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Melt-blown nonwoven fabrics for filtration are usually manufactured using polypropylene, but after a certain time period the middle layer of the mask may have a reduced effect on adsorbing particles and may not be easily stored. Adding electret materials not only increases storage time, but also shows in this study that the addition of electret can improve filtration efficiency. Therefore, this experiment uses a melt-blown method to prepare a nonwoven layer, and adds MMT, CNT, and TiO2 electret materials to it for experiments. Polypropylene (PP) chip, montmorillonite (MMT) and titanium dioxide (TiO2) powders, and carbon nanotube (CNT) are blended and made into compound masterbatch pellets using a single-screw extruder. The resulting compound pellets thus contain different combinations of PP, MMT, TiO2, and CNT. Next, a hot pressor is used to make the compound chips into a high-poly film, which is then measured with differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The optimal parameters are yielded and employed to form the PP/MMT/TiO2 nonwoven fabrics and PP/MMT/CNT nonwoven fabrics. The basis weight, thickness, diameter, pore size, fiber covering ratio, air permeability, and tensile property of different nonwoven fabrics are evaluated in order to have the optimal group of PP-based melt-blown nonwoven fabrics. According to the results of DSC and FTIR measurements, PP and MMT, CNT, and TiO2 are completely mixed, and the melting temperature (Tm), crystallization temperature (Tc) and endotherm area are changed accordingly. The difference in enthalpy of melting changes the crystallization of PP pellets, which in turn changes the fibers. Moreover, the Fourier transform infrared (FTIR) spectroscopy results substantiate that PP pellets are well blended with CNT and MMT, according to the comparisons of characteristic peaks. Finally, the scanning electron microscopy (SEM) observation suggests that with a spinning die temperature of 240 °C and a spinning die pressure lower than 0.01 MPa, the compound pellets can be successfully formed into melt-blown nonwoven fabrics with a 10-micrometer diameter. The proposed melt-blown nonwoven fabrics can be processed with electret to form long-lasting electret melt-blown nonwoven filters. [ABSTRACT FROM AUTHOR]

In this study, nonwoven fabrics, rigid polyurethane foam (RPUF), Basalt woven fabrics, and an aluminum foil film mold are used to produce multi-functional composite sheets with flame-retardant, sound-absorbing, and electromagnetic-shielding functions. The nonwoven layer is composed of Nomex fibers, flame-retardant PET fibers, and low-melting-point (LMPET) fibers via the needle rolling process. The optimal Nomex fiber/flame-retardant PET fiber/LMPET fiber (N/F/L) nonwoven fabrics are then combined with rigid polyurethane (PU) foam, Basalt woven fabric, and an aluminum foil film mold, thereby producing nonwoven/rigid polyurethane foam/Basalt woven fabric composite sheets that are wrapped in the aluminized foil film. The test results indicate that formed with a foaming density of 60 kg/m3 and 10 wt% of a flame retardant, the composite sheets exhibit electromagnetic interference shielding efficacy (EMI SE) that exceeds 40 dB and limiting oxygen index (LOI) that is greater than 26. The efficient and highly reproducible experimental design proposed in this study can produce multifunctional composite sheets that feature excellent combustion resistance, sound absorption, and EMI SE and are suitable for use in the transportation, industrial factories, and building wall fields. [ABSTRACT FROM AUTHOR]

Conventional personal protective equipment is usually made in multilayer stacks, and appears clumsy and uncomfortable, offering limited protection. In recent years, a newly-developed nanosuspension, shear thickening fluids (STFs), has been commonly applied to buffer and shock absorption. In this study, nonwoven fabrics are impregnated with 30 wt%, 35 wt%, or 40 wt% STF in order to strengthen the interaction among fibers. The resultant STF composite nonwoven fabrics are observed for their morphology, and tested for their tensile strength, tearing strength, bursting strength, and dynamic impact resistance, thereby examining the damage resistance of the materials. The SEM images indicate that the fibers are adhered with a tremendous amount of silicon dioxide (SiO2) particulates with a rise in the STF concentration, due to which the smooth fibers become rough. Moreover, the mechanical test results indicate that a rise in the STF concentration improves the frictional force during the relative motion of fibers, which subsequently mechanically strengthens the STF composite nonwoven fabrics. The dynamic impact test results show that when the STF concentration increases from 30 wt% to 35 wt%, the materials exhibit dynamic impact strength that is significantly improved to 51.9%. Nonetheless, significant improvement in dynamic impact strength is absent when the STF concentration increases to 40 wt%. To sum up, a critical value of STF concentration has a positive influence over the mechanical strengths of STF composite nonwoven fabrics. [ABSTRACT FROM AUTHOR]

Inspired by pomelo peel, this study designs an effective cushioning composite with a novel sandwich structure using a columnar lattice mold and two-step foaming technique. This sandwich composite consists of a polyamide nonwoven fabric (i.e. nonwoven surface) as the surface reinforcement layer and a double-layered spacer fabric as the bottom layer for energy absorbing. The static-compression resistance and dynamic cushioning efficacy of composites are investigated, examining the influences of three parameters (i.e. the areal density of the nonwoven surface and laminating angle and the mesh size of the double-layered spacer fabric). The experimental results show that the static-compression resistance and dynamic cushioning efficacy of the composites decrease when increasing the laminating angle of the spacer fabric and the areal density of the polyamide nonwoven fabric. By contrast, with an increment in mesh size, the compression resistance and cushioning efficacy of the composites first decrease and then increase. N200PUH/L(S5) consists of a 200 g/m2 nonwoven surface and a 0° laminated angle, 5 mm mesh size double-layered spacer fabric, which exhibits a higher cushioning efficacy than the pomelo peel. The acceleration of N200PUH/L (S5) was 39 g at 15 ms, and the acceleration of pomelo peel was 72 g at 7 ms, which were 60.7% and 28.5% lower than that of the blank group, respectively. The sandwich-structured composites are proven to have promising applications for low-velocity cushioning behavior, and this study combines the textile structure and foam technique, offering a perspective of designing cushioning composite sandwiches for future studies. [ABSTRACT FROM AUTHOR]

