BS EN ISO 8067:2018 pdf free
BS EN ISO 8067:2018 pdf free.Flexible cellular polymeric materials – Determination of tear strength
The tear strength shall be measured on a tensile-testing machine which will indicate the force at which rupture of the test piece takes place. An automatic machine should preferably be used which draws the actual curve, or a stylus or scale should be used having an indicator that remains at the point of maximum force after rupture of the test piece.The accuracy of the test machine shall be class 2 or better as defined in ISO 7500-1.
The test pieces shall be free of voids and flow lines. Test pieces can be selected either with or without skin. If the material exhibits a predominant direction of cellular structure (orientation of the cells), the trouser test piece shall be taken in such a way that the plane of the cut subsequently made in the test piece (see Figure 1) is parallel to, and the long dimension of the cut perpendicular to, the predominant foam-rise direction and the angle test piece shall be taken in such a way that the plane of the V-shaped side of the test piece (see Figure 3) is parallel to, and the long dimension of the test piece perpendicular to, the predominant foam-rise direction. If this is not possible, the orientation of the long dimension of the cut or the V-shaped side of the test piece with respect to the predominant foam-rise direction shall be stated in the test report. See Annex A for the difference of test results and the precision for each type of test pieces.
The trouser test piece shall be a rectangular parallelepiped cut from a sheet of material with a band knife or a cutting die. Each test piece shall have the dimensions given in Figure 1 and a 45 mm to 55 mm cut shall be made at one end. The required tear length (25 mm) shall be marked on the test piece. The predominant foam-rise direction for the trouser test piece is indicated by an arrow in Figure 1.BS EN ISO 8067 pdf free download.
