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Monitoring Resin Cure Of Medium Density Fiberboard Using Dielectric Sensors

Published online by Cambridge University Press:  10 February 2011

R. J. King
Affiliation:
KDC Technology Corp., 2011 Research Dr., Livermore, CA 94550
R. W. Rice
Affiliation:
Wood Science and Technology Dept., Univ. of Maine, Orono, ME, 04469
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Abstract

Flush mounted, in-press microwave (600–800 MHz) sensors have been developed for monitoring the complex permittivity in real time during the cure of medium density fiberboard. The measured dielectric constant (ε')a nd loss factor (ε") are independent diagnostic indicators of dynamic cure events that are catalyzed by heat, pressure and moisture. In particular, with this technique the instantaneous effects of resin viscosity, rate and degree of adhesive cure, the wood density, the changes in phase of the moisture and the rate of moisture depletion can be monitored during the entire curing process.

The comparative roles of moisture and adhesive content are discussed, along with the comparative modulus of rupture with cure duration. Results are presented comparing the dynamics of phenol-formaldehyde and isocyanate resins.

Type
Research Article
Copyright
Copyright © Materials Research Society 1996

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References

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