Although the environmental benefits of recycling plastics are well established and most geographic locations within the U.S. offer some plastic recycling, recycling rates are often low. Low recycling rates are often observed in conventional centralized recycling plants due to the challenge of collection and transportation for high-volume low-weight polymers. The recycling rates decline further when low population density, rural and relatively isolated communities are investigated because of the distance to recycling centers makes recycling difficult and both economically and energetically inefficient. The recent development of a class of open source hardware tools (e.g. RecycleBots) able to convert post-consumer plastic waste to polymer filament for 3-D printing offer a means to increase recycling rates by enabling distributed recycling. In addition, to reducing the amount of plastic disposed of in landfills, distributed recycling may also provide low-income families a means to supplement their income with domestic production of small plastic goods. This study investigates the environmental impacts of polymer recycling. A life-cycle analysis (LCA) for centralized plastic recycling is compared to the implementation of distributed recycling in rural areas. Environmental impact of both recycling scenarios is quantified in terms of energy use per unit mass of recycled plastic. A sensitivity analysis is used to determine the environmental impacts of both systems as a function of distance to recycling centers. The results of this LCA study indicate that distributed recycling of HDPE for rural regions is energetically favorable to either using virgin resin or conventional recycling processes. This study indicates that the technical progress in solar photovoltaic devices, open-source 3-D printing and polymer filament extrusion have made distributed polymer recycling and upcycling technically viable.
Key Findings[edit | edit source]
Table 1: Energy Demand and Reduction for Various Recycling Cases
| Case | Energy Demand (MJ/kg HDPE) | Percent Reduction (Δ%) for Distributed Recycling c |
| Distributed Recycling:
Insulated RecycleBot |
8.74 | -- |
| Virgin Resina | 79.7 | 89 |
| Centralized Recyclingb – Rural: Copper Harbor (monthly) | 28.4 | 69 |
| Centralized Recyclingb – Rural: Copper Harbor (bi-weekly) | 48.9 | 82 |
| Notes: a. [26], b. Estimate based on [24], c. Percent reduction = (Central-Distributed)/Central*100 | ||
See also[edit source]
RepRapable Recyclebot and the Wild West of Recycling[edit source]
Recycling Technology[edit source]
- Recyclebot
- RepRapable Recyclebot: Open source 3-D printable extruder for converting plastic to 3-D printing filament
- Open Source 3-D Filament Diameter Sensor for Recycling, Winding and Additive Manufacturing Machines
- Improving recyclebot concepts
- 3-D Printable Polymer Pelletizer Chopper for Fused Granular Fabrication-Based Additive Manufacturing
- Mechanical Properties of Direct Waste Printing of Polylactic Acid with Universal Pellets Extruder: Comparison to Fused Filament Fabrication on Open-Source Desktop Three-Dimensional Printers
- Fused Particle Fabrication 3-D Printing: Recycled Materials' Optimization and Mechanical Properties
- Multi-material distributed recycling via material extrusion: recycled high density polyethylene and poly (ethylene terephthalate) mixture
- Mechanical Properties and Applications of Recycled Polycarbonate Particle Material Extrusion-Based Additive Manufacturing
- Wood Furniture Waste-Based Recycled 3-D Printing Filament
- Solar powered distributed customized manufacturing
- Mechanical Properties of Ultraviolet-Assisted Paste Extrusion and Postextrusion Ultraviolet-Curing of Three-Dimensional Printed Biocomposites
- Open Source Waste Plastic Granulator
- Open-Source Grinding Machine for Compression Screw Manufacturing
- Sustainability and Feasibility Assessment of Distributed E-Waste Recycling using Additive Manufacturing in a Bi-Continental Context
- Finding Ideal Parameters for Recycled Material Fused Particle Fabrication-Based 3D Printing Using an Open Source Software Implementation of Particle Swarm Optimization
- Waste Plastic Direct Extrusion Hangprinter
- Hangprinter for Large Scale Additive Manufacturing using Fused Particle Fabrication with Recycled Plastic and Continuous Feeding
- Open Source Cold and Hot Scientific Sheet Press for Investigating Polymer-Based Material Properties
- Low-Cost Open-Source Melt Flow Index System for Distributed Recycling and Additive Manufacturing
Distributed Recycling LCA[edit source]
- Tightening the loop on the circular economy: Coupled distributed recycling and manufacturing with recyclebot and RepRap 3-D printing
- Technical pathways for distributed recycling of polymer composites for distributed manufacturing: Windshield wiper blades
- Plastic recycling in additive manufacturing: A systematic literature review and opportunities for the circular economy
- Energy Payback Time of a Solar Photovoltaic Powered Waste Plastic Recyclebot System
- Life cycle analysis of distributed recycling of post-consumer high density polyethylene for 3-D printing filament
- Evaluation of Potential Fair Trade Standards for an Ethical 3-D Printing Filament
- Life cycle analysis of distributed polymer recycling
- Distributed recycling of post-consumer plastic waste in rural areas
- Ethical Filament Foundation
- Green Fab Lab Applications of Large-Area Waste Polymer-based Additive Manufacturing
- Systems Analysis for PET and Olefin Polymers in a Circular Economy
- Potential of distributed recycling from hybrid manufacturing of 3-D printing and injection molding of stamp sand and acrylonitrile styrene acrylate waste composite
- Towards Distributed Recycling with Additive Manufacturing of PET Flake Feedstocks
Literature Reviews[edit source]
- Waste plastic extruder: literature review
- Life cycle analysis of polymer recycling literature review
- Solar powered recyclebot literature review
- Waste plastic extruder: literature review
- Life cycle analysis of polymer recycling literature review
Externals[edit source]
- Economist article on U. of Washington's HDPE boat, Oprn3dp.me
- https://ultimaker.com/en/resources/52444-ocean-plastic-community-project
- Another possible solution - reusable containers [1]
- Commercial https://dyzedesign.com/pulsar-pellet-extruder/
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- Cruz, F., Lanza, S., Boudaoud, H., Hoppe, S., & Camargo, M. Polymer Recycling and Additive Manufacturing in an Open Source context: Optimization of processes and methods. [2]
- Investigating Material Degradation through the Recycling of PLA in Additively Manufactured Parts
- Mohammed, M.I., Das, A., Gomez-Kervin, E., Wilson, D. and Gibson, I., EcoPrinting: Investigating the use of 100% recycled Acrylonitrile Butadiene Styrene (ABS) for Additive Manufacturing.
- Kariz, M., Sernek, M., Obućina, M. and Kuzman, M.K., 2017. Effect of wood content in FDM filament on properties of 3D printed parts. Materials Today Communications. [3]
- Kaynak, B., Spoerk, M., Shirole, A., Ziegler, W. and Sapkota, J., 2018. Polypropylene/Cellulose Composites for Material Extrusion Additive Manufacturing. Macromolecular Materials and Engineering, p.1800037. [4]
- O. Martikka et al., "Mechanical Properties of 3D-Printed Wood-Plastic Composites", Key Engineering Materials, Vol. 777, pp. 499-507, 2018 [5]
- Yang, T.C., 2018. Effect of Extrusion Temperature on the Physico-Mechanical Properties of Unidirectional Wood Fiber-Reinforced Polylactic Acid Composite (WFRPC) Components Using Fused Deposition Modeling. Polymers, 10(9), p.976. [6]
- Romani, A., Rognoli, V., & Levi, M. (2021). Design, Materials, and Extrusion-Based Additive Manufacturing in Circular Economy Contexts: From Waste to New Products. Sustainability, 13(13), 7269. https://www.mdpi.com/2071-1050/13/13/7269/pdf