This study investigated eco-friendly antibacterial medical protective clothing via the nonwoven process and characteristic evaluations. Firstly, Tencel® fibers and low melting point polyester (LMPET) fibers (re-sliced and granulated from recycled PET bottles) were mixed at different ratios and then needle punched at diverse needle rolling depths. The influences of manufacturing parameters on the Tencel®/LMPET nonwoven fabrics were examined in terms of mechanical properties, water vapor transmission rate, and stiffness. Next, Tencel®/LMPET nonwoven fabrics were combined with thermoplastic polyurethane (TPU)/Triclosan antibacterial membranes that contained different contents of triclosan using melt processing technology. The resulting Tencel®/LMPET/TPU/Triclosan composites were characterized via different measurements; an optimal bursting strength of 86.86 N, an optimal horizontal tensile strength of 41.90 N, and an optimal stiffness along the MD and CD of 8.60 cm were recorded. Furthermore, the Tencel®/LMPET/TPU/Triclosan composites exhibited a distinct inhibition zone in the antibacterial measurement, and the hydrostatic pressure met the requirements of the EN 14126:2003 and GB 19082-200 disposable medical protective gear test standards. [ABSTRACT FROM AUTHOR]

With the development of modern electronic technology, there is an urgent need to prepare multifunctional polymer composite materials with flame retardant and electromagnetic shielding functions. Herein, use the chemical activity of polydopamine (PDA) to modify polyphenylene (PP) fabric to enhance its interface compatibility. Then, the dipping method was used to achieve the successful deposition of Ag nanoparticles on the surface of the PP non‐woven fabric, and by adjusting the concentration of the Ag precursor and the immersion time of the flame retardant constructed a conductive composite material with lightweight, flexible and has good flame retardant properties. The results showed that when the concentration of AgNO3 solution was 2% and the thickness was 0.166 mm, the average shielding effectiveness shielding effectiveness (SE) and SSE/t of the composite fabric reached 25.01 dB and 6097.56 dB cm2g−1, respectively. In particular, the composite fabric still maintained stable electrical conductivity after flame retardant treatment, and the average shielding effectiveness SE and SSE/t of the composite fabric reached 20.20 dB and 1518.80 dB cm2 g−1. The multifunctional conductive composite fabric prepared in this study has broad development prospects in the fields of electromagnetic shielding and smart wear. [ABSTRACT FROM AUTHOR]

In this study, a low-melting-point polyester nonwoven fabric (L), a nylon spacer fabric (N), and a carbon fiber woven fabric (C) are laminated in different orders and then needle-bonded at a depth of 15.0 cm to form NLC, NLN, CLC, and CLN composites with a sandwich construction. Regardless of the lamination order, four composite types exhibit high tensile strengths and tearing strengths. Based on the ASTM D4935-18 test standard, the electromagnetic wave shielding measurement is conducted in a frequency range of 1~3 GHz. The two groups—NLC and CLN—demonstrate different electromagnetic wave shields, which are −45~−65 dB for the former, and −60 dB for the latter. According to FTTS-FA-003, in the specified requirements of the test method for electromagnetic shielding textiles, the proposed composites achieve level III, which is the highest standard, and are thus qualified for use in the aviation, construction, and commerce fields. [ABSTRACT FROM AUTHOR]

This study proposes a high‐resilience foam‐core composite with bionic micro‐interface lattice structure using columnar lattice mold and two‐step foaming technique. This foam‐core composite uses polyamides nonwoven fabrics as the bionic surface layers and polyurethane foam as the bionic core layer. The foam cavity diameter and columnar interface area are adjusted by the polyols content and the column diameter, respectively. Effects of the cavity diameter and the column diameter on the compression resistance, static‐bursting strength, low‐velocity impact, and dynamic cushion efficacy of foam‐core composites are investigated. The results show that compression resistance, bursting strength, and cushion efficacy of the foam‐core composites are all increased by degrees with the cavity diameter when the content of polyols increases. When the cavity diameter was 195 μm, bionic micro‐interface foam‐core composite absorbed 99% low‐velocity impact energy. Existence of bionic micro‐interface lattice obviously improved the static compression and bursting properties. Bionic micro‐interface foam‐core composites with 16 mm‐diameter column have the lower and wider contact force peak compared to pomelo, 8 mm and 12 mm‐diameter column, indicating higher dynamic cushion efficacy. The resulted composite provides an idea of establishing bionic foam‐core cushion composites by foam interface, which is expected to be used as energy absorption material for commercial application. [ABSTRACT FROM AUTHOR]

People are no longer satisfied with only comfortable textile clothing with advanced technology and elevated standard of living and, thus, are gradually preferring functional textiles. In the meanwhile, the spread of medical knowledge has educated the public about the antimicrobial concept. In this study, composed of different twist coefficients and different numbers of plies, the zinc ion twisted yarns are made into knitted fabrics. Next, the knitted fabrics are examined for water vapor transmission rate and antimicrobial efficacy. The test results indicate that the water vapor transmission rate is 1013 g/m2/day for 2Zn-0C-K and 981 g/m2/day for 3Zn-0C-K. However, a rise in the twist coefficient adversely affects the water vapor transmission rate. The fabric 2Zn-3C-K exhibits the maximal air permeability of 265 cm3/cm2/s and 3Zn-3C-K 186 cm3/cm2/s. Regardless of whether it is at OD600, colony count observation, or antibacterial rate, 3Zn-5C-K exhibits the maximal antibacterial rate with the value being 0.45 at OD600 and the optimal antimicrobial efficacy being 85%. To sum up, based on the interest of the test results, production cost, and manufacturing process evaluation, 2Zn-5C-K is the optimal nonwoven fabric that achieved the maximal effects. [ABSTRACT FROM AUTHOR]

