The lea strength of yarn is one of the major properties on which the suitability of yarn for its ultimate end use depends.
The test for determination of lea strength consists of making a lea from the yarn with the help of a warp reel and testing it on the lea strength tester, which registers the maximum load at which the lea starts unraveling.
The Lea Strength Tester is constructed on a study fabricated steel structure with a heavy base plate which can be directly placed on the ground. The lea is placed between two pins, one of which is moving and the other is attached to a load measuring arrangement. The moving pin is driven through a screw arrangement driven by a motor and a worm reduction gearbox. Provision has been made for automatically stopping the motor at the extreme positions of the moving pin. Two movable pins are provided, one for testing metric leas of 1 metre swift perimeter and the second for testing imperial leas of 1.5 yards swift perimeter.
IS 239 - 1951 : Method of Determination of Lea Breaking Load