Reconciling Raw Flax Import Bales against Spun Yarn Output Yields
Reconciling raw flax imports against spun linen output relies on oven-dry mass adjustment, hackling yield tracking, and lot-specific transaction certificates.
Shive Content Measurement
Purity Test
Laboratory tests measure the quantity of residual woody stem fragments remaining in processed flax slivers or finished yarn. Conducting a shive content measurement provides a clear indication of how clean the flax fiber is before spinning. This test involves separating the non-fibrous woody pieces from the linen fiber bundle and calculating their dry weight ratio.
Process Control
Carding and combing machines must be adjusted to remove as many impurities as possible. A high shive content measurement indicates that the scutching and hackling stages were insufficient. This measurement helps operators optimize the draft settings on the drawframes to mechanically extract the remaining wood particles.
This control loop ensures the production of smooth, high-quality yarn.
Defect Limits
Buyers of high-grade linen yarn specify strict limits on the allowed impurities to avoid yarn breakage during high-speed weaving. When the shive content measurement exceeds the contractually allowed limit, the batch is rejected or downgraded to coarser applications. The laboratory documents this result on the quality control passport that accompanies the yarn shipment.
This documentation ensures that the fabric woven from this yarn will not suffer from excessive surface irregularities or dyeing faults. It also protects the mill from financial claims by demonstrating adherence to pre-agreed industrial standards.