Refinement Stage
Refinement stage where the glue-like substances that hold flax fibres together are removed through heat and chemical agents. Non-cellulosic pectin dissolution involves the transition of solid pectin into a soluble state within a scouring liquor. Chemical processing refines the raw flax bundles into finer strands suitable for high-quality weaving.
Chemical Environment
Alkaline solutions are typically used in the mill to facilitate this dissolution. The presence of sodium hydroxide at high temperatures breaks the ester bonds in the pectin molecules. This chemical action is assisted by sequestering agents that remove calcium ions, which otherwise stabilize the pectin structure.
Non-cellulosic pectin dissolution occurs most efficiently when the pH of the bath is maintained above ten. Progress is monitored by measuring the weight loss of the fibre samples and the clarity of the treatment liquor.
Fibre Modification
Success of this process determines the final handle and dye affinity of the linen fabric. Removing these pectins opens up the internal structure of the fibre, allowing for better penetration of dyes and finishes. If the non-cellulosic pectin dissolution is uneven, the fabric will show blotchy color and inconsistent shrinkage.
However, the process must stop before the primary cell walls are weakened. Laboratory analysis of the residual pectin content ensures that the fibres retain enough structure to survive the weaving process.
