1.1 This test method covers the dynamic mechanical instrumentation for determination and reporting of the thermal advancement of cure behavior of thermosetting resin on fiber in a laboratory. It may also be used for determining the cure properties of filled resins and resins without reinforcements. These encapsulated specimens are deformed in torsional shear using dynamic mechanical methods. 1.2 This test method is intended to provide the means for determining the cure behavior of thermosetting resins on fibers over a range of temperatures from room temperature to 250C by forced-constant amplitude techniques (in accordance with Practice D4065). Plots of modulus, complex viscosity, cure behavior, tan delta, and damping index as a function of time/temperature quantify the thermal advancement or cure characteristics of a resin or a resin on fiber. 1.3 This test method is valid for a wide range of frequencies typically from 0.002 to 50 Hz. NOTE 1--It is recommended that low-frequency test conditions, generally 1 to 2 Hz, will generate more definitive cure-behavior information. 1.4 If available, use compliance compensation in the instrument to improve the accuracy of the data as the modulus builds during cure. 1.5 Test data obtained by this test method are relevant and appropriate for optimizing cure cycles. 1.6 The values stated in SI units are to be regarded as the standard. 1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
This test method is necessary to provide a better means of characterizing the cure properties of prepregs. The use of mechanical properties also provides onfididence that the prepreg will produce the correct modulus in the part after cure.
Keywordscure behavior; flow; rheological; thermosetting resins; viscosity; prepregs; composites; dynamic; complex viscosity; storage shear modulus; viscous shear modulus
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top
Approval On Hold
Ballot Item Approved as D7750-2012 and Pending Publication