BS ISO 1762:2019 pdf free.Paper, board, pulps and cellulose nanomaterials – Determination of residue (ash content) on ignition at 525 °C.
4 Principle The test specimen is weighed in a heat-resistant crucible and ignited in a muffle furnace at 525 °C+ 25 °C. The moisture or dry matter content of a separate test specimen is also measured. The percentage ash is then determined, on a dry (moisture-free) basis, from the mass of residue after ignition and the moisture or dry matter content of the sample. The ash may consist of a] mineral matter in the paper, board, pulp and cellulose nanomaterial and various residues from chemicals used in its manufacture; b] metallic matter from piping and machinery; c] fillers, pigments, coatings or residues from various additives. In samples containing calcium carbonate, there is practically no decomposition of carbonate by ashing at 525 °C. Other fillers and pigments such as clay and titanium dioxide are also unaffected by ashing at 525 °C. Accordingly, the residue on ignition provides a good estimate of the total inorganic matter in the sample, provided that the sample does not contain other minerals which decompose at or below this temperature. For example, magnesium carbonate and calcium sulfate may, at least partly, decompose at temperatures below 525 °C. 5 Apparatus 5.1 Heat-resistant crucibles, made of platinum, porcelain or silica, with a capacity of 50 ml to 100 ml. Larger-capacity crucibles may also be used for low-density materials to accommodate sufficient sample. A lid of an appropriate material, placed slightly ajar to allow air for combustion, may also be used with the crucible to help prevent low density or flyaway material from escaping during the ash ignition process. Platinum crucibles are recommended if a small amount of residue is expected. 5.2 Muffle furnace, capable of maintaining a temperature of 525 °C士25 °C. It is recommended that the furnace be placed in a hood or that means are provided for evacuating smoke and fumes. 5.3 Analytical balance, with a scale division (readability) of 0,1 mg or better in order to obtain a measurement precision of 0,01 % or better.BS ISO 1762 pdf download.