NDTnet 1998 Aug, Vol.3 No.8

Full-Text - Abstract

Generally plastics are classified under three main headings - thermoplastics, thermosets and elastomers (rubber based materials). The thermoplastics are linear polymers and flow with the application of heat. They have the ability to be reheated and reformed. Thermosets, however, on application of heat set or cure in an irreversible chemical reaction known as cross-linking. This chemical reaction prevents renewed softening.

The degree of curing determines the quality of the thermosetting products. In current use the curing is determined after the technological process, for instance by boiling the thermosetting elements in dye solution. The degree of coloration is used as a measure of cure, to show whether the material is for example undercured or overcured.

For the curing measurement of epoxy resins ultrasonic technique is known. This technique was used for on-line curing control of moulding compounds during compression or injection moulding. For that purpose an measurement equipment with high-temperature, high-pressure stable sensors was developed. This equipment was tested on industrial conditions and has been commercially available.

The possibilities of the above mentioned technique are illustrated with practical results.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

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