Polypropylene Nonwoven Fabrics Research Articles

Functional assessment of biodegradable cotton nonwoven substrates permeated with spatial insect repellants for disposable applications

Arboviral diseases and malaria transmitted by mosquitoes are major health concerns worldwide responsible for millions of deaths annually. Spatial repellents have been used as preventative measures via direct application to the skin or disposable devices worn outside of clothing. Naturally derived, plant-based repellents are safe, effective alternatives to synthetic repellents and may be applied to disposable substrates including adhesive patches. Many disposables are composed of synthetic petrochemical-based polyester and polypropylene nonwoven fabrics, contributing to growing concern surrounding microplastic pollution. Sustainable and biodegradable substrates including those made from cotton are cost effective and environmentally friendly. Therefore, we explored the utilization of cotton-based substrates for the application of natural spatial and synthetic contact insect repellents. Cotton fibers used in the study were commercially available greige cotton, scoured and bleached greige cotton and reginned greige cotton motes, a value-added byproduct of the ginning process. Synthetic polyester and polypropylene were used for comparison. Thermogravimetric/derivative thermogravimetric analysis (TG/DTG) in combination with modulated differential scanning calorimetry (mDSC) were used to discern vaporization properties of repellents from the substrates. Retention times of repellents on the substrates were analyzed using a Fourier-transform infrared spectroscopy–focal plane array detector and compared with the TG/DTG and mDSC data. Mosquito landing assays confirmed the feasibility of using cotton-based substrates treated with plant-based spatial repellents as an effective and environmentally friendly alternative to synthetic materials.

Evaporation of droplets capable of bearing viruses airborne and on hydrophobic surfaces

Airborne and deposited water microdroplets can carry viruses including coronaviruses. The evaporation of microdroplets containing virus particles often leads to virus inactivation. Microdroplet evaporation involves various mechanisms such as diffusion, the Kelvin effect, infrared irradiation, and the role of solutes. For the evaporation of airborne water microdroplets, temperature and relative humidity of ambient air are important factors. However, for sessile droplets deposited on solid surfaces, wetting and porosity become important factors that control evaporation on regular, superhydrophobic, and photocatalytic surfaces. An experimental study of the effect of wetting properties and porosity on the evaporation rates on the polypropylene non-woven medical fabric was consistent with the theoretical models. Highly porous tile surfaces exhibited 2.2–4 times faster evaporation rates than nonporous surfaces.

Asymmetric wetting and antibacterial composite membrane obtained by spraying bacterial cellulose grafted with chitosan for sanitary products surface layers

The asymmetric wetting membranes have attracted intense attention in liquid directional transportation. However, it is a huge challenge to prepare surface layer membrane for sanitary products with antibacterial and asymmetric wettability by a simple method. Herein, the bacterial cellulose grafted with chitosan (BC-CS) was used as the hydrophilic agent to modify polypropylene nonwoven fabric (PPF) substrate via easy and effective one-sided layer-by-layer spraying to prepare the asymmetric wetting and antibacterial composite membrane (BC-CS/PPF). It showed that the BC-CS/PPF had good physical properties, which was attributed to the strong and uniform physical combination between nano-sized BC-CS and PPF. The sanitary products with BC-CS/PPF surface layer, denoted as BC-CS/PPF sanitary products, also had good absorption and anti-return property. The antibacterial test revealed that BC-CS had an excellent performance against S. aureus and E. coli in the simulated application environment. Moreover, the antibacterial performance was better than that of commercial sanitary products.

Comparative Study of Polypropylene Non-Woven Surgical Mask and Locally Manufactured Woven and Knitted Fabrics Facial Masks

The outbreak of coronavirus has led to an increase in the demand for facemasks globally. Unavailability of appropriate polypropylene non-woven fabrics face masks as a result of inadequate supply to satisfy the growing population has brought about the manufacturing of locally fabrics masks to augment or substitute standard medical class facemasks. The study aims at analyzing airflow of these locally manufactured fabrics to determine possible means of transmitting the virus as well as establish comfort of the user of these masks. Standard polypropylene non-woven, woven and knitted fabrics were considered for the study. Air permeability test was conducted on these fabrics using Frazier Air permeability tester. Depending on the property significant variation in the textile fabrics, polypropylene non-woven is widely accepted for facial masks. Nevertheless, this study illustrates that woven and knitted fabrics have more open structures, which allow a high rate of air penetration and so may require two or three layers to prevent antimicrobial or antiviral potential.

