03/22/2024
By Danielle Fretwell

The Francis College of Engineering, Department of Plastics Engineering, invites you to attend a Master's Thesis defense by Nikith Lalwani on: Development of thermoplastic polyurethane foams using material extrusion additive-manufacturing process.

Candidate Name: Nikith Lalwani
Degree: Master’s
Defense Date: Friday, April 5, 2024
Time: 10:30 a.m. to 12:30 p.m.
Location: Perry Hall 109

Committee:

  • Adivisor Amir Ameli
  • Akshay Kokil
  • Jay Park

Brief Abstract:

This thesis investigates the innovative utilization of the material extrusion additive manufacturing (MEXAM) process to produce thermoplastic polyurethane (TPU) foams tailored for a wide array of industrial applications. It begins with an introduction to additive manufacturing and showcases the broad application of TPU foams in consumer and commercial products due to their elastic, flexible, and lightweight nature.

It then explores the development of 3D-printed TPU foams employing thermally expandable microspheres (TEM). The study starts with screening printing trials to assess the overall printing quality and the range of densities that are achievable in the printed foams under various printing conditions. The work further employs a statistical design of experiment approach in an attempt to find printing process design that provides maximum foam expansion during 3D printing. By methodically varying process parameters, such as flow rate, layer height, nozzle temperature, and nozzle diameter, the study aims to understand the effect of each parameter as well as their interactions with one another on foam density and compressive behavior, providing valuable insights into optimizing MEXAM processes for foam fabrication.

Later, a case study investigates the possibility of alternative material systems for helmet padding applications. The research targets the printing of low-density foams that matches the performance of commercially available foam pads, as to provide customized and optimized pad geometries with potentially superior performance.

Finally, it explores the suitability of 3-D printed TPU foams for insole applications in footwear. Through a comprehensive assessment of various physical and mechanical properties, the study showcases AM's capability to fabricate customized foam components with properties comparable or superior to traditional materials and fabrication methods, thereby providing more flexibility in design and manufacturing for footwear industry.

In summary, this thesis contributes to advancing the understanding and application of MEXAM in foam fabrication of elastomeric materials, paving the way to transform foam manufacturing processes and product design, enabling enhanced performance, functionality, and customization in a range of applications.