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- Practical Guide -
Page 115 of 153
The colouring matter (M%) is also measured in the conditioned specimens. If inorganic
pigments are identified, incineration enables the gravimetric determination. If soluble dyes are
present, a spectrophotometric analysis is a suitable.
Corrections to be made on the percentages of cellulose (=C%), softeners (=S%) and
other additives (=A%)
C% (corrected value) = C% x 100/(100-W-L-M)
S% (corrected value) = S% x 100/(100-W-L-M)
A% (corrected value) = A% x 100/(100-W-L-M)
Nota bene
The minimum cellulose content in the anhydrous RCF has been fixed at 72 % (Council Directive 83/229/EEC).
This value refers to the anhydrous, uncoated RCF and it does not take into account the colouring matters.