An optical technique for monitoring the solidification of thermoplastics in an injection moulding machine was implemented. The technique uses a He-Ne laser that illuminates the mould cavity, and a photomultiplier to measure the intensity of reflected light during the moulding cycle. Data from the sensor allows tracking the injection moulding cycle development. The measured light intensity is mainly influenced by refraction and reflection phenomena at the melt-solid interfaces during solidification. Reflection occurs primarily from the opposite mould wall but the reflection intensity is a complex composite of reflective scattering and refraction from crystallites, the mould wall and as many as six interfaces. The scattering caused by the opposite mould wall roughness also affects the light intensity. Plots of reflection intensity during the injection moulding cycle obtained for the three materials tested show similar patterns. Polystyrene, polypropylene and high-density polyethylene resins were used. The higher scattering power of semi-crystalline polyethylene and polypropylene reduces the reflection intensity values compared to the polystyrene plots. Further experimental and analytical work is required to use this technique for process control purposes.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.20924 |
| Date | January 1998 |
| Creators | Ramírez Domínguez, Edgar C. |
| Contributors | Patterson, W. I. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Engineering (Department of Chemical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001659099, proquestno: MQ50654, Theses scanned by UMI/ProQuest. |
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