IS 6504 : 1979 Method for quantitative chemical analysis of ternary mixtures of viscose rayon, cotton and protein fibres

1 Scope

1.1 This standard prescribes a method for quantitative chemical analysis ofternary mixtures of:

a) viscose rayon, undyed and dyed (including most of the current polynosicfibres);

b) cotton, undyed and dyed; and

c) protein fibres, undyed and dyed.

1.1.1 If a polynosic fibre is found to be present, a preliminary test shouldbe carried out to see whether it is soluble in the reagent. If several proteinfibres are present, the method gives the total of their amounts, but not theirindividual quantities.

NOTE - Before conducting an analysis according to this, method, the fibrespresent in the mixture should be identified (see IS 667 : 1955) and sample to beanalyzed shall be freed from all non-fibrous matter. Dye in the dyed fibres isconsidered to be an integral part of the fibre and is not to be removed.

1.2 This method is not suitable to mixtures in which cotton or viscose rayonhave suffered extensive chemical degradation, nor when the viscose rayon isrendered incompletely soluble by presence of certain permanent finishes orreactive dyes that cannot be removed completely.

2 References

IS 2 :1960 Rules for rounding off numericalvalues

IS 667 :1955 Simple methods for identification of commoncommercialtextile fibres

IS 1070 :1977 Specification for water for general laboratory use

IS 9068 :1979 Recommended methods for the removal of non-fibrousmatter prior to quantitative analysis of fibre mixtures