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In-Situ Monitoring of Product Shrinkage During Injection Molding Using an Optical Sensor

Published

Author(s)

C L. Thomas, Anthony J. Bur

Abstract

We have used an optical fiber sensor for in-situ monitoring of product shrinkage during injection molding. The sensor, consisting of a bundle of optical fibers with a sapphire window at its end, is positioned in the ejector pin channel of the mold so that the sapphire window sits flush with the inside cavity wall. When the molded product shrinks, it separates from the wall and sapphire window, and establishes the geometry of a Fabry-Perot interferometer. During the molding of polystyrene, polypropylene and polyethylene, we observed optical interference fringes, and by counting fringes, a measurement of shrinkage was made.
Proceedings Title
Proceedings of the Society of Plastics Engineers Annual Technical Meeting
Volume
86
Conference Dates
May 1, 1999
Conference Location
New York, NY
Conference Title
Society of Plastics Engineers. Technical Meeting

Keywords

injection molding, interferometer, optical fiber sensor, polyethylene, polypropylene, polystyrene, process monitoring, shrinkage

Citation

Thomas, C. and Bur, A. (1999), In-Situ Monitoring of Product Shrinkage During Injection Molding Using an Optical Sensor, Proceedings of the Society of Plastics Engineers Annual Technical Meeting, New York, NY, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=851440 (Accessed June 14, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created December 31, 1998, Updated October 12, 2021