Hackling Yield and Wet-Spinning End Breakage in Blended Bast Bales
Optimizing hackling pin density and wet-spinning trough temperature stabilizes draft forces, reducing bast yarn end breakage below fifteen breaks per thousand spindle hours.
Roving Preparation
Preliminary Processing
Intermediate sliver attenuation converts combed or drawn flax slivers into lightly twisted, manageable packages suitable for ring frame creels. Spinning preparatory departments implement roving preparation across Chinese wet linen mills to deliver uniform linear mass reduction while inserting protective twist. This transitional stage groups drawing frame slivers, attenuates them through multi-roller drafting zones, and winds the resulting strand onto wooden or perforated bobbins via revolving flyer mechanisms.
The boundary of this manufacturing stage terminates at the roving frame doffing rail before bobbins transfer into the wet spinning room creels. Production supervisors register sliver input weight and roving hank output on the roving production ledger.
Twist Insertion
Rotating flyers impart protective twist into the drafted fiber bundle, conferring sufficient tensile strength to allow uncoiling in spinning creels without premature breakage. Flax fibers possess flat, smooth surface walls lacking natural crimp, which necessitates exact flyer speed synchronization to prevent catastrophic bundle slippage during winding. Perforated plastic or stainless steel roving bobbins allow warm water to penetrate through wound roving layers during subsequent wet spinning soaking treatments.
If insufficient twist is inserted during roving preparation, the soft strand pulls apart during creel unwinding and halts the spinning frame spindle. Excessive roving twist blocks fiber displacement within downstream drafting zones, creating slubs and core breaks. Technicians measure roving linear density by weighing precise reel lengths on certified laboratory balances.
Spinning Feed Control
Mill processing manuals specify roving twist multipliers and hank tolerances to guarantee uniform drafting behavior, whereas yarn buyers verify final yarn count consistency and single-end breaking strength on finished linen cones. Preparatory workers inspect roving packages for uneven winding density, sloughed coils and broken ends before sending carriers to the ring spinning hall. When roving packages exhibit variable cross-sectional thickness, wet spinning frames produce cyclical thin spots that fail downstream electronic yarn clearers.
Testing technicians enter mass variation profiles and twist per meter measurements into the preparatory shift report before staging material for spinning. Uniform roving package construction guarantees continuous ring frame operation across high-count linen production cycles.