Distributed recycling of waste polymer into RepRap feedstock

Purpose - A low-cost, open source, self-replicating rapid prototyper (RepRap) has been developed, which greatly expands the potential user base of rapid prototypers. The operating cost of the Rep Rap can be further reduced using waste polymers as feedstock. Centralized recycling of polymers is often uneconomic and energy intensive due to transportation embodied energy. The purpose of this paper is to provide a proof of concept for high-value recycling of waste polymers at distributed creation sites. Design/methodology/approach - Previous designs of waste plastic extruders (also known as RecycleBots) were evaluated using a weighted evaluation matrix. An updated design was completed and the description and analysis of the design is presented including component summary, testing procedures, a basic life cycle analysis and extrusion results. The filament was tested for consistency of density and diameter while quantifying electricity consumption. Findings - Filament was successfully extruded at an average rate of 90 mm/min and used to print parts. The filament averaged 2.805 mm diameter with 87 per cent of samples between 2.540 mm and 3.081 mm. The average mass was 0.564 g/100 mm length. Energy use was 0.06 kWh/m. Practical implications - The success of the RecycleBot further reduces RepRap operating costs, which enables distributed in-home, value added, plastic recycling. This has implications for municipal waste management programs, as in-home recycling could reduce cost and greenhouse gas emissions associated with waste collection and transportation, as well as the environmental impact of manufacturing custom plastic parts. Originality/value - This paper reports on the first technical evaluation of a feedstock filament for the RepRap from waste plastic material made in a distributed recycling device.