{"id":7608,"date":"2025-12-10T17:05:57","date_gmt":"2025-12-10T09:05:57","guid":{"rendered":"https:\/\/www.qualitester.com\/?page_id=7608"},"modified":"2025-12-11T10:06:03","modified_gmt":"2025-12-11T02:06:03","slug":"iso-1974","status":"publish","type":"page","link":"https:\/\/www.qualitester.com\/tr\/standards\/iso-1974\/","title":{"rendered":"ISO 1974"},"content":{"rendered":"

ISO 1974 Tearing Resistance of Paper
\nElmendorf Tear Method<\/small><\/h1>\n
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ISO 1974 defines the internationally recognized method for measuring the tearing resistance of paper using the Elmendorf pendulum system. This standard supports accurate evaluation of paper tear strength<\/strong>, enabling paper manufacturers, converters, and quality control laboratories to quantify how a sheet behaves when subjected to out-of-plane tearing forces. In industries where runnability, durability, and converting stability matter, a clear understanding of ISO 1974 provides the basis for consistent material performance and process optimization.<\/p>\n

This method is widely applied to printing papers, packaging grades, tissue, specialty papers, and low-grammage boards. It also connects directly with quality indices such as the tear index, which combines tearing force with grammage to express strength efficiency.<\/p>\n

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Tearing Resistance of Paper and Its Importance in ISO 1974 Testing<\/h2>\n

Bu tearing resistance of paper<\/strong> reflects how well a sheet withstands the propagation of a pre-cut tear. It is a critical indicator in applications such as packaging line performance, bag and envelope durability, and printing press reliability. ISO 1974 provides a structured approach to measure this property in a way that minimizes operator influence and ensures global comparability.<\/p>\n

ISO 1974 specifies that the test uses four superimposed sheets with an initial slit. A pendulum tears the sheets over a defined distance, and the energy lost by the pendulum translates to tearing force. This direct link between work done and material resistance makes the method reliable across diverse paper types.<\/p>\n

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Elmendorf Tear Test Principles and Measurement Approach<\/h2>\n

Bu Elmendorf tear test<\/strong> is the core of ISO 1974. Its methodology revolves around consistent mechanical action and precise quantification of energy loss.<\/p>\n

Key steps include:<\/p>\n

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  1. Preparing ten test pieces from conditioned samples<\/li>\n
  2. Selecting the appropriate pendulum range so that the expected mean falls between 20% and 80% of the full scale<\/li>\n
  3. Positioning four sheets in the clamps, ensuring the slit aligns centrally<\/li>\n
  4. Releasing the pendulum to drive the tear through a controlled distance<\/li>\n
  5. Recording tearing resistance or scale readings<\/li>\n
  6. Confirming that tear deviation stays within allowed limits<\/li>\n
  7. Calculating tearing resistance per sheet and, if required, the tear index<\/li>\n<\/ol>\n

    The standard also provides equations for direct tearing resistance readings as well as for scale-based readings with a pendulum factor. These calculations allow machine-direction and cross-direction strength evaluations, which are essential for diagnosing fiber orientation and refining process conditions.<\/p>\n

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    Paper Tear Strength Test Applications Across Industries<\/h2>\n

    Bu paper tear strength test<\/strong> provides insights that influence:<\/p>\n