# Fineness of fibres

Fineness of fibres in general indicates the relation between length and weigth or conversely.

What results are basically two different systems for numeration:

#### 1. Numeration of length

The notation of fineness of fibres, yarns and twisted yarns happens according to length of a certain weight of a fibre, yarn or twisted yarn. The calculation is refered to as numeration of length or shortly numeration. Notation of fineness is made as number, symbol N.

N = length ÷ weigth unit

We differentiate into metrical [Nm], english [Ne] und french number [Nf]

 Definition: Indicates Numeration Nm Ne Nf how many metres of yarn weigth = 1 g x Nm = 1 Nm x 0,591 Nm x 0,5 how many skeins of 840 yards length weigth = 1 lb (= 453,6g) x Ne = Ne x 1,693 1 Ne x 0,847 how many skeins of 1000m length weight = 500g x Nf = Nf x 2 Nf x 1,18 1

In general:

• The finer a fibre, a yarn or a twisted yarn, the higher is the number.
• It is mainly used in case of staple fibres.

#### 2. Numeration of weigth

The notation of fineness of fibres, yarns and twisted yarns happens according to weigth of a certain length of a fibre, yarn or twisted yarn. The calculation is refered to as numeration of weigth or shortly titration. Notation of fineness is made as titer, symbol T.

N = weigth ÷ length

In general:

• The finer a fibre, a yarn or a twisted yarn, the lower is the titer.
• If the substance or the fibre mass of the profile or the length unit gets lower, the titer also gets lower and reverse.
• It is mainly used in case of filaments.
 Definition: Indicates Titer Tden Tex Nm how many grams weigth 9000m of the yarn x Tden = denier 1 Tden x 0,11111 9000 Tden how many grams weigth 1000m of the yarn x Tex = Tex  x  9 1 1000  Tex how many grams weigth = 1 g x  Nm = 9000 Nm 1000 Nm 1

Other units: dtex = Tex x 10

Source: Ciba Umrechnungstabellen

### Microfibres

Microfibres are PES or PA-fibres with very low titers, that are in the order of below 1dtex.

Specification: dtex 100 F144 = yarn strength 100 dtex and numer of fibrils F = 144

If the number of fibrils is greater than the yarn number, the fibre is described as micro fine.

If the number of fibrils is lower than the dtex number we can talk about a fine but not micro fine fibre.

Examples:

dtex 76 F144 = 76 ÷ 144 = 0,5 dtex = Micro fibre

dtex 76 F24   = 76 ÷ 24  = 3,2 dtex = Normal fibre

Attention: Microfibres are to be treated differently in dyeworks due to the distinctly greater surface.

Source: Sandoz Mikrofasern