Raw Parenchyma
Harvested flax phloem tissues contain intact pectinaceous middle lamellae holding cortical fiber bundles firmly against woody inner stems. Raw plant material is identified as unretted bast when decortication occurs without prior biological stem degradation. This unretted condition presents high mechanical resistance to fiber separation during scutching.
Processing raw unrotted straw requires aggressive mechanical decortication rather than standard scutching line extraction.
Chemical Digestion
Intact plant stems harvested directly after seed maturity carry high concentrations of insoluble calcium pectate binding fiber bundles to cortical parenchyma cells. Without fungal or bacterial enzymatic breakdown, mechanical scutching blades fail to detach clean fibers, causing heavy stem shattering and producing short, coarse fiber bundles contaminated with attached shive fragments. Chemical extraction plants purchase raw unretted straw for enzymatic or alkaline boiling processes in pressurized tanks, bypassing field retting entirely.
Chemical retting dissolves middle lamellae rapidly under controlled temperature and pH conditions, yielding highly uniform technical fibers with consistent residual wax levels. Laboratory tests determine residual pectin content to calculate chemical liquor concentrations required for thorough fiber separation.
Straw Intake
Raw straw purchasing specifications record stem moisture and shive adhesion forces before factory delivery. Material failing decortication tests undergoes hot alkaline digestion. Raw fiber classification ceases once chemical boiling dissolves inter-cellular pectins and releases isolated fiber bundles.
