TAPPI T 556Bending resistance of paper and paperboard (Lorentzen and Wettre type tester)
This procedure is used to measure the bending resistance of paper and paperboard in the machine and cross machine directions, by determining the bending resistance in mN of a 38mm (1.5in) wide vertically clamped sample, at 15o or 7.5o deflection. For this method, the standard bending angle is 15 degrees. For specimens that break or are otherwise unsuitable at 15 degrees, a bending angle of 7.5 degrees shall be used.