Overview
ISO 1974:2012 - "Paper - Determination of tearing resistance - Elmendorf method" specifies a laboratory test method for measuring the out-of-plane tearing resistance of paper using the Elmendorf pendulum. The standard applies to paper and to low-grammage boards when their tearing resistance is within the instrument range. It excludes corrugated fibreboard as a whole (though components may be tested) and is not suitable for measuring cross-direction tearing of highly directional papers.
Key topics and technical requirements
- Test principle: A pre-cut test piece (typically a pack of four superimposed sheets) is torn out-of-plane by a pendulum; the loss of pendulum energy gives the work done in tearing and the mean tearing force per sheet.
- Units and indices: Tearing resistance is reported in millinewtons (mN). The tear index is calculated by dividing tearing resistance by grammage (expressed as mN·m²/g).
- Apparatus: An Elmendorf-type tear tester with:
- Pendulum(s) or interchangeable weights (recommended capacities: 2 000, 4 000, 8 000, 16 000 mN),
- Two clamping jaws (clamping widths typically 25 mm or 36 mm),
- A cutting knife for the initial slit and a mechanism to register maximum swing or direct tear readings.
- Test pieces and preparation:
- Test pieces are usually four rectangular sheets with untorn length of 43.0 ± 0.5 mm.
- Cut sheets with edges parallel to the test direction; avoid folds, creases or damage.
- Minimum of 10 valid readings per principal direction (machine and/or cross).
- Conditioning and sampling: Samples must be conditioned and tested in the standard atmosphere per ISO 187; sampling according to ISO 186; grammage per ISO 536.
- Calibration and precision: Instruments must be adjusted and calibrated (Annexes A and B) and precision data are provided (Annex C).
Practical applications and users
- Who uses it:
- Paper and board manufacturers for quality control and specification compliance.
- Converters, packaging designers and testing laboratories assessing tear performance for handling, processing and end-use durability.
- R&D teams comparing raw materials, coatings or treatments that influence tear properties.
- Typical uses:
- Specifying material performance for printing, packaging, envelopes and labels.
- Troubleshooting converting/process defects where tear resistance affects runnability.
- Material selection where out-of-plane tear behaviour is critical.
Related standards
- ISO 186 - Sampling to determine average quality
- ISO 187 - Standard atmosphere for conditioning and testing
- ISO 536 - Determination of grammage
ISO 1974:2012 is the authoritative Elmendorf tear test procedure for consistent, comparable tearing-resistance data in paper and low-grammage board testing. Keywords: ISO 1974:2012, Elmendorf method, tearing resistance, Elmendorf-type tear tester, tear index, paper testing, paper and board.
