Numerical simulation and analysis of airflow in the condensing zone of compact-siro spinning

Abstract

Compact-siro spinning is a new kind of spinning technique that combines compact spinning and siro spinning, and is widely put into practice. In this paper, a simulation and characterization of the flow field in the condensing zone are made by computational fluid dynamics software. It mainly includes the distribution rules of static pressure and velocity. According to the relative references and factory condition, several orthogonal and control experiments have been done. Through testing the strength, evenness and hairiness properties and analyzing and comparing the results with the data of three different suction slots, we select the compact-siro spinning suction device whose yarn has the best overall performance. The theory analysis gives foundation and explanation for the experiment, and also provides a theoretical basis for optimizing the properties of compact-siro yarn in production practice.Compact-siro spinning 1 is a new kind of spinning technique that combines compact spinning 2 and siro spinning, 3 and is widely put into practice. Siro spinning parallelly feeds two rovings with a certain pitch into the same drafting zone of the spinning frame. Then the two rovings are twisted on one spindle after the draft parallelly. The structure of siro spun yarn is similar to plied yarn, with good strength, hairiness 4 and evenness properties. However, it has disadvantage of worse twist stability and indistinctive plied yarn characteristic. As previous research shows, the compact spinning system 5 can decrease the twisting triangle zone and make the fiber tangled. Therefore, considering the advantage of the two spinning techniques, compactsiro spinning can give the yarn a stable and obvious twisting structure under negative pressure. 6 Yang 7 studied an advanced spinning technology that combined compact spinning and siro-spinning in a traditional ring spinning machine. Wang 8 studied the spinning mechanism and the yarn structure of compact-siro spinning. Wang 9 made a systematic analysis for the causes of the increase in compact-siro spun yarn strength, evenness and the decrease in hairiness in theory. Lu 10 studied influences of airflow on fiber movement on compact-siro spinning with a lattice apron. If the technique is mature enough, it will result in savings in cost, energy and labor force, leading to better market prospects. In this paper, the numerical simulation of airflow in the condensing zone of compact-siro spinning is studied, and the impact factors of the agglomeration effects are analyzed. The comprehensive performances of three different suction slots are compared, and the compact-siro spinning suction device whose yarn has the best overall performance is selected.

Numerical Simulation of the Condensing Effect of Different Suction Slots on Fiber Strands in a Compact Siro Spinning Machine with Lattice Apron

“…The ranges of the axes are set as follows: X-axis [0, 19]; Y-axis [-6, 12], and Z-axis [0, 3] in REGION [12]. As shown in Figure 3(b), the faces 1, 2, 3, 4, and 5 are specified as the pressure entrance faces, the face in the negative pressure area of the shaped tube is specified as the pressure exit face, and the others are specified as the wall [13]. The pressure entrance is at an atmosphere condition, and the exit is in a negative pressure (P=2.35 kPa).…”

Büküm İplikçiliği (Siro-Spun) Teknolojisindeki Gelişmeler ve Hibrit Eğirme Teknolojileri

“…Çıkış silindirleri sonuna eklenen farklı yüzeydeki yapılar a) geleneksel eğirme sistemi b) düz yüzeyde kuru eğirme c) düz yüzeyde ıslak eğirme d) kuru yüzeyde ıslak eğirme e) yivli yüzeyde ıslak eğirme [40] Şekil 10. Kompakt-siro çekim bölgesine ilave edilen hava kanallı yapı [41].…”

Three-dimensional simulation and experimental investigation of three-dimensional printed guiding devices on lattice-apron compact spinning

“…Their works concluded that the flow field distribution largely depends on the roller lattice-apron type and subsequently affects the yarn properties in the condensing zone. Han et al 25,26 studied the condensing effects of different suction slots, where parallel-shaped slots, oblique parallel-shaped slots, and V-shaped slots were studied. The fiber trajectory and flow field in the condensing zone were simulated and characterized in a compact Siro spinning machine with a lattice apron.…”