Scutching and heckling
The long and short flax fibres are separated in a purely mechanical process.
First, the woody core of the flax plant’s stem is broken by heavy, counterrotating toothed rollers. During retting, the material connecting the woody and fibrous bast parts was dissolved so much that they can now be separated from each other during this breaking process.
The pieces of broken wood are discarded during the scutching step.
In the past, this step was done by hand using wide wooden knives. Today, it is carried out by machines with modern turbines. Only long flax fibres remain after scutching.
The last step in flax processing is heckling. It splits the flax fibres and the fibrous bast.
Afterwards, the approximately 60-to-100cm-long fibre bundles are sorted by hand and formed into bales.
Depending on the colour, purity, length and uniformity of the fibres, they are categorised into premium quality, slightly defective and inferior quality.
The long fibres are stored by batch and delivered to spinning mills.
About 14 to 21% of flax straw are long fibres.