Structural Bonding
The adhesive strength of the intercellular pectin layer that binds individual flax fibres together into composite bundles governs the behavior of the material during chemical and mechanical processing. Proper management of middle lamella cohesion is necessary to allow the splitting of coarse bundles into fine spinable fibres without causing complete disintegration of the fibre structure. This bonding is partially broken down during the retting process to prepare the flax for scutching and hackling.
Chemical Treatment
In wet spinning, the remaining pectins must be softened in hot water to allow the fibres to slide past one another during the drafting stage. If the middle lamella cohesion is too high, the drafting rollers cannot separate the fibres, which causes thick places and heavy ends in the yarn. Conversely, if the chemical treatment has been too aggressive, the pectins are completely dissolved, which leads to weak strands and high breakage rates.
Spinning mills use controlled temperatures and mild alkaline solutions in the spinning trough to achieve the correct level of softening.
Fabric Performance
The residual bonding between the fibres determines the durability and surface character of the finished linen cloth. Retaining a controlled amount of cohesion prevents the yarn from linting during subsequent washing and wearing.
