Instruments as per ASTM D689
Standard Method to test Internal Tearing Resistance of Paper
The standard method measures the force perpendicular to the plane of the paper required to tear multiple sheets of paper through a specified distance after the tear has been initiated, using an Elmendorf-type tearing tester. The results can be used to compute the approximate value of tearing resistance of a single paper. In such case, tearing a single sheet of paper, the tearing resistance is measured easily and directly.
Tearing is a common property of failure of many materials like rubber, textile and paper. We also know that materials differ in their ability to tearing, some materials are quite resistant to tearing in nature when they are in their full form, but at the same time when small cut is made......