{"id":9867,"date":"2026-02-24T15:11:46","date_gmt":"2026-02-24T07:11:46","guid":{"rendered":"https:\/\/www.packqc.com\/standard\/iso-1974-2\/"},"modified":"2026-04-16T09:54:21","modified_gmt":"2026-04-16T01:54:21","slug":"iso-1974","status":"publish","type":"standard","link":"https:\/\/www.packqc.com\/nn\/standard\/iso-1974\/","title":{"rendered":"ISO 1974"},"content":{"rendered":"

How ISO 1974 Defines Tearing Resistance<\/h2>\n\n\n\n

The standard describes a sequence in which the operator places four superimposed sheets into an Elmendorf pendulum tester<\/a>, introduces an initial cut, and allows the pendulum to tear through a defined distance. The energy lost by the pendulum<\/strong> represents the work required to propagate the tear. From this, laboratories calculate the mean tearing force per sheet.<\/p>\n\n\n\n

The standard applies mainly to paper and lightweight boards whose tearing resistance falls within the capability range of Elmendorf-type instruments. ISO 1974 recommends selecting a pendulum capacity that ensures readings remain between 20% and 80% of the tester\u2019s scale, maximizing accuracy and repeatability.<\/p>\n\n\n\n

Why Tearing Resistance Matters<\/h2>\n\n\n\n

The tear strength of paper directly influences converting performance, packaging integrity, and end-use durability. Insufficient resistance often results in web breaks, poor runnability, or consumer complaints. Conversely, excessive resistance may hinder operations such as opening features, creasing, or perforation. ISO 1974 offers a reliable measurement framework that helps balance these requirements.<\/p>\n\n\n\n

Key Principles of the Elmendorf Tearing Method<\/h2>\n\n\n\n

Controlled Tear Propagation<\/h3>\n\n\n\n

ISO 1974 uses a single tear line<\/strong> created after firmly clamping the stacked sheets. By standardizing sheet count, tear distance, and pendulum motion, the test isolates the tearing property rather than the influence of operator technique.<\/p>\n\n\n\n

Pendulum and Mass Selection<\/h3>\n\n\n\n

The tear value should fall in the recommended operating range. Working outside the range increases test uncertainty. Modern instruments simplify this selection with modular or automatically recognized pendulum masses.<\/p>\n\n\n\n

Data Quality and Reporting<\/h3>\n\n\n\n

ISO 1974 calls for separate reporting of tearing resistance in both directions, including the coefficient of variation. Digital reporting systems help teams reduce transcription errors, preserve traceability, and accelerate root-cause analysis during quality investigations.<\/p>\n\n\n\n

Choosing Right Elmendorf Tester from Cell Instruments<\/h2>\n\n\n\n

Paper and packaging laboratories aim for instruments that deliver precision, durability, and data assurance<\/strong>. The Cell Instruments SLD-01 Tearing Tester aligns closely with the operational expectations established by ISO 1974 and strengthens laboratory workflow efficiency.<\/p>\n\n\n\n

Key advantages include:<\/p>\n\n\n\n