One complete oscillation of the test piece, during which it is, folded first back wards and then forwards about the same line and this oscillation is double fold.
Two horizontally opposed and movable clamping jaws, which hold 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 120 double fold per minute. One or two specimen can be tested simultaneously. The number of folds is registered by two impluse / digital counter which are stopped automatically, when the specimen breaks. The Equipment is used for determining the Folding Endurance of all kinds of paper, foil and films upto 0.25 mm or less.