Nylon fabrics are used as the reinforcing upper layer. A warp-knitted spacer fabric that is saturated with flexible polyurethane foam is used as the lower layer. They are combined in order to form innovative impact energy absorbent composite sandwiches employing a two-step foam process. The quasi-static compressive strength, bursting strength, and dynamic shock cushioning characteristic of the composite sandwiches are evaluated, the latter of which is tested using a drop weight impact tester in order to simulate the impact resistance corresponding to complex environments. The experimental results suggest that a combination of warp-knitted spacer fabric increases the compressive strength and bursting strength of composite sandwiches by 107% and 60%, respectively. The shapes of impactors determine the contact force and dynamic impact time. The greater contact area results in the smaller contact force, indicating that the composite sandwiches have greater cushioning efficacy. Designed with a gradient combination, the flexible polyurethane foam strongly bonds the upper polyamide nonwoven fabric and the lower warp-knitted spacer fabric. The optimal compression resistance, a bursting strength of 1677 N, and a maximum energy absorption of 90% at a 15 J impact energy are presented. The innovative composite sandwiches have a promising perspective in packaging and individual impact protection in the future. [ABSTRACT FROM AUTHOR]

The study employs the mechanical interlocking theory and hot pressing treatment to generate nonimpregnation of highly rebounding composites. This design preserves the high flexibility, elasticity, and stability of elastic polymer while reserving the skin-friendly feature, resilience, and recovery of the highly elastic nonwoven fabrics without using an adhesive. During the preparation of highly rebounding composites, elastic polymers are hot pressed to form films, after which they are combined with highly elastic nonwoven fabrics. The composites are then examined in terms of the mechanical properties and the level of adhesion. Fluffy nonwoven fabrics and elastomer polymers are hot pressed in order to obtain better adhesion and puncture resistance. The tensile and hammer rebound rate test results show that highly rebounding composites that are reinforced using stiff nonwoven fabrics exhibit greater resilient and tensile properties. Comparing to pure nonwoven fabrics, the proposed highly rebounding composites have a structure that is 1.5 time greater compactness, as well as 1.5 times greater a tensile strength and 1.6 time greater resilience. Namely, they provide great variety according to the users' ends as their performances are better and adjustable. For example, shallowly or deeply needle punched nonwoven fabrics can be separately used in the garments or cushions. The proposed highly rebounding cushion composites are protective materials and are suitable for the application as in cushions, packaging, and buffering protective equipment. [ABSTRACT FROM AUTHOR]

The aim of this study is to combine conductive polymer composite with conductive fabrics for the acquisition of electromagnetic interference shielding effectiveness (EMI SE) materials. HS-PET filaments, 316 L stainless steel (SS) wires, and bamboo charcoal (BC) roving are made into woven fabrics and knitted fabrics. Unlike the nonwoven fabrics that consist of entangled staple fibers, the resulting shielding materials have greater air permeability. Accordingly, HS-PET filaments, 316 L SS filaments, and BC roving are made into conductive yarns with different twists per inch (T.P.I.) using a ring spinning manufacture. The conductive yarns are made into woven and knitted fabrics, the electromagnetic interference shielding effectiveness (EMI SE) of which are then evaluated in order to examine the influences of the number of fabric layers, lamination angle, and laminated fabric type. The test results show that with a T.P.I being 8, the conductive yarns have an optimal tensile strength of 43.74 N with the lowest CV% of 4.72%. In the meantime, the conductive yarns have good uniformity but do not demonstrate any significant trend on the linear resistance. In addition, the conductive woven fabrics have better tensile strength along the weft direction (712.49 N). Regardless of whether it is a woven fabric or a knitted fabric, the surface resistivity is 107 Ω/sq. Single-layered knitted fabrics have the optimal air permeability (262.6 cm3/s/cm2), and the three-layered woven fabrics laminated at angle of 0°/90°/45° exhibit the maximum EMI SE (-45.96 dB). Therefore, the three parameters are correlated with the metallic conductive network that directly changes the EMI SE of the resulted fabrics and composites. [ABSTRACT FROM AUTHOR]

The textile industry is indispensable to our lives, and the ongoing development of related products also results in an increasing amount of textile waste, especially selvages that account for the majority of textile waste. This study proposes making nonwoven composites with recycled high-strength polyester (HPET) fibers and polypropylene (PP) fibers using needle punching and thermal treatment. One-way ANOVA and multiple regression analysis are employed to analyze the correlation between mechanical properties of nonwoven composites and influencing parameters of fiber blending ratios, needle punching depths, and temperature of thermal treatment. In particular, the HPET/PP nonwoven composites have optimal mechanical properties when the fiber blending ratio is 60/40 (wt%) and the needle punching depth is 19 mm. Moreover, the statistical analyses indicate that the factors that affect the properties are ranked as the intrinsic properties of materials, followed by manufacturing parameters. [ABSTRACT FROM AUTHOR]

In this study, the thicknesswise fibers of the low-melting polyethylene terephthalate (LPET) nonwoven fabrics are needle punched and intertwined with the intra-laminar basalt fibers (BF) of basalt plain woven fabric in order to strengthen the stab-resistant property of LPET/BF sandwich composites as well as to fabricate armor that is composed of less lamination layers. Two LPET nonwoven fabrics and a BF plain woven fabric as an interlayer are laminated and combined using a needle-punch reinforcing method. The response surface analysis based on the Box–Behnken design is used to examine the influences of structure parameters of low-melting PET nonwoven fabrics including areal density (AD) and manufacture parameters including needle punching density (ND), and depth of needle punch (DP) on the spike stab resistance, knife stab resistance, bursting resistance, and tensile property. An empirical regression model of AD, ND, and DP is thereby established. The test results show that the bursting strength and quasi-static stab resistance of sandwich composites are highly dependent on AD and ND. Likewise, DP has a significant influence on the knife stab resistance and bursting strength, while the tensile strength is solely dependent on ND. According to the empirical regress model, the acquired optimal needle punching parameters of sandwich composites are an AD of 400 g/m2, ND of 143.77 needles/cm2, and DP of 6.41 mm. The 95% confidence interval yielded by the empirical regression model is in conformity with the test results. The empirical regression model of the stab resistance is proven to provide effective prediction of the number of lamination layers required by armor in the future. [ABSTRACT FROM AUTHOR]

