This test method describes the use of the M.I.T.-type folding apparatus for determining folding endurance of paper. The M.I.T. tester can be adjusted for papers of any thickness; however, if the outer fibrous layers of paper thicker than about 0.25 mm (0.01 in.) rupture during the first few folds, the test loses its significance. This test method is the technical equivalent of TAPPI T 511.

Formerly under the jurisdiction of Committee D06 on Paper and Paper Products, this test method was withdrawn in May 2010 because equivalent TAPPI and ISO publications exist.

The folding endurance of a paper is frequently used to estimate the ability of the paper to withstand repeated bending, folding, and creasing, and may be encountered as a measure of the quality of bank note paper, or document paper.

Folding endurance has also been found useful in measuring the deterioration of paper upon aging.

1.1 This test method describes the use of the M.I.T.-type folding apparatus for determining folding endurance of paper. The M.I.T. tester can be adjusted for papers of any thickness; however, if the outer fibrous layers of paper thicker than about 0.25 mm (0.01 in.) rupture during the first few folds, the test loses its significance. The procedure for the Schopper-type apparatus is given in Test Method D 643. This test method is the technical equivalent of TAPPI T 511.

1.2 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.