ISO 3386-1 covers the determination of material with a density up to 250 kg/m3. It also indicates a method for the calculation of the compression stress value of such materials.
The compression stress/strain characteristic is a measure of the load-bearing properties of the material. Two formulas allow to calculate the results. Part 2 refers to high density materials. Constitutes a minor revision of the first edition (ISO 3386/1-1979).
Scope and field of application
This part of ISO 3386 specifies a method for the determination of the compression stress/strain characteristic of low-density flexible cellular materials up to 250 kg/m3. It also indicates a method for the calculation of the compression stress value of such materials.
The compression stress/strain characteristic is a measure of the load-bearing properties of the material, though not necessarily of its capacity to sustain a long-term load.
The compression stress/strain characteristic differs from the indentation hardness characteristics (as determined in accordance with ISO 2439), which are known to be influenced by the thickness and the tensile properties of the flexible cellular material under test, by the shape of the compression plate and by the shape and size of the test piece.
ISO 3386/2 specifies a method for high-density materials and differs from part 1 in the following ways :
— it is mainly concerned with materials of density above 250 kg/m3;
— compression stress values have been deleted;
— it does not permit the use of a cylindrical test piece.
- ISO 1923, Cellular materials — Determination of linear dimensions.
- ISO 2439, Polymeric materials, cellular flexible — Determination of hardness (indentation technique).
For the purposes of this International Standard the following definitions apply.
compression stress/strain characteristic (CC): The stress, expressed in kilopascals*, required to produce a compression, at a constant rate of deformation during the fourth loading cycle of the test specified below, expressed as a function of the compression
compression stress value (CV40): The compression stress/strain characteristic for a compression of 40 %.