Bimetallic Ag-Cu nanoparticles anchored on polypropylene (PP) nonwoven fabrics: Superb catalytic efficiency and stability in 4-nitrophenol reduction

Herein, a convenient and environment-friendly grafting and reduction strategy was used to anchor bimetallic Ag-Cu nanoparticles on polypropylene (PP) fabrics. The as-prepared samples were characterized by various techniques including FE-SEM, XRD, EDX, XPS and FT-IR. The as-prepared sample exhibits excellent activity on the catalytic reduction of highly concentrated 4-NP, and the synergisticeffect between Ag and Cu nanoparticles was proved. The entire catalytic reduction was generally considered to obey pseudo-order kinetics, affording high conversion even after 15 successive recycles. These results showed that the PP based composite with Ag-Cu nanoparticles effectively provided superb catalytic efficiency and stability in 4-nitrophenol reduction, and the PP based composites were suitable in practical applications for the treatment of diverse waste water.

Facile Fabric Detoxification Treatment Method Using Microwave and Polyethyleneimine Against Nerve Gas Agents.

Generally, detoxification fabrics are defined as fabrics that remove or inhibit the production of toxic compounds, especially chemical warfare agents such as nerve gas agents. They are usually prepared using a complicated and time-consuming method. This study suggests a facile treatment method for preparing detoxification fabrics against nerve gas agents using polyethyleneimine and microwave curing. The detoxification properties of polyethyleneimine and microwave-treated polypropylene nonwoven fabric were evaluated using diisopropylfluoro-phosphate, which is a nerve agent simulant. The treated polypropylene fabric decontaminated 53.6% of diisopropylfluorophosphate (DFP) in 2 h at 32 °C, and the half-life of DFP on the surface of the treated fabric was 122 min. The result indicates that the treated fabric can act as a basic organocatalyst for the DFP hydrolysis and has a shorter half-life owing to the large number of amine groups. Therefore, the facile treatment method has the potential for use in the preparation of detoxification fabrics.

Graphene oxide-based rechargeable respiratory masks.

Respiratory masks having similar standards of ‘N95’, defined by the US National Institute for Occupational Safety and Health, will be highly sought after, post the current COVID-19 pandemic. Here, such a low-cost (∼$1/mask) mask design having electrostatic rechargeability and filtration efficiency of >95% with a quality factor of ∼20 kPa−1 is demonstrated. This filtration efficacy is for particles of size 300 nm. The tri-layer mask, named PPDFGO tri, contains nylon, modified polypropylene (PPY), and cotton nonwoven fabrics as three layers. The melt-spun PPY, available in a conventional N95 mask, modified with graphene oxide and polyvinylidene fluoride mixture containing paste using a simple solution casting method acts as active filtration layer. The efficacy of this tri-layer system toward triboelectric rechargeability using small mechanical agitations is demonstrated here. These triboelectric nanogenerator (TENG)-assisted membranes have high electrostatic charge retention capacity (∼1 nC/cm2 after 5 days in ambient condition) and high rechargeability even in very humid conditions (>80% RH). A simple but robust permeability measurement set up is also constructed to test these TENG-based membranes, where a flow rate of 30–35 L/min is maintained during the testing. Such a simple modification to the existing mask designs enabling their rechargeability via external mechanical disturbances, with enhanced usability for single use as well as for reuse with decontantamination, will be highly beneficial in the realm of indispensable personal protective equipment.

Copper nanoparticle decorated non-woven polypropylene fabrics with durable superhydrophobicity and conductivity

In this study, a facile method was prepared to fabricate highly flexible, conductive and superhydrophobic polymer fabrics. Copper nanoparticles (CuNPs) were decorated on polypropylene fabrics using a simple spraying method and superhydrophobicity was obtained after vacuum drying for 4 h without any surface modifier. Accumulation of CuNPs constituted coral-like rough micro-nano structures, forming a stable Cassie model and endowing the surface with dense charge transport pathways, thus resulting in excellent superhydrophobicity (water contact angle ∼159°, sliding angle ∼2.3°) and conductivity (sheet resistance ∼0.92 Ω sq−1). The fabrics displayed superior waterproof and self-cleaning properties, as well as great sustainability in the water. Additionally, the superhydrophobicity and conductivity can be almost maintained after heat treatment, wear testing, water droplet impinging, weak alkali/acid treatment and repeated bending-kneading tests. These superhydrophobic and conductive fabrics that are free from moisture and pollution can be a reliable candidate to solve the water-penetration issue in the rapid development of flexible electronics.

