EN ISO 3377-2:2025 – Required Testing Instruments

EN ISO 3377-2:2025, titled “Leather – Physical and mechanical tests – Part 2: Determination of double edge tear load”, specifies a laboratory method to determine the tear strength of leather using a double-edged (Baumann) tear. The method is applicable to all types of leather and provides reproducible tear-load data for quality control, product specification, and comparative evaluation.

Test Principle

A rectangular leather specimen with a pre-cut shaped hole is mounted on steel holders of a tensile testing machine. The specimen is torn by the machine, and the maximum force required to propagate the tear is recorded. The process is repeated in different orientations relative to the leather backbone.

Specimen Preparation & Sampling

(1) Cut six test specimens according to ISO 2418: three with the long edge parallel to the backbone and three perpendicular.

(2) Condition specimens per ISO 2419 to ensure consistent moisture content and mechanical properties.

(3) Measure thickness at a specified point following ISO 2589 and calculate the mean thickness for reporting.

Required Instruments

(1) Tensile Testing Machine – Suitable force range and force-measuring accuracy of ±2 % (Class 2 per ISO 7500-1).

(2) Uniform Jaw Separation System – Ensures steady pulling at 100 mm/min ± 20 mm/min.

(3) Double-Edge Tear Holders – Steel strips 10 mm ± 0.1 mm wide, 2 mm ± 0.1 mm thick, bent at a right angle to secure the specimen.

(4) Press Knife / Cutting Device – For preparing uniform test specimens in a single operation.

(5) Analytical Tools – Thickness gauge or micrometer for measuring specimen thickness (ISO 2589).

(6) Data Recording System – Optional computer interface or force-displacement recorder to capture tear load in real time.

Test Procedure

(1) Mount the specimen on the steel holders.

(2) Start the tensile test, pulling the leather until the tear propagates fully.

(3) Record the maximum force during tearing for each specimen.

(4) Compute the mean tear load (N) for each orientation (parallel and perpendicular to backbone).

(5) Optionally, calculate mean tear strength (N/mm) by dividing the tear load by the mean thickness.

Data Reporting

Include the following in the test report:

(1) Reference to EN ISO 3377-2:2025.

(2) Mean specimen thickness.

(3) Mean tear loads for each orientation and overall mean.

(4) Mean tear strength (if applicable).

(5) Conditioning atmosphere, deviations from the method, test date, and sample identification.

Applications & Users

(1) Leather Manufacturers – Evaluate material suitability for end-use where tear resistance is critical.

(2) Quality Control Labs – Ensure batch consistency and detect defective materials.

(3) R&D Departments – Develop leather with enhanced mechanical performance.

(4) Footwear & Garment Producers – Assess leather for stress-prone areas in products.

(5) Upholstery & Automotive Suppliers – Compare materials and maintain contractual specifications.

(6) Procurement & Compliance Teams – Verify supplier quality and ensure standard adherence.

Related Standards

(1) ISO 2418 – Specimen positioning and preparation.

(2) ISO 2419 – Specimen conditioning and atmosphere.

(3) ISO 2589 – Thickness measurement.

(4) ISO 7500-1 – Calibration and verification of tensile machines (force accuracy).

(5) Other parts of ISO 3377 series – Complementary tear test methods.

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2026-01-06 17:19