ISO 5270:2012 pdf download – Pulps — Laboratory sheets — Determination of physical properties.
5.3 Optical properties For certain purposes, it may be desirable to measure optical properties of laboratory sheets prepared using the conventional sheet former (ISO 5269-1 or ISO 5269-3). Depending on the purpose, light scattering and light absorption coeffcients, opacity, ISO brightness and CIE whiteness can be measured. Optical properties for sheets prepared using the conventional sheet former (ISO 5269-1, ISO 5269-3) should be tested without pre-conditioning and no optical tests should be performed on sheets prepared using the Rapid-Köthen sheet former (ISO 5269-2, ISO 5269-3). NOTE 1 Preparation of laboratory sheets for the measurement of diffuse blue refectance factor (ISO brightness) of pulp is specifed in ISO 3688 [2] . The sheets having a grammage of 200 g/m 2 are prepared in a sheet former (ISO 5269) or in a Büchner funnel. The measurement of ISO brightness is described in ISO 2470-1 [3] . NOTE 2 For the determination of light scattering and light absorption coeffcients of the low-grammage laboratory sheets ISO 9416 [4] is recommended, and for the determination of opacity ISO 2471 [5] is recommended. NOTE 3 For the determination of CIE whiteness, it is recommended to use either ISO 14475 [6] or ISO 14476 [7] . 5.4 Determination of grammage, bulking thickness and apparent bulk density Trim the laboratory sheets, using a punch, or a ruler and a pair of scissors, to obtain a defned size so that the area can be determined to an accuracy of 0,5 %. For “low grammage” sheets, consult Table 1 in 5.5 to establish a suitable size for the trimmed sheets that allows them to be used for cutting test pieces. Before cutting test pieces, determine the grammage of the conditioned trimmed sheets using ISO 536. The mass of the trimmed sheets shall be determined to an accuracy of 0,2 % and the grammage shall be reported to three signifcant fgures. NOTE If a circular sheet having a diameter of 158 mm is used, only two test pieces for the determination of fat crush resistance or ring crush resistance can be cut from each she