Investigation of electret and filtering properties of polypropylene-based nonwoven fabrics and its composites with 2 vol% of silicon dioxide inclusions

The electret characteristics of polypropylene (PP) nonwoven fabrics processed by melt-blowing and its composites with 2 vol% of silicon dioxide (SiO 2 ) are studied in this work. The surface potential V e , effective surface charge density a ef and electric field strengths E as well as their filtration efficiency are reported. Improvement of electret properties of PP filled with SiO 2 in comparison with the samples without filler is observed. It is seen that PP samples poled in a corona discharge show lower filtration rate than the non-poled ones. The electret nonwoven fabrics with improved filtration characteristics are obtained on the basis of PP with SiO 2 inclusions.

Worm-Like PEDOT:Tos coated polypropylene fabrics via low-temperature interfacial polymerization for high-efficiency thermoelectric textile

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.

An Advanced Dual‐Function MnO2‐Fabric Air Filter Combining Catalytic Oxidation of Formaldehyde and High‐Efficiency Fine Particulate Matter Removal

AbstractComprehensive treatment of indoor contaminants such as volatile organic compounds (VOCs) and fine particulate matter (PM2.5) using transition metal oxide catalysts or functional fibrous filters has gained substantial attention recently. However, coupling VOC oxidation catalysts into high‐performance filter systems remains a challenge. Herein, an overall solution to strongly bind manganese dioxide (MnO2) nanocrystals onto polypropylene (PP) nonwoven fabrics is provided. For the first time, uniform heterogeneous nucleation and growth of MnO2 onto PP nonwoven fabrics using intermediate inorganic nucleation films, including Al2O3, TiO2, and ZnO, formed conformally on the fabrics via atomic layer deposition (ALD) are demonstrated. How different ALD thin films influence the crystallinity, morphology, surface area, and surface oxygen species of the MnO2 grown ALD‐coated PP fibers is further investigated. In addition to uniformity and integrity, ZnO thin films give rise to MnO2 crystals with the largest fraction of available surface oxygen, enabling 99.5% catalytic oxidation of formaldehyde within 60 min. Moreover, the metal oxide filters provide excellent PM removal efficiencies (ePM), achieving ePM2.5 90% and ePM10 98%, respectively, making the approach an outstanding method to produce fully dual‐functional filtration media.

Intumescent flame retardant finishing for polypropylene nonwoven fabric

This work reports our recent efforts on improving the fire safety of nonwoven polypropylene fabric by increasing surface polarity followed by a conventional finishing. The fabric was firstly surface treated in a surfactant solution containing cetyltrimethylammonium chloride under ultrasonic to increase the hydrophilicity, and then was treated by a pad-dry process with a water solution of ammonium polyphosphate and pentaerythritol. The contact angle of polypropylene fabric treated with 0.2% cetyltrimethylammonium chloride was decreased to 71° from 130° of the control sample. The flammability was evaluated by limiting oxygen index, vertical flammability test, and cone calorimetry test. The limiting oxygen index value was increased to 23.5% from 18.1%, the peak heat release rate was decreased to 159.1 from 292.5 kW/m2, and the melt dripping was completely eliminated by the finishing treatment. Thermogravimetric analysis showed that treated polypropylene fabric samples had higher thermal stability and formed more char residue in high temperature range (above 450 °C) than the control polypropylene sample. The char morphology observation by scanning electron microscopy demonstrated that the treated fabric sample formed continuous char structure without voids, which effectively isolated underlying polypropylene fabric materials from fire and oxygen. It is proposed that decomposition compounds from both cetyltrimethylammonium chloride and ammonium polyphosphate catch free radicals in the gas phase, and the presence of ammonium polyphosphate and pentaerythritol promote char formation in the condensed phase during the burning process of polypropylene fabric.