Nonwoven fabrics have been fabricated for oil–water separation, but simplifying the manufacturing processes is still a challenge. In this work, a facile and easily scaled up approach based on thermal bonding and one‐step solution immersion has been successfully developed to prepare nonwoven fabrics with high separation efficiency and flux of oil. Here, polypropylene (PP) and low‐melt‐point polyester (LPET) fibers with a unique sheath–core structure are employed to form PP/LPET nonwoven fabrics. Thermal bonding by hot press and hydrophobic treatment with 1H,1H,2H,2H‐perfluorodecyl‐1‐thiol (PFDT) are used to manufacture oil–water separation nonwoven fabrics. Effects of the ratio of LPET fibers and the concentration of PFDT are discussed in terms of mechanical properties, morphology, surface chemical composition, water contact angle and performance of oil–water separation and flux of the nonwoven fabrics. The results show that the strength of the nonwoven fabrics gradually increases with increasing ratio of LPET fibers. After immersion in PFDT, the nonwoven fabrics show high hydrophobicity with a water contact angle of 143°. They can be used to separate oil–water mixtures. The separation efficiency is 97–99% and the oil flux is 62 364.92 L m−2 h−1. This study provides a new prospect for simple introduction of a hydrophobic agent on a nonwoven fabric to achieve various functional oil–water separation materials. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The combination of appropriate materials and structural design can compensate for flaw of a single pattern, providing the products with better functionalities. In this study, the custom-made nonwoven fabric machine can unwrap the filament tows before needle punching stage. Sandwich composites are proposed, consisting of two nonwoven fabrics as surface layers and laminated loops of filaments as the core. The puncture resistance of the sandwich composites are examined in terms of weight of filament loops and needle-punching depth, examining their influences. The employment of filaments has a remarkable influence on the mechanical performance of the composites. GF4G has static puncture resistance, dynamic puncture resistance, and bursting strength that are 89%, 30%, 88% higher than those of GF1G; 332%, 127%, and 500% higher than those of 2G; and 671%, 400%, and 1260% higher than those of G. Using filaments to reinforce nonwoven fabrics only requires simple equipment and easy operation. Furthermore, based on the requirements of different final products, diverse filaments and multiple parameters can be combined, thereby providing the composites with efficient production, solid reinforcement, and broad applications. [ABSTRACT FROM AUTHOR]

Fiber-reinforced polymer composites are commonly used in different fields because the evenly distributed fibers in polymer can efficiently transmit the load of a force and mechanically reinforce the polymer matrices. This study proposes producing composite sandwiches using thermoplastic polyurethane sheets as the top and bottom layers and a polypropylene/Kevlar nonwoven fabric the interlayer. Thermoplastic polyurethane sheets and a polypropylene/Kevlar nonwoven fabric are combined using the sheet extrusion method, during which the polypropylene staple fibers are melted and firmly bond the thermoplastic polyurethane sheets. The mechanical properties, thermal behavior, and surface morphology of composite sandwiches are evaluated, examining the influence of parameters. The test results show that the composite sandwiches are mechanically reinforced as a result of using the nonwoven covers. Moreover, the improved interfacial bonding between the cover layers and the interlayer inhibits delamination, and the stabilized structure subsequently decreases the level of combustion which is in conformity of the differential scanning calorimetry results. The manufacturing is creative and efficient due to one-step shaping, creating a refined composite sandwich with good mechanical properties and combustion resistance. [ABSTRACT FROM AUTHOR]

Abstract This study investigates the mechanical properties and damage behavior of flexible laminated composites. Needle punching is performed to combine woven Kevlar fabric and two nonwoven low-melting point polyester (LMPET) fabrics into a fabric interlayer. A sheet-extrusion machine is used to bond two thermoplastic polyurethane (TPU) sheets on each side of a fabric interlayer. The tensile strength, peel load, and static puncture resistance of the flexible laminated composites are evaluated, and the influences of needle-punching rates and depths are examined. Test results show that a high needle-punching rate or depth positively affects tensile strength by promoting fiber entanglement. The tensile strength of the 300-15 group reaches 24.70 MPa. Moreover, when the needle-punching depth does not exceed 11 mm, melted LMPET fibers help bond two-phase materials and thus increase the peel loads of the final composites. The 200-11 group has an optimal puncture resistance of 5.86 N. The combination of TPU sheets and woven Kevlar fabrics yields flexible laminated composites with good static puncture resistance. The results of this study can be applied to improve the performance of flexible laminated composites. [ABSTRACT FROM AUTHOR]

This study aims to investigate the mechanical properties, far-infrared (FIR) emissivity, and limiting oxygen index (LOI) of FIR ray/low-melting-point (LM) nonwoven fabrics, flame retardant (FR)/LM nonwoven fabrics, and FIR/FR/LM composite nonwoven fabrics, which are with or without heat treatment and also investigating the effect of heat treatment on the LM polyethylene terephthalate (PET) fibers. Test results show that for FIR/LM nonwoven fabrics, applying heat treatment leads to the better mechanical properties and FIR emissivity of 0.90. For FR/LM nonwoven fabrics, unheat-treatment samples have greater mechanical properties and an LOI of 34. For FIR/FR/LM composite nonwoven fabrics, the unheat-treated samples exhibit greater tensile properties, but the heat-treated samples exhibit greater puncture resistance, burst strength, and FIR emissivity. The structural parameters of the composite nonwoven fabrics can be adjusted according to the demand of users in terms of FIR emissivity and flame retardancy, and the composite nonwoven fabrics are thus expected to be used as construction materials for medical systems. [ABSTRACT FROM AUTHOR]

Nonwoven fabrics were used as reinforcement to laminated composites to improve the mechanical properties and damage behaviors. The needle-punched Kevlar/LMPET nonwoven interlayer and two TPU covers were combined via thermal bonding to form the laminated composites. Tensile strength, peel load, and static puncture resistance of the laminated composites were evaluated in terms of needle punching rate and depth of the nonwoven interlayer. Results showed that tensile strength and static puncture resistance depended on the needle punching depth, primarily on the tangled fiber points. The peel load was dependent on the needle punching rate, especially on the resulting melted LMPET fibers. The laminated composites exhibited desirable tensile properties, peel load, and static puncture resistance. [ABSTRACT FROM AUTHOR]

