Thermoplastic hybrid composites for sports applications

• Main Author: Ang, Yi Ci
• Other Authors: Sunil Chandrakant Joshi
• Format: Final Year Project
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering::Materials::Composite materials
• Online Access: http://hdl.handle.net/10356/74978
• Institution: Nanyang Technological University

Composite materials are used mostly in aerospace and automotive applications, but are increasingly accessible to the humble consumer, such as for sports applications in shoes, sports equipment and bicycle frames. As an established process, prepreg hand layup is the manufacturing process utilized by most manufacturers. Due to the increasing demand for composite usage in sports equipment, there is a need to increase the production of composite parts by automation and other alternative manufacturing approaches. There are many limitations with the usage of hand layup prepreg fabrication. Hand layup requires skilled labor for production of quality parts, this mean any changes in production volume will require additional manpower which takes time to procure, or to task existing workers with more work, both less than ideal. Also, additional equipment may be required for the curing of the parts, where expensive autoclaves are traditionally used. Including the cost of prepreg material which is much more expensive as compared to traditional material, this make it difficult for manufacturers to scale up production while being cost effective. Therefore, this project is going to explore an alternative manufacturing process, the usage of bladder resin transfer molding (BRTM), where the process has the potential of being automated, and providing flexibility in scaling of production by removing the need for skilled labor for production. Also, a new type of thermoplastic PMMA resin will be utilized, which has the ability to cure in room temperature and reduce capital costs further by removing the usage of a curing equipment such as an autoclave or a hot press. Experimentation for manufactured samples were investigated on samples made using prepreg hand layup process, BRTM process using thermosetting resin, and BRTM process using the PMMA thermoplastic resin to compare the flexural, impact, stiffness and vibration properties of the materials. It is discovered in most cases, BRTM epoxy resin process is similar or superior in mechanical properties as compared to prepreg epoxy hand layup process, such as the through-thethickness hoop compression test, where the BRTM process is able to absorb 9% more peak load as compared to the prepreg epoxy sample. However, the RTM-PMMA process produces part with superior properties measured from the 4 tests, such as an increase of 17.7% peak impact load as compared to RTM-epoxy process, and a 21.1% increase as compared to the prepreg epoxy process.