Determination of Shrinkage and Modulus Development of Thermosetting Resins

A new method for the determination of shrinkage and modulus development of thermoset resins is described. The method uses the change in the time of travel of longitudinal ultrasonic waves in a couplant to determine the change in height of a column of resin. This change in height is used to determine shrinkage. The method also uses the time of travel of ultrasonic waves through a column of resin to determine the modulus of the resin. The technique allows continuous monitoring of shrinkage and modulus as the material changes from the liquid state to the solid state. This method is used to determine the shrinkage and modulus development for a common epoxy resin.