EN ISO 4044:2017 pdf free download.Leather — Chemical tests — Preparation of chemical test samples.
ISO 4044:2017 specifies how to prepare a test sample of leather for chemical analysis. The test sample can be either ground or cut into small pieces. Unless specified in this document, the method to be used depends on the size of leather sample available for testing.
2 Normative references
ISO 2419, Leather-Physical and mechanical tests-Sample preparation and conditioning.
4 Principle
The leather sample shall be prepared by either:
— grinding in a mill to form”ground leather, see 5.1 and 6.2, or.
— cutting into small pieces, see 5. 2 and 6.3.
Which sample preparation shall be used depends on the size of the leather sample available or what preparation method is defined in the test method procedure.
5 Apparatus
5.1 Grinding milL, having a blade rotational frequency of 300 r/min to 1 000 r/min and a perforated sieving plate with (4,0 +0, 5) mm diameter perforations. The mill blades shall be sharp. To avoid samples heating up during grinding the preferred blade rotation should be towards the lower end of the rotational frequency range. Temperature shall not be higher than 40°C. Information about a suitable grinding mill is given in Annex A.
5.2 Suitable tool with a sharp blade for cutting leather samples into small pieces of 3 mm to 5 mm side length.
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.