Purging Procedure
Chemical extraction dissolves intercellular gums from bast fibres during preparation. Alkaline boiling baths eliminate plant pectins and residual lignins while targeting hemicellulose removal to expose pure cellulose before spinning mills draw the flax sliver. Sodium hydroxide solutions operating at high temperature hydrolyse these amorphous polysaccharides and wash away degradation products in large rinse tanks.
Mill technicians record residual mass loss percentage inside processing logs alongside bath concentration values.
Acceptance Criteria
Export inspection protocols govern linen yarn purity by measuring residual non-cellulose fractions after chemical treatments. Commercial buyers enforce strict tolerance limits for residual hemicellulose removal because excess pentosan chains retain ambient moisture and invite fungal growth during ocean transit. Laboratory technicians determine residual gum content through standard acid hydrolysis tests followed by gravimetric analysis of dried yarn samples.
Mill certificates declare compliance when measured polysaccharide fractions fall below designated contractual thresholds agreed upon prior to production.
Fibre Specification
Bast preparation grades distinguish between coarse technical fibres and refined spinning stock according to structural integrity standards. Processing logs separate raw flax classifications from finished yarn categories by tracking chemical purity milestones achieved throughout wet processing. Commercial supply contracts define exact boundaries where hemicellulose removal separates raw hackled flax from fine textile grade material destined for export looms.
Strict grading standards prevent excessive alkali exposure that degrades crystalline cellulose regions while ensuring adequate gum extraction for smooth yarn drafting.
