Overview
ISO 1926:2009 - Rigid cellular plastics - Determination of tensile properties specifies a standardized method to measure how rigid cellular plastics behave under tensile stress. The standard defines specimen shapes, conditioning, test-machine requirements, test speed, data recording and calculation of tensile strength and elongation. It applies mainly to cellular materials with sufficient compression resistance to permit gripping; when gripping is not possible, the standard provides a variant using metal reinforcing plates.
Key topics and requirements
- Scope: Tensile testing procedure for rigid cellular plastics; variant for specimens that cannot be gripped (metal plates).
- Specimen shape and number: Test specimens follow the standard’s illustrated dimensions; at least five valid specimens are required. Specimens breaking outside the gauge length are rejected.
- Conditioning: Specimens must be conditioned per ISO 291. For precise measurement, a minimum of 6 hours at standardized atmospheres is specified (commonly 23 ± 2 °C and 50 ± 10 % RH).
- Test machine & clamps: Clamps must prevent slipping without introducing localized pressure damage. The movable grip rate is 5 ± 1 mm/min. Force measurement accuracy must be within ±1%.
- Extensometer: If used, it must exert minimal force and read gauge-length changes to 0.1 mm accuracy.
- Calculations: Tensile strength (kPa) is calculated from maximum force divided by the original cross-sectional area of the narrow section; elongation is expressed as percentage increase of original gauge length.
- Metal plate variant: Describes plate geometry, adhesive requirements (adhesive film shear strength greater than the material), and modified gripping arrangements when ends are reinforced.
- Precision: Interlaboratory data indicate typical repeatability ≈ 3% and reproducibility ≈ 10% for tensile measurements.
- Test report content: Must include reference to ISO 1926:2009, material description, conditioning, specimen type (note if metal plates used), number of specimens, orientation vs anisotropy, individual results and averages, stress–strain curve, deviations from the method and date.
Applications and users
ISO 1926:2009 is used by:
- Materials and R&D engineers evaluating new rigid cellular plastic formulations
- Quality control and testing laboratories certifying product mechanical properties
- Manufacturers of insulation panels, core materials, sandwich structures and other rigid foam products who need reproducible tensile-property data
- Procurement and compliance teams requiring standardized test evidence for specifications
Practical benefits include consistent tensile-property data for material selection, quality acceptance, and product development.
Related standards
- ISO 291 - Standard atmospheres for conditioning and testing (referenced for specimen conditioning)
- ISO 5725‑2 - Accuracy (trueness and precision) of measurement methods - Part 2 (used for interlaboratory precision analysis)
Keywords: ISO 1926:2009, rigid cellular plastics, tensile properties, tensile strength, extensometer, specimen conditioning, metal plates, tensile test method.