# OPTICAL TRANSPARENCY CHANGE METHOD FOR CURE MONITORING OF GFRPs

> Title: OPTICAL TRANSPARENCY CHANGE METHOD FOR CURE MONITORING OF GFRPs Page Range: p.63-71 Author(s): Akira Todoroki; Norihiko Hana File size: 261K Download the pdf (subscribers only) Buy the pdf (non-subscribers) Journal: Polymers and Polymer Composites Issue Year: ppc Volume: 17 Issue No:...

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Published: 2009-02-01T00:00:00+00:00
Categories: Polymers and Polymer Composites

**Title: OPTICAL TRANSPARENCY CHANGE METHOD FOR CURE MONITORING OF GFRPs**
 Page Range: p.63-71
 Author(s): Akira Todoroki; Norihiko Hana
 File size: 261K
 ![](http://dload.gif) [Download the pdf](http://journals.asp?Page=111&JournalDownload=ON&JournalType=ppc&JournalIssue=ppc17-2&JournalID=100802&JIP=) (subscribers only)
 ![](http://handbuy.gif) Buy the pdf (non-subscribers)
 Journal: Polymers and Polymer Composites
 Issue Year: ppc
 Volume: 17
 Issue No: No.2

**Abstract**
 The resin transfer molding(RTM) process is becoming popular for low-cost fabrication of complex commercial products made from GRP. As regards the RTM process for complex components, the optimal fabrication process is found by repeated trial and error. This process is time-consuming and one of the reasons for the high cost of composite products. To overcome this problem, it is useful to monitor the degree of cure of target GRP products. In this study, the luminance change method was used for cure monitoring of polyester-based GRP composites. Polyester resin usually changes its optical transparency during the curing process, which enabled the degree of cure to be monitored by measuring the luminance change of light or reflected light. A system that measured reflected light was developed. The sensing system employed a light-emitting diode as the light source and a photodiode as a light power sensor. This low-cost cure monitoring system was applied to the monitoring of the degree of cure in GRPs and was achieved using commercially-available dielectric sensors. Results were compared with the results of luminance change. The effectiveness of this method was confirmed experimentally. 10 refs.

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