BS 1762 pdf free download

BS 1762-2019 pdf free download.Paper, board, pulps and cellulose nanomaterials — Determination of residue (ash content) on ignition at 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 ± 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.
5.4 Desiccator.
6 Sampling and preparation of test specimen WARNING — The method specified in this document involves the use of nanomaterials. Care should be taken to ensure observation of the relevant precautions and guidelines for nanotechnology laboratory safety and best practices.
6.1 Sample amount Sufficient material shall be collected to allow for at least duplicate determinations and for determination of moisture or dry matter content.
6.2 Paper, board and pulp sampling Guidance on obtaining representative samples found in ISO 186 for paper and board and in ISO 7213 for pulps delivered in bales or rolls shall be followed in cases where the analysis is being conducted to evaluate a lot. In this case or if the tests are made on another type of sample, take test specimens from various parts of the sample making sure they are thoroughly representative of the sample. The test specimen taken for incineration shall consist of a number of small pieces no larger than 1 cm 2 . In a similar manner, obtain a moisture content or dry matter content specimen from the sample. The specimen for incineration shall have a total mass of not less than 1 g on an oven-dry basis, and sufficient to give a residue on ignition of not less than 10 mg and preferably over 20 mg (see Clause 7). If the material has a very low residue on ignition (for example, in the case of so-called ashless grades), it might be necessary to divide the test specimen into two or several smaller portions which are incinerated consecutively in the same crucible, in order to obtain a total residue of at least 10 mg.
6.3 Cellulose nanomaterial sampling For cellulose nanomaterials, care should be taken that the procedure is appropriate for the material being sampled. There is no ISO standard procedure for sampling cellulose nanocrystals, either in aqueous suspensions or dried forms, or for sampling dilute (wet) cellulose nanofibrils. When the original cellulose nanomaterial sample is a wet form or an aqueous suspension (dilute or concentrated), it shall be dried using an appropriate method such as heating at 105 °C, freeze-drying or spray-drying, to give the sample in a solid form such as flakes, powder or other solid, which shall be mixed to homogeneity. The test specimen shall be obtained from this pre-dried sample. In a similar manner, obtain a moisture content or dry matter content specimen from the sample. Filtration to concentrate dilute samples prior to drying is not recommended as it may result in loss of dissolved material which gives ash upon heating to 525 °C.BS 1762 pdf download.