Leather — Physical and Mechanical Tests — Determination of Tear Load

Part 2: Double Edge Tear

ISO 3377-2 specifies a method for determining the tear strength of leather using a double edged tear.

The method is sometimes described as the Baumann tear.

It is applicable to all types of leather.

Principle

A rectangular test piece with a hole of specified shape is placed over the turned up ends of a pair of holders attached to the jaws of a tensile testing machine.

The highest force exerted during tearing of the test piece is recorded.

 Apparatus

Tensile testing machine, with:

a force range appropriate to the specimen under test;

a means of recording the force to an accuracy of at least 2 % as specified by Class 2 of ISO 7500-1;

a uniform speed of separation of the jaws of 100 mm/min ± 20 mm/min.

Test piece holders

Each consisting of a strip of steel 10 mm ± 0,1 mm wide and 2 mm ± 0,1 mm thick, bent through a right angle at one end to form a rigid strip with a minimum

length of 12 mm ± 0,1 mm.

The holders either fit into or replace the jaws of the tensile testing machine.

*** Before conducting ISO 3377-2 , it is important to read the entire specification. Standards can be obtained from appropriate standard authorities.