This study proposes melt-blending polypropylene (PP) and high density polyethylene (HDPE) that have a similar melt flow index (MFI) to form PP/HDPE polyblends. The influence of the content of HDPE on the properties and compatibility of polyblends is examined by using a tensile test, flexural test, Izod impact test, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), polarized light microscopy (PLM), and X-ray diffraction (XRD). The SEM results show that PP and HDPE are incompatible polymers with PP being a continuous phase and HDPE being a dispersed phase. The FTIR results show that the combination of HDPE does not influence the chemical structure of PP, indicating that the polyblends are made of a physical blending. The DSC and XRD results show that PP and HDPE are not compatible, and the combination of HDPE is not correlated with the crystalline structure and stability of PP. The PLM results show that the combination of HDPE causes stacking and incompatibility between HDPE and PP spherulites, and PP thus has incomplete spherulite morphology and a smaller spherulite size. However, according to mechanical property test results, the combination of HDPE improves the impact strength of PP.

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/m²∙ day and 73.2 cm³/s/cm², respectively. Three structures of composite fabric with various weft yarns had >0.85 ε far-infrared emissivity and 350–420 counts/cm³ 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.

The recycled Kevlar^®/polyester/low-melting-point polyester (recycled Kevlar^®/PET/LPET) nonwoven geotextiles are immersed in neutral, strong acid, and strong alkali solutions, respectively, at different temperatures for four months. Their tensile strength is then tested according to various immersion periods at various temperatures, in order to determine their durability to chemicals. For the purpose of analyzing the possible factors that influence mechanical properties of geotextiles under diverse environmental conditions, the experimental results and statistical analyses are incorporated in this study. Therefore, influences of the content of recycled Kevlar^® fibers, implementation of thermal treatment, and immersion periods on the tensile strength of recycled Kevlar^®/PET/LPET nonwoven geotextiles are examined, after which their influential levels are statistically determined by performing multiple regression analyses. According to the results, the tensile strength of nonwoven geotextiles can be enhanced by adding recycled Kevlar^® fibers and thermal treatment.

Environmental protection has become an increasing concern, which makes recycling and reclaiming highly important. In addition to governmental campaigns and promotion, enterprises should examine each perspective thoroughly in order to prevent excessive resource consumption. In this study, recycled materials, including recycled far-infrared polyester (FPET) fiber, three-dimensional crimped hollow flame-retarding (TPET) fiber, and low-melting-point polyester (LPET) fiber, are used to form nonwoven fabrics. The influence of different amounts of FPET fiber, 0–80 wt %, on the properties of nonwoven fabrics was examined. The sheath of LPET fibers can be melted as a result of hot pressing, which provides cohesion between fibers that mechanically improves the nonwoven fabrics. The tensile strength, tearing strength, air permeability, and far infrared (FIR) emissivity of the nonwoven fabrics were examined, thereby determining the optimal parameters. The test results show that the thermally treated nonwoven fabrics have better mechanical properties and FIR emissivity, compared to those of non-thermally treated nonwoven fabrics. Moreover, more FPET fibers cause the mechanical properties along the cross machine direction (CD) to decrease by 9% and that along the machine direction (MD) to decrease by 5%. In particular, all the thermally treated samples exhibit a FIR emissivity of 0.8, which is health-promoting.

The combination of functional electrical products improves the value of textiles, including measurement, detection, and communication. These added values, however, have a negative influence on comfort and consumer acceptance. This study proposes using a knitting technique and conceals the circuit that connects electrical components inside the textiles, thereby ensuring satisfactory comfort and mechanical properties. The pattern designed using a crochet machine is applied to the preparation of conductive elastic knits. During the process, different numbers and types of conductive yarns are incorporated. The stiffness, tensile strength, elastic response rate, air permeability, and electrical resistance of conductive elastic knits are evaluated. The rigidity and electrical resistance test results show that increasing the numbers of conductive yarns results in a lower electrical resistance, as well as a rugged knit surface and exposure of the yarns. Moreover, increasing the numbers of conductive yarns does not pertain to the physical properties of elastic knits, according to the results of air permeability, tensile strength, and elastic recovery tests.