BS EN ISO 05089:2016 pdf download – Textiles — Preparation of laboratory test samples and test specimens for chemical testing (ISO 5089:1977)
ln the methods given in this International Standard, thelaboratory test samples are obtained by the combinationof numerous small portions each drawn from a differentpart of the laboratory bulk sample.Therefore, any resultsobtained on test specimens from these samples will estimatethe mean level in the laboratory bulk sample but will notindicate the variability of level from portion to portion ofthe laboratory bulk sample.Consequently it is appropriateto use this method in cases where it is desired to estimatethe bulk composition, for example the proportions ofdifferent fibres in a blend, but it is not appropriate in caseswhere variability is important, for example in thedetermination of pH where the local value is significant, orin the determination of fungicides,where a high value inone area of the material does not compensate for a lowvalue elsewhere. Nor may it be appropriate for use indetermination of commercial mass values.
This International Standard specifies methods of obtaininglaboratory test samples of textile materials from laboratorybulk samples taken from a bulk source, and gives generaldirections for the preparation of test specimens ofconvenient size for chemical tests.
No provision for sampling from the bulk source is describedsince it is assumed that the laboratory bulk sample has beenselected by a suitable procedure and is representative of thebulk source.
2.1bulk source : That quantity of material which is to bejudged on the basis of one series of test results.This maycomprise,for example, all the material in one delivery ofcloth; all the cloth woven from a particular beam; aconsignment of yarn; a bale or a group of bales of rawfibre.
2.2 laboratory bulk sample : That portion of the bulksource taken to be representative of the whole.The sizeand nature of the laboratory bulk sample should besufficient to overcome adequately the variability of thebulk source and to facilitate ease of handling in thelaboratory.
2.3 laboratory test sample : That portion of the laboratory bulk sample from which specimens are taken for testing. The size and nature of the laboratory test sample should be sufficient to overcome adequately the variability of the laboratory bulk sample.
2.4 test specimen: The portion of material required to give an individual test result.
The laboratory test sample is taken so that it is representative of the laboratory bulk sample. The test specimens are taken from the laboratory test sample in such a way that each of them is representative of the laboratory test sample.
4.1 Non-oriented fibres If the laboratory bulk sample consists of less than 5 kg of loose fibre, spread it out in an even layer. Obtain the laboratory test sample by taking at random a minimum of 100 tufts of approximately equal size, the total mass sufficient to give a laboratory test sample of required size. If the laboratory bulk sample is greater than 5 kg, divide it into a number of equal portions, and take an equal number of tufts of suitable mass from each portion such that the total number from all portions exceeds 100. Pretreat the laboratory test sample if required by the test method to be used. From the laboratory test sample remove at random, using forceps, small tufts of approximately equal mass to give a test specimen of the mass required.
4.2 Oriented fibres (card webs, slivers, rovings) From randomly selected parts of the laboratory bulk sample cut not less than ten crosssections each of mass approximately 1,0g. After applying pretreatment if necessary, lay the cross-sections together and obtain the test specimen by cutting through them so as to take a portion of each of the ten lengths.BS EN ISO 05089 pdf download.