Division I.8.2 - Regulation (EU) No 1007/2011 of the European Parliament and of the Council of 27 September 2011 on textile fibre names and related labelling and marking of the fibre composition of textile products and repealing Council Directive 73/44/EEC and Directives 96/73/EC and 2008/121/EC of the European Parliament and of the Council (Text with EEA relevance)

Calculation of the percentage of each component with adjustment by agreed allowances and, where appropriate, correction factors for losses in mass during pre-treatment operations:

Given:

$A = 1 + \frac{a_{1} + b_{1}}{100}$ $B = 1 + \frac{a_{2} + b_{2}}{100}$ $C = 1 + \frac{a_{3} + b_{3}}{100}$

then:

P₁A%

is the percentage of the first clean dry component, including moisture content and loss in mass during pre-treatment,

P₂A%

is the percentage of the second clean dry component, including moisture content and loss in mass during pre-treatment,

P₃A%

is the percentage of the third clean dry component, including moisture content and loss in mass during pre-treatment,

P₁

is the percentage of the first clean dry component obtained by one of the formulae given in I.8.1,

P₂

is the percentage of the second clean dry component obtained by one of the formulae given in I.8.1,

P₃

is the percentage of the third clean dry component obtained by one of the formulae given in I.8.1,

a₁

is the agreed allowance of the first component,

a₂

is the agreed allowance of the second component,

a₃

is the agreed allowance of the third component,

b₁

is the percentage of loss in mass of the first component during pre-treatment,

b₂

is the percentage of loss in mass of the second component during pre-treatment,

b₃

is the percentage of loss in mass of the third component during pre-treatment.

Where a special pre-treatment is used the values b₁, b₂ and b₃ shall be determined, if possible, by submitting each of the pure fibre constituents to the pre-treatment applied in the analysis. Pure fibres are those free from all non-fibrous material except those which they normally contain (either naturally or because of the manufacturing process), in the state (unbleached, bleached) in which they are found in the material to be analysed.

Where no clean separate constituent fibres used in the manufacture of the material to be analysed are available, average values of b₁, b₂ and b₃ as obtained from tests performed on clean fibres similar to those in the mixture under examination, must be used.

If normal pre-treatment by extraction with light petroleum and water is applied, correction factors b₁, b₂ and b₃ may generally be ignored, except in the case of unbleached cotton, unbleached flax (or linen) and unbleached hemp where the loss due to pre-treatment is usually accepted as 4 % and in the case of polypropylene as 1 %.

In the case of other fibres, losses due to pre-treatment are usually disregarded in calculations.