This test method is used to obtain the resin flow of carbon fiber-epoxy prepreg tape or sheet material. It is suitable for comparing lots of material of supposedly the same characteristics and also for comparative evaluation of materials produced by different vendors using different resin-fiber combinations.
Composite parts are laminated from prepreg material at various pressures and temperatures. Production process design will require a flow test be run at a temperature and a pressure close to that of the actual molding conditions. All methods of measuring resin flow are dependent on the size and geometry of the specimen. This test method uses the smallest quantity of tape that will give reproducible results.
The percent resin flow of a single fiber and resin system at a temperature and pressure varies with the volatile content, degree of advancement of epoxy resin, and with the resin content of the prepreg tape or sheet.
As volatile content and degree of resin cure (advancement) change with time, this test method is useful in comparing the life of prepreg tape and sheet.