This study proposes to make geotextiles from recycled materials. Polyester fibers, recycled polyester fibers, and low melting point polyester fibers are blended and needle punched to make the polyester fabrics, the mechanical properties of which are then evaluated to determine the optimal parameters. The polyester nonwoven fabrics are needle punched with various densities. Afterwards, the resulting polyester nonwoven fabrics, glass fiber woven fabrics, and polypropylene selvages are combined, needle punched, and hot pressed to form geotextiles, the properties of which are tested by tensile strength, tearing strength, burst strength, puncture strength, and water resistance tests. The test results show that polyester fabrics containing 50 wt% of polyester fibers have the optimal mechanical properties. Furthermore, needle punching at 90 needles/cm2 results in a greatest increase in mechanical properties of the polyester nonwoven fabrics. The tensile strength, tearing strength, and water resistance of the geotextiles increase as a result of hot pressing, and the bursting strength and puncture resistance are primarily associated with the needle punching densities. This study successfully creates composite geotextiles with reinforced mechanical properties by needle punching and hot pressing recycled polyester fabrics and polypropylene selvages. [ABSTRACT FROM AUTHOR]

Geotextiles primarily provide reinforcement, and their tensile properties can resist stresses and prevent soil structure deformation. Nonwoven geotextiles are also commonly used in railways, roads, soil and water conservation, and therefore their applications are subjected to climatic environments and geographical environments where the geotextiles are used. Therefore, this study recycles and reclaims Kevlar selvages that are then incorporated with polyester fibers and low-melting-point polyester fibers in order to form nonwoven geotextiles. The tensile properties of the geotextiles in relation to various ambient environmental temperatures are examined with the test temperatures being set as 25℃ (control group), 50, 60, 70, and 80℃. Statistical analyses are performed to examine the effects of fiber blending ratios, needle punching depth, and thermal treatments on the tensile properties of the nonwoven geotextiles. The test results indicate that nonthermally treated nonwoven geotextiles have a tensile strength that is significantly increased when the ambient temperature is increased. In contrast, according to the insignificant differences obtained from statistical analyses, the tensile strength of thermally treated samples is independent of the ambient temperatures, indicating that thermal treatment allows for heat setting of the geotextiles. In particular, the thermally treated polyester/low-melting-point polyester/Kevlar nonwoven geotextiles have the maximum tensile strength when they are composed of a blending ratio of 60/20/20 wt% and a needle punching depth of 0.5 cm. [ABSTRACT FROM AUTHOR]

In order to realize recycling of polypropylene selvages, polypropylene nonwoven selvages with different plied orientation were inserted between Kevlar/Nylon/low-melting polyester nonwoven fabrics forming composite nonwoven. Low-melting polyester content of nonwoven fabric and hot-pressing temperature of composite nonwoven were both optimized after static and dynamic puncture resistances. Moreover, effects of hot-pressing and plied orientation on static and dynamic puncture resistances, sound absorbing and thermal insulating properties of composite nonwoven were discussed respectively. Result shows that, optimal low-melting polyester fiber content was 30%, and best hot-pressing temperature for composite nonwoven was 180°C. Polypropylene nonwoven selvages improved static puncture resistance, sound absorbing and thermal insulating properties. Hot-pressing slightly increased puncture resistance and obviously improved thermal insulation, but decreased sound absorption coefficient significantly. Plied orientation affected static and dynamic puncture resistance insignificantly, but influenced on sound-absorbing and thermal-insulating properties significantly. When composite nonwoven was plied with 90°/90° polypropylene selvages and hot-pressed at 180°C, the static and dynamic puncture resistances reached 120 N and 80 N, respectively, and thermal conductivity was 0.047 W/mK. Five layers of composite nonwoven before hot-pressing had sound absorption coefficient of above 0.94 at frequency of higher than 1890 Hz. [ABSTRACT FROM AUTHOR]

This study examines how inter/intra-ply hybrid structures influence the impact load of sandwich-structured flexible composites determined by static or low-velocity impact tests. The flexible composites are composed of nylon/high-resilient non-woven polyester fabrics as the surface sheet and polyurethane foam as the core layer. The polyurethane foam layer has a specified thickness and density, while the surface layers comprise various fiber blending ratios, different blending methods, different lamination procedures and lamination orders. The test results show that the flexible composites have an optimal impact absorption of 1901 N for a static impact when the nylon/high-resilient polyester non-woven fabrics are composed of an inter-ply hybrid structure. In contrast, they have an optimal impact absorption of 8255 N for a low-velocity impact when the nylon/high-resilience polyester non-woven fabrics are composed of an intra-ply hybrid structure. [ABSTRACT FROM AUTHOR]

Cloth diapers also known as eco-diapers, traditional sandwich-structured eco-diapers are composed of top and bottom layers that are made of cotton or polyester nonwoven fabrics. On account of the hydrophilic bottom layer, urine permeates when the water absorption reaches saturation. In this study, polypropylene is melt-blown into hydrophobic polypropylene nonwoven fabrics to be used as the top and bottom layer. Polypropylene is hydrophobic but after being fabricated into nonwoven fabrics, the porous structure enables the urine to leak to the absorbent interlayer of eco-diapers. Hence, the top layer of diaper does not contain urine, which makes smart diapers more comfortable than cloth diapers that are made of cotton or other moisture-absorbent materials. Moreover, the sensing mechanism via Bluetooth module can detect the water content of the interlayer with a view to improving the demerit of urine leakage. The interlayer is the sensing layer that has antibacterial function. Two types of antibacterial yarns are treated by zinc oxide and silver ions. The yarns are fabricated into antibacterial woven fabrics, after which the antibacterial properties of fabrics are investigated with quantitative and qualitative tests. Next, two parallel metallic wires are assembled in order to trigger short circuit when sensing moisture, thereby obtaining different electric resistance based on different moisture levels. Furthermore, the miniature senor can signify the cellular phones or buzzers when the two metallic wires generate electrical resistance due to the presence of urine. The metallic wires are silver-plated copper yarns, stainless steel fibers, and copper fibers, which possess different electric resistance for the corresponding miniature sensors. This study proposes an efficient manufacture of smart diapers that require only a combination of woven fabrics and two metallic wires to sense moisture, the design of which can be encompassed in diverse fields. [ABSTRACT FROM AUTHOR]

