Design and development of a polyester yarn production machine using recycled polyethylene terephthalate (pet) bottles/ Sofia Margarette D. Cepeda, Reena D. Miranda, Louise Nicole R. Montes, Aaron Radjabel C. Santos, and Chariza Mae S. Santos.--

Bachelor's thesis

College Of Engineering.--
Bachelor of science in mechanical engineering: Technological University of the Philippines,
2025.

Includes bibliographic references and index.

This study aimed to design, develop, and evaluate a prototype machine capable of
producing monofilament polyester yarn from 200 grams of recycled polyethylene
terephthalate (PET) bottle waste. The machine integrated key processes melting, rolling,
and winding into a compact system for small-scale and community-level recycling
applications.
A developmental research design with a prototyping methodology was employed.
The process began with the conceptualization and technical design of the machine,
followed by the fabrication and assembly of essential components such as a 200g-capacity
hopper, temperature-controlled heating bands (180°C to 220°C), an extruder screw with a
barrel, rubber rollers, a water-cooling system, and an engineering plastic winder.
Test runs demonstrated the machine's ability to produce approximately 11 meters
of 1 mm diameter polyester yarn from 0.5 kg of PET in 1 hour and 15 minutes per batch.
However, the tensile strength of the yarn averaged only 0.27 × 10−3 MPa below the
industrial standard making it suitable only for light-duty applications. An economic
analysis revealed that the machine has a 30.93% return on investment (ROI) in its first year,
with a break-even time of approximately 3.23 years.
The study concluded that the prototype machine is technically feasible,
operationally efficient, and economically viable for small-scale PET waste recycling into
yarn. The project offers a sustainable solution to plastic waste management and contributes
to promoting circular economy practices.