Effects of Different Roller Profiles on the Microstructure and Peel Strength of the Ultrasonic Welding Joints of Nonwoven Fabrics

Nonwoven fabrics are widely used in the textile manufacturing industry due to their advanced characteristics, such as their soft, water-repellent, recycle, ecological, and resilient functions. Nowadays, one of the innovated technologies applied to bond nonwoven fabrics is the ultrasonic welding method, due to the advantages afforded by its clean, fast, and reliable approach. In this work, isotactic polypropylene (PP) nonwoven fabrics were bonded by a continuous ultrasonic welding process. In order to consider the influence of the roller on the formation of welding joints and their mechanical properties, different roller profiles were designed, fabricated, and tested. Eight types of roller profiles corresponding to No. 1–No. 8 in the experiments were divided into four groups. After bonding, the microstructure in a typical case (i.e., No. 1) was captured by scanning electron microscopy (SEM) to examine the formation of the welding joints. Additionally, the load and the peel strength of the welding joints of all eight roller profiles were analyzed. The results showed that no welding defects, such as cracks or blowholes, were visible in the melted zone. The load depended on the area ratio(s) of the welding area (S0) to the cycling area (S1). Furthermore, it was found out that the peel strength of the welding joints with brick structures were higher than the peel strength in the case of solid line structures.

Using antibacterial fibers and metallic wires to make woven fabrics used as smart diapers

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.

Development of Anti-Bacterial and Anti-Viral Nonwoven Surgical Masks for Medical Applications

This article aims to investigate the development of surgical masks for medical applications by incorporating biocidal silver nanoparticles. Medical masks were developed in three layers of a nonwoven fabric, where the outer and inner layers were made of a spun-bond polypropylene nonwoven fabric and the middle layer con­sisted of a melt-blown nonwoven polypropylene fabric. In this study, silver nanoparticles in the concentrations of 1–5% were applied to masks with the pad-dry-cure method. The samples were cured at room temperature and subsequently examined for antimicrobial properties. Scanning electron microscopy, energy dispersive spectroscopy and Fourier transform infrared spectroscopy were used to investigate the morphological charac­teristics and chemical composition of the samples. Microbial cleanliness, bacterial filtration efficiency, antiviral effect and breathability tests were performed according to standard test protocols. The results revealed that the application of silver nanoparticles to a three-layer mask rendered the end product with outstanding anti­microbial and antiviral properties with poor breathability (air permeability) results.

Novel antimicrobial nanocomposite based on polypropylene non-woven fabric, biopolymer alginate and copper oxides nanoparticles

The objective of this study was to develop novel antimicrobial nanocomposite material based on polypropylene (PP) non-woven fabric, biopolymer alginate and copper oxides nanoparticles. In order to introduce polar groups onto the surface of PP fibers necessary for binding of alginate, non-woven fabric was activated by corona discharge. Carboxylate groups of alginate were further utilized for binding of Cu2+-ions which were reduced with sodium borohydride as a conventional and ascorbic acid as a green reducing agent. Characteristic morphological and chemical changes induced by corona activation and alginate impregnation were confirmed by FTIR, XPS and FESEM analyses. AAS measurements showed that the amounts of generated nanoparticles depend on applied reducing agent and the concentration of precursor salt. XPS analysis suggested that nanoparticles were mixture of copper (I) and (II) oxides. XPS depth profiling gave an exceptional insight into chemical changes within the thin layer on the fiber surface and formation of certain interfaces induced by each treatment. All fabricated nanocomposites provided excellent antimicrobial activity against Gram-negative bacteria E. coli, Gram-positive bacteria S. aureus and yeast C. albicans. The cytotoxicity assay indicated that maximum amount of Cu2+-ions released from synthetized nanocomposite within 24 h was not cytotoxic to human keratinocyte (HaCaT) cells.

Superabsorbent Fibers for Comfortable Disposable Medical Protective Clothing.

