The flexometer Bally is intended to determine the resistance of a material to cracking or other types of failure at flexing creases.
The method is mainly applicable to all flexible materials and in particular leathers and coated fabrics used in footwear uppers.
To perform the test one end of the specimen is held in an upper clamp with the grain surface folded inwards so that these surfaces touch and the fold line is horizontal. It is then turned inside out and bent through 90° before being inserted in the lower clamp. In this clamp, therefore, the specimen is held flesh to flesh and the fold line is vertical. Oscillation of the upper clamp 22,5° at 100 flexes per minute during the test then causes the point of transition from inward to outward fold to run up and down the test piece, producing cracking of the coating and in the case of leather possibly a hole right through the material.
The front panel of the flexometer Bally has one counter to program the total number of cycles to perform during the test and four buttons with the functions of: Power, Start, Stop and Emergency.
A special model to perform flexing test according to Standard UNI 4818 at room temperature and subzero is also available on request.