The area of forests continues decreasing while the water/soil loss becomes worse. In these complicated environments, mechanical properties, stability, high modulus and low elongation of geotextiles are required. On a premise of the acquisition of good mechanical properties and the improvement in the deformation and puncture resistance of nonwoven fabric, woven/nonwoven hybrid geotextiles are designed and made with needle punch processing technology in this study. The test results indicate that the mechanical properties of hybrid geotextiles are improved significantly when the areal density of nylon fabrics is increased. In particular, with the areal density of 400 g/m2, hybrid geotextiles exhibit the maximal mechanical properties and puncture resistance. Moreover, the pore fraction of hybrid geotextiles decreases as a result of a rise in the areal density of nylon top/bottom layers. The use of a 3 D mesh fabric as the interlayer provides the needle punched composite geotextiles with the highest tensile resistance, puncture resistance. The composite geotextiles are treated with acid and alkali to simulate the corrosion under natural conditions of stabilized soil. The resultant geotextile has good mechanical properties and acid/alkali degradation resistance. This allows the hybrid geotextiles to stabilize water and soil conservation in complicated conditions. [ABSTRACT FROM AUTHOR]

A green approach for forming silver nanoparticles (Ag NPs) on ecofriendly highly absorbent nonwoven fabrics was investigated. The fiber blending ratio of highly absorbent nonwoven fabrics was optimized by simulated body fluid (SBF) and water absorption. SBF and water absorption ratios reached 42 and 42.9 times after addition of 50 wt% highly absorbent fibers. The Ag NPs were characterized by UV-visible spectrometry (UV-Vis), X-ray diffraction (XRD) and transmission electron microscopy (TEM). UV-Vis and XRD images confirmed the presence of Ag NPs. TEM observation revealed that Ag NPs were distributed at 5-10 nm. The results of antimicrobial activity showed that Ag NP dope is effective for producing antimicrobial nonwoven fabrics against E. coli and S. aureus. [ABSTRACT FROM AUTHOR]

Recycled high-modulus Kevlar fibers were blended with Nylon 6 staple fibers and biocomponent low-Tm/high-Tm polyester fibers to form high-modulus puncture-resistance nonwoven fabrics via opening, mixing, carding, lapping, needle-punching, as well as hot-pressing processes. In this paper, biocomponent low-Tm/high-Tm polyester fiber content, needle-punching density, and hot-pressing temperature were changed to evaluate the tensile strength, bursting strength and static puncture resistance of resulting nonwoven fabrics as related to aforementioned three parameters based on response surface methodology. The result shows that the tensile strength is highly related to needle-punching density and hot-pressing temperature; but the bursting strength and static puncture resistance are significantly involved with the aforementioned three parameters. The tensile strength, bursting strength, and static puncture resistance all present increasing and then decreasing trend with increase of its respective concerning parameters. Moreover, the static puncture resistance strength has linear dependence on bursting strength. [ABSTRACT FROM AUTHOR]

The practice of covering the roof of a building with a layer of living vegetation has many benefits. However, soil is heavy and most soil substitutes present special problems such as a tendency to block drains. Previous studies utilized a lightweight, soil-free growing medium that replaced actual soil to lessen the mechanical load on the roof. This study used a lightweight nonwoven fabric as a growing medium for living roofs. Two types of polyester fibers were blended at various ratios and then thermally dried into various densities. A desirable growing medium must resist moisture deformation and encourage root implantation. The results indicated that 0.030 g/cm3 was the optimum density and that the weight of low-melting-point polyester fibers had to be in excess of 20 wt%. It was anticipated that the manufacturer who adjusts factory parameters to benefit from this research will reduce the production cost. [ABSTRACT FROM AUTHOR]

Serving as matrices, polypropylene (PP) melt-blown nonwoven fabrics with 4% electrostatic electret masterbatch were incorporated with a 6%, 10%, 14%, or 18% phosphorus-nitrogen flame retardant. The test results indicate that the incorporation of the 6% flame retardant prevented PP melt-blown nonwoven fabrics from generating a molten drop, which, in turn, hampers the secondary flame source while increasing the fiber diameter ratio. With a combination of 4% electrostatic electret masterbatch and the 6% flame retardant, PP melt-blown nonwoven fabrics were grafted with ZIF-8 and Ag@ZIF-8. The antibacterial effect of ZIF-8 and Ag@ZIF-8 was 40% and 85%, respectively. Moreover, four reinforcing measures were used to provide Ag@ZIF-8 PP melt-blown nonwoven fabrics with synergistic effects, involving lamination, electrostatic electret, and Ag@ZIF-8 grafting, as well as a larger diameter because of the addition of phosphorus-nitrogen flame retardants. As specified in the GB2626-2019 and JIS T8151-2018 respiratory resistance test standards, with a constant 60 Pa, Ag@ZIF-8 PP melt-blown nonwoven membranes were tested for a filter effect against PM 0.3. When the number of lamination layers was five, the filter effect was 88 ± 2.2%, and the respiratory resistance was 51 ± 3.6 Pa. [ABSTRACT FROM AUTHOR]

In recent years, air filtration has been gaining much attention, and now people are much more concerned about antibacterial filters due to the spreading of COVID-19. The electret polypropylene (PP) nonwoven fabrics possess excellent filtration efficiency but a limited antibacterial effect against S. aureus and E. coli, and therefore triclosan is used in this study. Serving as an antibacterial agent, triclosan with a low molecular weight is an effective additive for the test results, indicating that the presence of triclosan strengthens the antibacterial effects of the filters. In addition, triclosan also strengthens the PP's crystallinity, which in turn betters the filtration efficiency of the filters concurrently. Demonstrating powerful filtration and antibacterial performances, the antibacterial electret PP filters are highly qualified for filter applications. [ABSTRACT FROM AUTHOR]

