The ISO 1798 test method is used to investigate the strength and deformation properties of flexible cellular materials when a test piece is extended at a constant rate of displacement - until failure - to determine the
tensile strength and elongation at break. This test method is
suitable for use with flexible
cellular polymeric materials.
In principle, the test specimen is supported between two clamping jaws and is pulled apart
until the specimen fractures at a constant rate of displacement.
The load and strain is recorded during the test, and is used for determing the
tensile strength and elongation at break.
For this test, we use screw action grips, pneumatic action grips with rubber coated jaw faces for clamping of the material fitted to a tensile testing machine. This system is normally of single-column or dual-column table-top design. Two methods of strain measurement can be adopted.
A contacting long travel extensometer is attached to the test specimen. This incorporate a mechanism suitable for determining the relative change in length of the appropriate part of the test specimen. Or a non-contacting video extensometer can be used as a viewing mechanism suitable for determining the relative change in length of the appropriate part of the test specimen. We suggest using a materials testing software, such as Bluehill® 2, to input specimen details, set the desired test control, automatically calculate the desired results and statistics, and produce a test report all in accordance with the standard.
We suggest reviewing ISO 1798 to fully understand the test fixture and results requirements.