed materials, but the elongation-at-break varied, specifically, with the increased temperature. Washing had an influence on the mechanical properties as well, and the unwashed material provided molded samples with stiffness measurements of approximately 550 MPa, whereas the large-scale-washed material provided stiffness of approximately 400 MPa. The strength measurements were approximately 15 MPa for samples made of both unwashed and large-scale-washed material, and the elongation-at-break measurements were between 50 and 150%. The large-scale-washed and compounded materials had very different mechanical properties, with stiffness measurements of approximately 320 MPa, strength of approximately 20 MPA, and elongation-at-break of approximately 350%. The significantly different mechanical properties of the large-scale-washed and compounded materials were likely due to the melt-filtration included in the compounding through the removal of metal and rubber particles, and they may also have been due to the compatibilizing and stabilizing additive used in the compounding. Full article

(This article belongs to the Special Issue Advances in the Recycling, Processing and Use of Plastic Waste II)

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Review

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17 pages, 1161 KiB

Open AccessReview

An Overview of Management Status and Recycling Strategies for Plastic Packaging Waste in China

by Chaojie Yu, Diyi Jin, Xichao Hu, Wenzhi He and Guangming Li

Recycling 2023, 8(6), 90; https://doi.org/10.3390/recycling8060090 - 11 Nov 2023

Cited by 5 | Viewed by 6104

Abstract

Given their exceptional performance, plastic packaging products are widely used in daily life, and the dramatic expansion in plastic packaging waste (PPW) has exacerbated environmental problems. Many countries have enacted laws and developed recycling technologies to manage plastic packaging waste in consideration of [...] Read more.

Given their exceptional performance, plastic packaging products are widely used in daily life, and the dramatic expansion in plastic packaging waste (PPW) has exacerbated environmental problems. Many countries have enacted laws and developed recycling technologies to manage plastic packaging waste in consideration of the nature of PPW as both garbage and a resource. As the world’s largest producer and consumer of plastics, China has also taken measures to address this issue. This paper presents the latest management regulations and recycling strategies for PPW in China. Based on an analysis of the current management status of PPW and recycling technologies and their carbon emission impacts, some management suggestions and a comprehensive full-chain recycling process were put forward. We supposed that management challenges that need to be overcome in the future can be solved through the improvement of green designs for plastic packaging, manufacturing technology updates, consumption concept changes, and the high-value utilization of PPW. This paper aims to provide valuable references for government decisions on PPW management and, furthermore, to set up an economically sensible and industrially feasible PPW solution and boost the development of PPW recycling. Full article

(This article belongs to the Special Issue Advances in the Recycling, Processing and Use of Plastic Waste II)

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