Standard Test Method for Tensile Strength at Zero-Span ("Wet Zero-Span Tensile")
|Publication Date:||10 December 1997|
|ICS Code (Mechanical testing):||19.060|
1.1 This test method provides a quick, reliable means to measure the wet zero-span tensile strength of a specimen of sheeted material.
1.2 In cases where fibers are to be tested prior to finished production of paper or paperboard, a random standard aggregate of pulp fibers, or handsheet, produced using a standardized procedure, such as, TAPPI T 205 is required.
1.3 This test method requires specimens such as those described in 1.2.
1.4 While testing is possible on finished paper or paper-board, information on fiber quality from intermediate steps in the pulping or papermaking process, or both, is frequently more useful for improving finished paper and paperboard quality or improving fiber utilization of recycled fibers, or fibers subjected to new pulping, bleaching, or finishing processes (1, 2, 3, 4).
1.5 The modifications of this test method required for testing finished paper is straightforward; however, testing shall be done in the two principle directions of the sheet, as required in Test Method D 829. The finished paper or paperboard will generally have nonrandom fiber orientation, resulting in different strength properties in the two principle directions of the finished sheet. Testing of sheets having a grammage greater than 100 g/m2, which includes some paper materials described as paper and many paperboards, is difficult because of problems associated with clamping of individual fibers as the number of fibers per unit area increases.
1.6 Modifications such as those in 1.5 are not described in this test method. If modifications are made, they must be acknowledged and clearly described in the report as deviations from the standard procedure.
1.7 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.