ISO 13937-1:2000

Overview

ISO 13937-1:2000 - "Textiles - Tear properties of fabrics - Part 1: Determination of tear force using ballistic pendulum method (Elmendorf)" - specifies the Elmendorf (ballistic pendulum) method to determine the tear force required to propagate a single-rip tear in textile fabrics. The standard is primarily applicable to woven fabrics (and some nonwovens with restrictions) and is not generally suitable for knitted, highly elastic, highly anisotropic or very loose fabrics.

Key topics and requirements

• Test principle: measure work done by a falling pendulum clamped to a specimen; maximum swing amplitude correlates to energy used to tear the fabric (commonly expressed as a force in newtons).
• Apparatus: ballistic pendulum testing machine with fixed and movable jaws, a knife for starting a slit, and a device to record maximum swing (mechanical or electronic). Metrological confirmation per ISO 10012-1 and calibration guidance referencing ISO 1974.
• Specimen geometry: tear length 43 mm ± 0.5 mm; starting slit 20 mm ± 0.5 mm; jaws separated ~3 mm to permit the knife. Clamping-face dimensions typically 30–40 mm wide and 15–20 mm high (not critical).
• Conditioning: specimens must be conditioned/tested in atmospheres specified by ISO 139.
• Sampling and preparation: cut two sets of specimens (warp and weft directions), at least five specimens per direction, avoiding selvedges and defects; no specimen within 150 mm of fabric edge.
• Operation & acceptance:
  • Select pendulum mass so results fall between 15% and 85% of instrument full-scale.
  • Readings normally in newtons; calculate arithmetic mean and round to two significant figures.
  • Test validity criteria include no thread slippage, no clamp slippage, and tear contained within the notched area. If ≥3 of 5 specimens are rejected, the method is unsuitable.
• Reporting: include reference to ISO 13937-1 and key test conditions, directions tested, mean tear force, and optional statistics (coefficient of variation, min/max, 95% confidence limits).

Applications and users

• Practical use: quality control, incoming material inspection, R&D, product specification and acceptance testing for apparel, home textiles, industrial textiles, technical fabrics and protective textiles.
• Typical users: textile test laboratories, manufacturers, quality engineers, product designers, procurement/specification writers, and standards bodies seeking reproducible measures of tear resistance.

Related standards

• ISO 139 - Standard atmospheres for conditioning and testing
• ISO 1974 - Paper tearing resistance (Elmendorf) (calibration reference)
• ISO 10012-1 - Metrological confirmation for measuring equipment
• ISO 13937 parts 2–4 - Other tear methods (trouser, wing, tongue)
• ISO 4674, ISO 9073-4 - Related methods for coated fabrics and nonwovens

Keywords: ISO 13937-1, Elmendorf method, ballistic pendulum, tear properties, tear force, textiles testing, tear resistance, fabric testing.