ELASTOMERS 01 Long travel extensometer with 2713-002 self-tightening roller grips 02 2717 Series O-ring fixture 03 AVE 2 video extensometer for non-contacting strain measurement in a chamber 02
03
01
Grips and Fixtures When performing a tensile test on elastomers, maintaining clamping force is important to prevent slippage during the test to accommodate the materials’ thickness shrinkage during elongation. Instron’s 2712 Series pneumatic grips maintain a constant gripping force and accommodate any reduction in specimen thickness during testing. The gripping force itself can be selected by regulating the pneumatic pressure. 2713 Series self-tightening or 2713-006 thin film grips are also an excellent choice for elastomers, including very thin materials such as latex. Special fixtures are available for testing elastomeric O-rings. The 2717 Series O-ring test fixture rotates the specimen to avoid local stress concentrations while tension is applied. Elastomeric foams can be tested in tension using 2710 screw action or 2712 Series pneumatic grips or in compression with 2501 Series compression accessories. The 2810-130 foam compression fixture is specially designed to test elastomeric foams and features a self-aligning upper compression plate and perforated lower plate to allow air to be dissipated during testing.
Extensometry Strain measurement is often accomplished with crosshead travel, but this is less accurate due to elongation in the specimen tab ends as well as machine compliance. A more accurate method is to use a 2603 Series long travel extensometer, which provides direct strain measurement. For delicate specimens, the 2663 Series AVE 2 and SVE 2 video extensometers provide non-contacting strain measurement over a wide range of strains and are ideal for use at high or low temperatures in conjunction with 3119 Series environmental chambers.
Environmental 3119 Series environmental chambers test at non-ambient temperatures and can be coupled with a wide range of accessories. Pull rods, push rods and a range of suitable high and low temperature grips, such as 2732 Series pneumatic grips, are available.
Software Software for static testing of elastomeric materials is provided by Bluehill® Universal or Bluehill Elements.
www.instron.com/accessories 332
