BS 4407:1988 pdf download.Quantitative analysis of fibre mixtures.
3 Apparatus
3.1 Glass-filter crucibles, with sealed-in sintered disc filters of porosity grade P160 complying with BS 1752 and provided with either ground-glass stoppers or watch glass covers.
3.2 Soxhlet extractor, complying with BS 2071.
3.3 Weighing bottles.
3.4 Ventilated oven for drying specimens at 105 ± 3 °C.
3.5 Desiccator containing self-indicating silica gel. 3.6 Analytical balance, accurate to ± 0.0002 g. 3.7 Vacuum flask.
3.8 Additional apparatus as specified in the appropriate clauses of this standard.
4 Reagents
4.1 Light petroleum, redistilled, boiling range 40 °C to 60 °C.
4.2 Water complying with grade 3 of BS 3978.
4.3 Other reagents as specified in the appropriate clauses of this standard.
5 Conditioning and testing atmosphere Dry masses are determined and therefore it is unnecessary to condition the specimen. The analysis is carried out under ordinary room conditions.
6 Sample Take a sample that is representative of the bulk and sufficient to provide all the specimens, each of at least 1 g, that are required. Follow the sampling procedure as described in BS 4658.
7 Pretreatment of sample Extract the air-dry sample in a soxhlet apparatus (3.2) with light petroleum for 1 h at a minimum rate of 6 cycles/hour. Allow the light petroleum (4.1) to evaporate from the sample. Then extract it by immersing the sample in water at room temperature for 1 h and then immersing it in water at 65 ± 5 °C for a further hour, agitating the liquor from time to time. Use a liquor to sample ratio of 100 : 1.
Where non-fibrous matter, e.g. size or special finish, cannot be extracted with light petroleum and water, remove it by substituting for the water treatment described above, a suitable method that does not substantially alter any of the fibre constituents. However, for some unbleached, natural vegetable fibres (e.g. jute, coir) note that normal pretreatment with light petroleum and water does not remove all the natural non-fibrous substances. Do not apply additional pretreatment unless the sample does contain finishes insoluble in both light petroleum and water. Include full details of the methods of pretreatment used in the analysis report.
8 Test procedure
8.1 General instructions 8.1.1 Drying. Conduct all drying operations for not less than 4 h and not more than 16 h at 105 ± 3 °C in a ventilated oven with the oven door closed throughout. If the drying period is less than 14 h, weigh the specimen or residue to check that its mass has become constant. The mass may be considered to have become constant if, after a further drying of 60 min, its variation is less than 0.05 %. Where apparatus other than a filter crucible is used, conduct drying operations in the oven in such a way as to enable the dry mass of the fibres to be determined without loss of fibre.
BS 4407 pdf download.