Category: Composite

ASTM D3330

Standard Test Method for Peel Adhesion of Pressure Sensitive Tape (Test Methods A&F)

This method determines the peel adhesion of pressure-sensitive tapes, and includes 6 methods.  Method A measures adherence when peeled at a 180° angle to a standard steel panel or other surface of interest.  Method B measures the adherence to the backing of a single-coated tape. Method C measures the adherence of double-coated tape to a steel panel or any other surface of interest.  Method D measures the adherence of the release liner to the adhesive of either a single or double coated tape.  Method E measures adherence of a transfer tape to a steel panel or other surface.  Method F measures the adherence when peeled at a 90° angle to steel or another surface.

Specimens are prepared to standard on approved substrates and then tested using a constant extension test frame and appropriate load cell.  Depending on the method desired by the customer, a simple substrate and grips can be used or a specific fixture that employs rollers and cables to keep the peel at a specific angle from the substrate.

Peel strength, dwell time, and adhesive failure type.

Equipment Used:
Solvents for condition include Diactone alcohol, methanol, mehyl ethyl ketone, n-heptane, or acetone; test frame, wedge grips, 90° peel fixture.

ASTM D3039

Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials

This test is designed for testing polymer matrix composite materials.  It is used to measure the force required to break the material, and the extent to which it elongates to the breaking point.   A stress-strain diagram is produced from the extracted data, and is used to determine the modulus, yield, and fracture point.  The material can be conditioned to be tested at varying temperatures and environmental conditions according to the client’s specifications.

The specimen is prepared by machining to a size specified in the ASTM standard and then conditioned according to the client’s specifications. Prior to beginning the test, the machine is set to the starting gauge length, as per the standard, then inserted in the appropriate gripping fixture. The testing engineer then inputs relevant dimensional and material criteria into the software.  The specimen is finally pulled at a constant rate of extension, or load, and the software produces a stress-strain diagram.  Multiple specimens are usually tested to show material property consistency.

Tensile strength, modulus of elasticity, tensile strain, transition strain, Poisson’s ratio.

Test frame, extensometers, strain gauge, test method software.

ASTM D2344

Standard Test Method for Short-Beam Strength of Polymer Matrix Composite Materials and Their Laminates

This test is used for determining the interlaminar shear strength of parallel fibers.  Applicable for reinforced plastics and composites, the data is used for purposes concerned with interplay strength and comparing composite materials.

After conditioning and machining to appropriate specifications, the specimen is placed on a horizontal shear test fixture such that the longitudinal axis is perpendicular to the loading beam.  The support span is set to reflect a ratio of the thickness of the specimen. The nose applies load to the specimen until breakage.

Short-beam shear strength.

Equipment used:
Test frame, Short beam shear three-/four-point test fixture, test method software.