The bending resistance of paper affects many converting operations and most end-users. The bending resistance of paperboard is basic to many of the uses into which this material is placed. It is necessary to have a convenient, reproducible test method to measure this fundamental characteristic.

1.1 This test method determines the bending resistance of paper, paperboard, and other flexible flat-sheet materials by measuring the force required to bend a specimen under controlled conditions. The instrument described allows for a wide variation in specimen length, width and applied force.

1.2 This test method is not recommended for soft, limp or creped materials. Materials such as tissue or toweling would not normally be tested by this procedure and materials with a pronounced degree of curl would give erroneous results. Products with a bending resistance below 1.39 Gurley Units (or products not able to give a deflection between 1 and 7 on the scale when using the lightest weight) should not be tested by this procedure.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.