Design and Development of an Automated PET Plastic Bottle 3D Printer Filament Making Machine

Abstract The aim of this project is to develop an automated machine to make 3D printer filament using PET plastic bottle. The first part of the machine is a bottle cutter through which smoothed surface PET bottle is cut to strip ribbon like shape, and this goes into the second part of the machine which is a heating block with a nozzle to extrude filament of around 1.75mm diameter, powered using a power supply and its temperature automatically controlled using an Arduino Nano. Two experiments were also carried out using this system to study the effects of varying PET strip widths and heating temperature on the extruded filament, which showed that increased PET strip width requires higher temperature for extrusion and increased temperature results in thinner diameter of filament. A bottle cut to 10mm width strips and extruded at 240°C was found to be the best setting for an optimal filament extrusion. This was used to 3D print DIN 53504 tensile specimens which was tested to get the material properties, where the yield stress of recycled PET was found to be 32.93MPa, and its elastic modulus 2937.98MPa.