ASTM D3531

ASTM D3531 – Standard Test Method for Resin Flow of Carbon Fiber-Epoxy Prepreg

Description:

Significance and Use

5.1 This test method is used to obtain the resin flow of carbon fiber-epoxy prepreg tape, fabric or sheet material. It is suitable for comparing batches of material of supposedly the same characteristics and also for comparative evaluation of materials produced by different vendors using different resin-fiber combinations.

5.2 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 processing 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 material that will give reproducible results.

5.2.1 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, fabric or sheet.

5.2.2 As volatile content and degree of resin cure (advancement) change with time, this test method is useful in comparing the life of prepreg tape, fabric and sheet.

5.3 Method II has been introduced to match the test setup and procedure of SACMA SRM 22R-94: Determining the Resin Flow of Preimpregnated “B” Staged Material. This method should only be needed to conduct testing in a manner that aligns with the old SACMA method. Otherwise it is recommended to use Method I.

Scope

1.1 This test method covers the determination of the amount of resin flow that will take place from carbon fiber-epoxy prepreg material (fabric, tape or sheet) under given conditions of temperature and pressure.

1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.

1.2.1 Within the text, inch-pound units are shown in brackets.i et diam.