1.1 This standard prescribes a method for quantitative chemical analysis of ternary mixtures of:
a) viscose rayon, undyed and dyed (including most of the current polynosic fibres);
b) cotton, undyed and dyed; and
c) protein fibres, undyed and dyed.
1.1.1 If a polynosic fibre is found to be prcesent, a preliminary test should be carried out to see whether it is soluble in the reagent. If several protein fibres are present, the method gives the total of their amounts, but not their individual quantities.
Note — Before conducting an analysis according to this method, the fibres present in the mixture should be identified ( see IS : 667-1955* ) and sample to be analyzed shall be freed from all non-fibrous matter. Dye in the dyed fibres is considered 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 rayon have suffered extensive chemical degradation, nor when the viscose rayon is rendered incompletely soluble by presence of certain permanent finishes or reactive dyes that cannot be removed completely.
1.1.1 If a polynosic fibre is found to be prcesent, a preliminary test should be carried out to see whether it is soluble in the reagent. If several protein fibres are present, the method gives the total of their amounts, but not their individual quantities.
Note — Before conducting an analysis according to this method, the fibres present in the mixture should be identified ( see IS : 667-1955* ) and sample to be analyzed shall be freed from all non-fibrous matter. Dye in the dyed fibres is considered 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 rayon have suffered extensive chemical degradation, nor when the viscose rayon is rendered incompletely soluble by presence of certain permanent finishes or reactive dyes that cannot be removed completely.
IS 6504-1979 history
1979IS 6504-1979 Methods for quantitative chemical analysis of ternary mixtures of viscose rayon, cotton and protein fibers