Design and Build a Tool to Recycle Plastic Bottle Waste into 3D Printing Filament

Abstract

This study aims to design, develop, and evaluate the performance of a prototype device for recycling PET plastic bottle waste into filament material. The research employed a Research and Development (R&D) method using the V-Model approach, consisting of nine stages: Requirement Analysis, System Design, Architectural Design, Module Design, Coding, Unit Testing, Integration Testing, System Testing, and Final Verification. The prototype integrates an ESP32 as the main controller, an REX-C100 for heater temperature control, a K-type thermocouple and MAX6675 for temperature monitoring, an E18-D80NK reflective infrared sensor for detecting the material output, and a DC gear motor with an L298N driver as the pulling mechanism. An I2C 20×4 LCD, Blynk, and ESP32-CAM are also incorporated as monitoring systems. The material used was a 9 mm-wide PET sheet weighing 19.5 g, obtained from a single 1,500 mL Vit PET bottle. The test results showed that the device successfully produced 5.47 m of filament with a final mass of 17.7 g, resulting in a mass loss of 1.8 g (9.23%) and a yield of 90.77%. The resulting filament diameter was 1.72 mm, with a difference of 0.03 mm from the target diameter of 1.75 mm. The E18-D80NK sensor achieved a 100% detection success rate at distances of 1–4 cm, while the K-type thermocouple and MAX6675 exhibited a reading difference of 0.0–0.6 °C compared with an infrared thermometer. Printing tests using an Ender 3 Max demonstrated that the filament could be extruded and used to print a cube object. Surface quality, dimensional accuracy, mechanical and thermal properties, moisture content, interlayer adhesion, and long-term printing performance were not evaluated.