Paper tensile energy absorption

Folding endurance under tension (10) is a favorite physical property for research on paper permanence and is the basis for the TAPPI method (16). Application of the mechanism involved in this test procedure, however, is unknown in practical uses for paper. Comparisons among product choices and estimates of their useful life should be based upon tests that assess physical properties of practical interest. Retention of reflective brightness, tear strength, tensile energy absorption, and... 

Tear and tensile energy absorption usually increased, and these properties are important to the handling properties of paper. 

In this case, the paper machine manufactures flat sack kraft paper from a blend of virgin pine (long-fibre) kraft pulp with typical Kappa range of 55-65 and eucalyptus (short-fibre) neutral sulfite semi-chemical (NSSC) pulp. The most important properties for sack papers are stretch and tensile energy absorption (TEA) in both cross direction (CD) and machine direction (MD). The major problems with the quality of sack papers currently made on this machine were poor stretch and TEA profile in fhe cross direction as shown in... 

Not only the strength properties, tensile strength and strain to rupture can be determined in the tensile strength test (ISO 1924, 1992), but also the tensile energy absorption, TEA, which is especially important for bag paper. The TEA value represents the nonelastic portion of the deformation energy and thus that portion of dissipated energy which should be high in the case of bag paper. 

Since the environmental history of the book would influence the results obtained from physical property measurements made on the paper, each book was preconditioned in a standard atmosphere (4) before any paper samples were removed. The following physical property measurements were made on the same pages throughout each of the control and dried books tensile breaking strength (5) tensile energy of absorption (6, 7) internal tear resistance (8) thickness (9) and hot-water extract-able acidity or alkalinity (10). 

Metals in pulps and papers were determined after wet-ashing with nitric acid by atomic absorption techniques using a commercial instrument. Tensile properties (load at break, elongation at break, energy to break) were determined using a commercial recording load-elongation machine (45),... 

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