Scott bond internal strength of paper or board

With this test, the energy required to rapidly delaminate a sheet-type specimen is measured. The z-directional rupture is initiated by the impact of a pendulum having both a controlled mass and a controlled velocity. The geometry of the apparatus causes the tensile stress to be rotational in nature with negligible shear stress on the specimen. The energy is absorbed during the elongation and stretching of the sample's fibre network prior to rupture, this test responds to the semi-elastic nature of paper and board. The test is a measurement of strain energy per unit sample area, which is proportional to the area under the stress-strain curve.