Folding Endurance Tester

Two horizontally opposed and movable clamping jaws, which hold a specimen 100 mm (4 in.) long under variable tension during the folding cycle, while a slotted folding blade, sliding back and forth between four creasing rollers, folds the paper at 105-125 double folds per minute. The clamps are supported from below on rollers and, while in motion, are freely suspended between tension springs. The folding blade is 0.50± 0.0125 mm (0.020±0.0005 in.) wide, the slot extending somewhat above and below the normal position of the test specimen.
Details :

• The vertical edges of the slot are cylindrical with radius equal to half the thickness of the blade. The four creasing rollers, each 6mm (approximately ¼ in.) diameter and 18 mm (approximately ¾ in.) long, are arranged symmetrically about the mid position of the folding slot and are provided with antifriction or jeweled bearings.
• 6 digit mechanical Counter, to register the number of double folds and to stop the instrument when the specimen breaks with reset knob to make it zero.