Semi-open-end twisting mechanism of fiber strand in condensing zone in pneumatic compact spinning with lattice apron

The spinning process of pneumatic compact spinning with lattice apron indicates that under the same spinning condition,the twist of the compact spun yarn is about 5% higher than that of the ring spun yarn when the yarns have the same linear density.In order to reveal the formation mechanism of this phenomenon,the high-speed camera was used to capture the condensing process of the fiber strand in the condensing zone with linear suction slot.The existence of the phenomenon similar to a wrap twisting was observed.Spinning experiments of the two processes were performed,and the twist of the compact spun yarn and ring spun yarn,produced under the same condition and having the same linear density,were compared.The additional twists in the fiber strand in the condensing zone,which were considered to be real twists,were also confirmed.Based on these results,a semi-open-end twist model was proposed to explain the formation mechanism of the additional twists in the fiber strand in the condensing zone of the pneumatic compact spinning.