Design and fabrication of a vacuum forming machine

• Main Author: Ang, Hwee Min
• Other Authors: Sellakkutti Rajendran
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/78358
• Institution: Nanyang Technological University

Dental aligners are a form of orthodontic device that aims to be a substitute for traditional wire braces. This report will detail the design and fabrication of a vacuum forming machine to be used for the fabrication of such aligners. The objective of the project is to produce a vacuum forming machine that is equivalent or even better than commercially available machines, while being priced affordably. This report covers the research done on existing designs on the market, their limitations and the design process used to create the vacuum former for this project. The final design of the vacuum former produced for this project consists of a stationary base with a vacuum chamber in which a mould is placed. Next, the thermoplastic sheet is placed on the top of this base, covering the vacuum chamber. A sheet metal plate is then placed on the sheet and then clamped at the four ends. A heat gun which acts as the heating element is placed in a holder capable of vertically and is used to heat the plastic sheet. Once deformation in the plastic sheet is of an acceptable level, a vacuum pump is turned on to form the sheet over the mould. Variables such as heating temperature and heating time are used in experiments to obtain dental aligners of varying quality. Subsequently, the values are analyzed to find the range of values capable of producing the aligner with the best finish.