Location

La Jolla, CA

Start Date

1-1-1987 12:00 AM

Description

On-line process monitoring and control are prerequisites for more efficient and reliable manufacture of polymer matrix composites. The cure process involves complex chemical and physical changes that must be adequately controlled to consistently produce high quality products. Of various changes that occur, the viscosity is particularly important as it influences fiber wetting, uniformity of resin distribution and consolidation of the reinforcement plies. In the usual cure cycle, the viscosity of the resin initially decreases as the temperature of the resin rises owing to the higher temperature of the autoclave and heat released by the exothermic chemical reactions of the cross-linking process. Ultimately, the growing molecular weight of the polymer increases the viscosity beyond the range where flow will occur. If the resin viscosity becomes too low during this period, excess resin will seep out of the part producing an inferior product owing to resin deficiency. On the other hand, if the viscosity increases too fast the flow may be insufficient to achieve good consolidation of the plies.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

6B

Chapter

Chapter 6: Advanced Composites

Section

Processing

Pages

1287-1295

DOI

10.1007/978-1-4613-1893-4_146

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Process Monitoring of Polymer Matrix Composites Using Fluorescence Probes

La Jolla, CA

On-line process monitoring and control are prerequisites for more efficient and reliable manufacture of polymer matrix composites. The cure process involves complex chemical and physical changes that must be adequately controlled to consistently produce high quality products. Of various changes that occur, the viscosity is particularly important as it influences fiber wetting, uniformity of resin distribution and consolidation of the reinforcement plies. In the usual cure cycle, the viscosity of the resin initially decreases as the temperature of the resin rises owing to the higher temperature of the autoclave and heat released by the exothermic chemical reactions of the cross-linking process. Ultimately, the growing molecular weight of the polymer increases the viscosity beyond the range where flow will occur. If the resin viscosity becomes too low during this period, excess resin will seep out of the part producing an inferior product owing to resin deficiency. On the other hand, if the viscosity increases too fast the flow may be insufficient to achieve good consolidation of the plies.