ISO 1974 Tear (Elmendorf Method)

ISO 1974 Tear resistance specifies a method for determining the (out-of-plane) tearing resistance of paper. It can also be used for boards having a low grammage if the tearing resistance is within the range of the instrument.

This International Standard does not apply to corrugated fiberboard, but it may be applied to the components of such boards. It is not suitable for determining the cross-direction tearing resistance of highly directional paper (or board).

Principle

An initial cut is made in a test piece (of four superimposed sheets), which is then torn out-of-plane through a given distance along one single tear line using a pendulum. The work done in tearing the test piece is measured as the loss in energy of the pendulum.

The mean tearing force of a single sheet is calculated by dividing the work done by the distance torn and the number of sheets in a test piece.