With the development of technology, fibers and textiles are no longer exclusive for the use of clothing and decoration. Protective products made of high-strength and high-modulus fibers have been commonly used in different fields. When exceeding the service life, the protective products also need to be replaced. This study proposes a highly efficient recycling and manufacturing design to create more added values for the waste materials. With a premise of minimized damage to fibers, the recycled selvage made of high strength PET fibers are reclaimed to yield high performance staple fibers at a low production cost. A large amount of recycled fibers are made into matrices with an attempt to decrease the consumption of new materials, while the combination of diverse plain woven fabrics reinforces hybrid-fabric fibrous planks. First, with the aid of machines, recycled high strength PET fibers are processed into staple fibers. Using a nonwoven process, low melting point polyester (LMPET) fibers and PET staple fibers are made into PET matrices. Next, the matrices and different woven fabrics are combined in order to form hybrid-fabric fibrous planks. The test results indicate that both of the PET matrices and fibrous planks have good mechanical properties. In particular, the fibrous planks yield diverse stab resistances from nonwoven and woven fabrics, and thus have greater stab performance. [ABSTRACT FROM AUTHOR]

As a replacement for mineral materials, geotextiles have been pervasively used in civil engineering so as to provide separation and filtration. This study aims to recycle Kevlar selvages for the preparation of nonwoven geotextiles. The effects of fiber types and manufacturing processing are examined in terms of pore size, water permeability, and shear resistance (bursting strength, and puncture strength). The test results and statistical analyses indicate that a combination of 20 wt% Kevlar fibers, 60 wt% three-dimensional crimped polyester (PET) fibers, and 20 wt% low-melting-point PET (LMPET) fibers creates geotextiles that have a small pore size, good water permeability, and good shear resistance. These geotextiles prevent soil loss, and have greater water permeability and a higher resistance to sharp objects. [ABSTRACT FROM AUTHOR]

Abstract: An economical and flexible compound fabric was prepared using Kevlar fabric and glass fabrics as well as recycled Kevlar/Nylon/low-Tm polyester nonwovens via needle-punching and thermal-bonding processes. Effects of Kevlar staple fibers fraction, number of layers and inter-laminar bonding on the static and dynamic puncture resistances were comparatively studied. Findings indicate that increase of Kevlar staple fibers fraction improved static puncture resistance more significantly, but inter-laminar shear effect influenced on dynamic puncture resistance more evidently. With 20wt% recycled Kevlar fibers, static puncture resistance had linear relation to number of layers, but dynamic puncture resistance showed a parabolic relationship. The contacting pressure and friction strength of compound fabric to probe was to resist against static puncture resistance, but mechanism for dynamic puncture resistance was due to fiber elongation of fabric interlayer and compactness of compound fabric. Yarn brittle-breakage was the main dynamic puncture resistance mechanism for G-CF, but pushing fiber apart was for K-CF, besides of contact pressure of probe to compound fabrics. The improved both of static and dynamic puncture resistances were attributed to cut resistance of Kevlar fibers and compactness of fiber assembles. Comparatively, cut resistance property of Kevlar fibers related to dynamic puncture behavior more significantly, but fiber compactness affected static puncture resistance obviously. [Copyright &y& Elsevier]

In this study, high resilience polyester fibers and low melting point polyester (LMPET) fibers are blended at varying ratios in order to form buffering composite nonwoven fabrics. Next, the employment of hot pressing enables the combination of the fabrics and elastic polymer films. The mechanical and buffering properties of the composites are evaluated in terms of the blending ratio and the thickness of the composites. As per the interface observation and the results of the peel test, the nonwoven fabrics and polymer films are firmly bonded. The tensile test results indicate that when there is more content of LMPET fibers, the reinforcement to the composites is greater. Conversely, the puncture test results indicate that the LMPET‐fiber‐free composites possess 1.4 times higher puncture resistance. Based on the results of the hammer rebound and compression recovery tests, a greater thickness provides the composites with better buffering efficacy. [ABSTRACT FROM AUTHOR]

Removal of organic solvents and heavy metals in effluents is of great significance to environmental pollution control and ecological civilization construction. pH-responsive materials have unique advantages in treating complicated oily wastewater. In this work, an intelligent pH-responsive nonwoven fabric with excellent reversible wettability was prepared. The pH-sensitive polymer was synthesized by free radical polymerization (FRP) technique, then dipped with SiO 2 on PP fabric. The particular molecular structure of poly (dimethylaminoethyl methacrylate) (PDMAEMA) enabled the fabric surface to switch wettability rapidly between hydrophilic/underwater oleophobic and oleophobic/hydrophobic under pH stimulus and exhibit controllable selective separation of various oil/water mixtures. Furthermore, the fabric removed Pb2+ efficiently under a wide pH range. The experimetal results showed that the separation flux reached 19,229 ± 1656.43 L-h−1-m−2 for water and 19,342 ± 1796.77 L-m−2-h−1 for n-hexane. Besides, the obtained fabric effectively realized the separation and collection process of complex ternary mixtures. The fabric removed Pb2+ in solutions with efficiency up to 90.83%. After immersing in acid and alkali solutions for 24 h, no significant damage to the surface wettability. This economical and intelligent fabric is able to meet the different separation purposes of industrial wastewaters with complex compositions. • A polymer coating with pH responsive property was prepared by using non-toxic and biocompatible monomers. • The pHR-PP could convert surface wettability from hydrophilic/oleophobic to hydrophobic/oleophilic under the stimulation of pH. • The pHR-PP could simultaneously adsorb heavy metal ions and realized heavy oil/water/light oil ternary mixture separation. • The pHR-PP possess good reusability and stability. [ABSTRACT FROM AUTHOR]

