ISO 4044:2017 pdf download – Leather — Chemical tests — Preparation of chemical test samples.
6 Preparation of test sample 6.1 Sample preparation Test pieces that are wet (i.e. in excess of approximately 30 % moisture) should be pre-dried at a temperature not exceeding 40 °C. The drying temperature should be selected with consideration of the influence of elevated temperature on the nature of the analyte. If the samples are dried at elevated temperature, they shall be conditioned according to ISO 2419. 6.2 Grinding This method of preparation shall be used when a sufficiently large piece of leather is available for grinding in a mill (5.1) to give a representative ground leather sample. As a guideline for the purpose of this document, the leather sample should be at least 200 mm × 200 mm or more than 10 g. Before grinding, the samples of leather should be reduced to small pieces of suitable dimensions depending on the design of the cutter mill feed system. It shall be ensured that the grinding mill and sample collecting device are clean. Water should not be used for cleaning. If sufficient sample is available, then a few small pieces of test leather should be ground and discarded, with the apparatus being cleaned again before proceeding with grinding the main test sample. 6.3 Cutting This method of preparation is used when only a small piece of leather is available. Typically this sample will be a part of a consumer item, for example a leather panel or piece from a leather product. For some leather test procedures it may be preferable to use test samples cut into pieces. The leather test samples are cut into small pieces using a suitable device with a sharp blade (5.2). The pieces shall be of 3 mm to 5 mm side length. 6.4 Choice of sample preparation method When the method for sample preparation is defined in a specific test method then the procedure specified shall be used. If no method of preparation is defined, then procedures specified in 6.2 and 6.3 are selected according to the size of the leather sample available. The method of preparation shall be reported in the test report.