No abstract

In this study, far-infrared/anion-releasing elastic warp-knitted fabrics were successfully fabricated. Firstly, the composition and twist degree of ring-spun complex yarns that were made by rotor-twisting machine and ring-spinning frame were optimized based on twist contraction, hairiness, and tenacity measurements. The shell materials-1-ply bamboo charcoal (BC) roving, 1-ply phase change material (PCM) or the both (BC/PCM), and the core material-BC/stainless steel (BC/SS) wrap yarn, were formed into different compositions of ring-spun complex yarns. Afterward, elastic warp-knitted fabrics were fabricated using the optimized complex yarns as weft yarns, and rubber threads and polyester (PET) filaments as warp yarns. Air permeability, Downloaded from far-infrared emissivity, and anion amount of resulting warp-knitted fabrics were evaluated. Ring-spun complex yarn result shows that, twist contraction rate ratio increased, but hairiness decreased with increase of twist degree. Tenacity of ring-spun complex yarn made by BC roving (Type A) or PCM roving (Type B) first increased and then decreased with twist degree. However, when 1-ply BC and 1-ply PCM rovings were used as shell materials, the tenacity of resulting ring-spun complex yarn (Type C) decreased with twist degrees. Consequently, 12 twists per inch (T.P.I.) was the optimal twist degree for the following fabrication of warp-knitted fabrics. Air permeability, far-infrared emissivity, and anion amount of elastic warp-knitted fabrics composed of BC/SS wrap yarn and BC roving reached 44.35 cm 3 /s/cm 2 , 0.94e and 420 counts/cm 3 , respectively, indicating excellent breathability and far-infrared/anion-releasing health care functions.

Elastic warp-knitted composite fabrics with far-infrared emissivity and an anion-releasing property were prepared using bamboo charcoal (BC), copper (Cu), and phase-change material (PCM). The functional composite fabric, which was composed of self-made complex yarns with various twisting degrees and material composition, were created using a rotor twister and ring-spinning technique. The fabric structure was diversified by the feeding modes of weft yarn into a crochet-knitting machine. The twist number of complex yarns was optimized by tensile tenacity, twist contraction, and hairiness, and analysis showed that twisting at 12 twists per inch produced the highest tensile tenacity and appropriate twist contraction and hairiness. Comfort evaluation showed that the elastic composite fabrics with BC weft yarns exhibited higher water-vapor transmission rate and air permeability, reaching 876 g/m 2¨d ay and 73.2 cm 3 /s/cm 2 , respectively. Three structures of composite fabric with various weft yarns had >0.85 ε far-infrared emissivity and 350-420 counts/cm 3 anion amount. The prepared elastic warp-knitted fabrics can provide a comfortable, dry, and breathable environment to the wearer and can thus be applied as health-care textiles in the future.

This study proposes composite knits that have multiple functionalities to fit a diversity of applications. Stainless steel/rayon (S/R) wrapped yarns are used as the sheath and bamboo (B) charcoal polyester yarns are used as the core to form SRB wrapped yarns. The SRB wrapped yarns are made at number of twists of 2, 3, 4, 5, or 6 turns/cm. Moreover, the composite knits are made of SRB wrapped yarns as the face yarns and Tetoron® yarns as the ground yarns using a computer jacquard hose machine. The surface resistance, electromagnetic shielding effectiveness (EMSE), elastic recovery, anion release, and softness of the composite knits are measured, investigating the influence of the number of twists as well as the functionalities of the composite knits. When the number of twists is 4 turns/cm, the composite knits have an optimal elastic recovery of above 71.8%, optimal anion release of 408 counts/cm3, a greater softness along the wale direction, and optimal EMSE of 20 dB at frequencies of 2.18E+08 Hz.

Conventional sportswear fabrics are functional textiles that can mitigate the impaired muscles caused by exercises for the wearers, but they can also cause discomfort and skin allergy. This study proposes combining two yarns to form functional composite yarns, by using a twisting or wrapping process. Moreover, a different twist number is used in order to adjust the performance of functional composite yarns. A crochet machine is used to make the functional composite yarns into functional elastic knits that are suitable for use in sportswear. The test results show that, in comparison to the non-processed yarns, using the twisted or wrapped yarns can considerably decrease the water vapor transmission rate of functional elastic knits by 38%, while also improving their far infrared emissivity by 13%, water absorption rate by 39%, and air permeability by 136%. In particular, the functional elastic knits that are made of B-wrapped yarns (bamboo charcoal-wrapped yarns), composed of 20 twists per inch, have the optimal diverse functions.