• A bioinspired worm-like thermoelectric fabric is fabricated by low-temperature interfacial polymerization. • The Seebeck coefficient of the fabrics reaches as high as 16.15 μV K−1 at 30 °C temperature difference. • The electrical and mechanical performances of the as-prepared fabrics negligibly decreased after bending and ultrasonic test. • The flexible coated fabric can be applied to thermoelectric generator and functional textiles. Inspired by worm morphology, this study report a low-cost and facile synthesis approach to construct a worm-like P-type flexible thermoelectric material—poly(3,4-ethylene dioxythiophene):p-toluenesulfonic acid (PEDOT:Tos) coated polypropylene (PP) nonwoven fabrics via low-temperature interfacial polymerization. This as-prepared thermoelectric fabric made of fibers with a core-shell structure has an electrical conductivity of 2.19 S/cm and the Seebeck coefficient of 16.15 μV K−1 at a temperature difference of 30 °C. Furthermore, it presents good mechanical and washing stability by bending and ultrasonic test. A thermoelectric device designed of five pairs of thermoelectric material (p-type) and copper wire (n-type) generates 0.512 mV voltage at a temperature difference of 10 °C. This thermoelectric device has a prospect in the application of portable and interactive devices. This study proposes an easy way to manufacture bioinspired thermoelectric fabric with high thermoelectric performance and high potential applications, such as in wearable and flexible sensors. [ABSTRACT FROM AUTHOR]

• LPET and PP are combined to fabricate nonwoven fabric by needle punch and hot press to reinforcement. • Hydrophilic-underwater superoleophobic PNIPAM@PP/LPET nonwoven fabric is successfully fabricated. • The coated nonwoven fabrics displays a much higher critical mechanical property. • The as-prepared nonwoven fabrics exhibit ultra-high flux and oil/water separation efficiency. Oil/water separation has become an urgent issue in environmental protection. Superhydrophilic and underwater superoleophobic membrane is promising materials for effective oil/water separation. In this paper, a novel oil/water separation nonwoven fabric with robust tensile strength and hydrophilic-underwater superoleophobic is successfully fabricated. This nonwoven fabric using low melt point polyester (LPET) fibers with a unique sheath-core structure to incorporate thermal bonding as reinforcement. Moreover, poly(N-isopropylacrylamide) (PNIPAM) dip-coated is also employed to modify the nonwoven fabrics to acquire the hydrophilic-underwater superoleophobic properties. The mechanical property, microstructure, water and underwater oil contact angle, and oil/water separation properties of PP/LPET nonwoven fabrics are measured, examining the effects of LPET fiber ratio and PNIPAM concentration. The test results show that an improvement in the mechanical properties after increasing the LPET content. The coated of PNIPAM endows the nonwoven fabric with a low water contact angle of from 80 ° to 0 ° (within 8 s), and underwater superoleophobicity with a high oil contact angle of 150 °. This nonwoven fabric can effective separation oil/water mixture with high permeate flux (∼21850 L ∙ m−2 ∙ h−1) and high separation efficiency (∼99%), solely driven by gravity. This kind of nonwoven fabrics is suggested as a promising candidate for oil/water separation and water purification. [ABSTRACT FROM AUTHOR]

• The bioenvironmentally friendly Janus nonwoven medical covers by needle punch/ hot press bonding manufacturing and spray coating are combined with super hydrophilic polylactic acid (PLA)/low-melt polylactic acid (LMPLA) nonwoven inner layer and Short fluoroalkyl chain polymers and waterborne polyurethane outer layer that offers the excellent protective performance of inner-layer liquid absorption to prevent flowback and outer-layer liquid repellence. • Janus property is achieved by changes of spinning times of Short fluoroalkyl chain polymers and waterborne polyurethane solution. • Low-melt polylactic acid (LMPLA) fiber ratio affects microstructure, breathable, mechanical and abrasion performance. • Short fluoroalkyl chain polymers and waterborne polyurethane coating improves hydrophobic, mechanical tensile, and increases abrasion resistance by 2.5 times those of a previously reported PU coating. Medical product contamination is a seriously threatens patients' health. However, few studies on the protective properties of nonwoven medical covers have been conducted. This work aims to develop bioenvironmentally friendly novel Janus polylactic acid (PLA)/low melt polylactic acid (LMPLA) nonwoven medical covers with asymmetric wettability and excellent mechanical, and abrasion resistance while maintaining outstanding breathability performance. The Janus fabrics have a dual structure with hydrophilic PLA/LMPLA nonwoven fabrics and hydrophobic short fluoroalkyl chain polymers/polyurethane membranes. Janus textiles are prepared through needle punch/ hot press bonding manufacturing and spray coating. The subsequent nonwoven fabrics exhibit an outstanding wettability gradient that offers the excellent protective performance of inner-layer liquid absorption to prevent flowback and outer-layer liquid repellence. Furthermore, the coating increases the tensile strength and abrasion resistance (of the fabrics by 2.5 times those of a previously reported PU coating reported in published paper). This kind of nonwoven fabrics is suggested to be a promising candidate for medical covers and health supplies. [ABSTRACT FROM AUTHOR]

The rise of fast fashion results in excessive waste and the redundant clothes cause environmental pollution due to the fact that synthetic fibers cannot be decomposed. Therefore, the disposal to textile waste becomes a critical issue in all countries. On the other hand, the majority of studies related to personal protective equipment commonly used high modulus fibers and manufacturing processes to strengthen the protection. As a result, the body armor that retains a certain weight and lower satisfaction from comfort interferes with the mobility of the wearers. Featuring comfortable texture and ease of processing, nonwoven fabrics can also be adjustable to suit the protection requirements. In this study, recycled Kevlar® fibers, nylon fibers, and low-melting polyester (L-PET) fibers are manufactured into the surface layers. Next, the surface layers enclose high strength polyester fibers (i.e. the interlayers) to form a sandwich structure. The tensile strength test, tear strength test, and burst strength test are conducted to examine the sandwich-structured composites. Specifically, when the content of L-PET fibers is 300 g/m2 and the needle punch depth is 15m, the composites exhibit optimal burst strength being 1957N and the optimal tensile strength being 425N, which demonstrates good mechanical performances. Proven by the test results, the recycled fibers still preserve their original high mechanical properties despite the finishing process, which helps to achieve the goal of reclamation without causing unnecessary pollution, and are a good candidate to the production of personal protective gear. Image 1 [ABSTRACT FROM AUTHOR]