Disposable medical protective clothing for 2019-nCoV mainly consists of stacked layers with nanopore films, polymer coated nonwoven fabrics and melt-blown nonwoven fabrics against anti-microbial and anti-liquid penetration. However, such structures lack moisture permeability and breathability leading to an uncomfortable, stuffy wearing experience. Here, we propose a novel medical protective clothing material with a superabsorbent layer to enhance moisture absorption. Poly(acrylic acid-co-acrylamide)/polyvinyl alcohol superabsorbent fibers (PAAAM/PVA fibers) were prepared via wet spinning. And the superabsorbent composite layer was stacked from PAAAM/PVA fibers, bamboo pulp fibers (BPF) and ethylene-propylene side by side fibers (ESF). The novel disposable medical protective composite fabric was obtained through gluing the superabsorbent layer to the inner surface of strong antistatic polypropylene nonwoven fabric. The resultant composite fabric possesses excellent absorption and retention capacity for sweat, up to 12.3 g/g and 63.8%, and a maximum hygroscopic rate of 1.04 g/h, higher than that of the conventional material (only 0.53 g/h). The moisture permeability of the novel material reached 12,638.5 g/(m2 d), which was 307.6% of the conventional material. The novel material can effectively reduce the humidity inside the protective clothing and significantly improve the comfort of medical staff.

Preparation and Application of Waterproof Polypropylene Nonwoven Fabrics for Grape Bagging

Bags of nonwoven fabrics with good air or water permeability are widely used in fruit agriculture due to their porosity. However, vegetables or fruit in bags often rot, a problem caused by the water permeability of the bags in high-moisture environments. Therefore, to improve the water repellency of polypropylene (PP) nonwoven fabric bags for fruit, a water-repellent treatment was applied by the surface deposition of a film composed of a water-repellent agent and a crosslinking agent. The effect of the waterproof bags made of PP spun-bonded nonwoven fabric on the grape growth microenvironment was investigated. This study provided technical inspiration for the development of related plant protection products using nonwoven engineered after-treatments.

Rapid adsorption of thin oil slick by modified polypropylene adsorption materials based on hydrophilic induction and hydrophobic capture

Residues oil from oil slick treatment on the water surface cause chronic damage to the environment. These thin oil slicks were labeled with fluorescent. Adsorption characteristics of the modified polypropylene (PP) non-woven fabric PP-GMA-OA/SS were studied. The introduction of hydrophilic groups on the surface of oleophilic materials can accelerate the adsorption of thin oil slicks and produces two strengthening effects. Hydrophilicity is used to induce water molecules to carry oil slicks approach to the fabrics. Hydrophobicity of the fabric is used to quickly capture the oil. Through a method of fluorescence image processing, thin oil slicks were quantified based on integrated optical density (IOD) values. The method verified the rapid adsorption performance of modified PP non-woven fabrics on residual oil slicks based on hydrophilic induction and hydrophobic capture. The material has considerable adsorption capacity and is economical as a supplement material to thin oil slick adsorption.

Synthesis of Fibrous Metal Adsorbent with a Piperazinyl-Dithiocarbamate Group by Radiation-Induced Grafting and Its Performance.

A fibrous grafted metal adsorbent with a piperazinyl-dithiocarbamate (PZ-DTC) group was synthesized by radiation-induced emulsion grafting of glycidyl methacrylate onto a polyethylene-coated polypropylene nonwoven fabric (PE/PP-NF) and subsequent three-step chemical modifications consisting of amination with N-(tert-butoxycarbonyl)piperazine (N-Boc-piperazine, NBPZ), deprotection of the Boc group with HCl, and dithiocarbamation with carbon disulfide (CS2). By using the NBPZ reagent in the amination step, the self-cross-linking of piperazine (PZ) could be completely suppressed, unlike using the PZ reagent. Consequently, the PZ-DTC group density of the fibrous grafted metal adsorbent synthesized through NBPZ attained 2.122 mmol-PZ-DTC/g-adsorbent, which was approximately 6 times higher than that of the metal adsorbent synthesized through PZ. The fibrous grafted metal adsorbent with the PZ-DTC group selectively adsorbed heavy metal ions over light metal ions. Furthermore, it exhibited high adsorption capacity, particularly for Cu2+. The Cu2+ adsorption capacity was determined to be 1.903 mmol-Cu2+/g-adsorbent by a batchwise adsorption test using a single-metal-ion aqueous solution at pH 6. The order of metal ion selectivity of the fibrous grafted metal adsorbent with the PZ-DTC group was Na+ < Mg2+, Ca2+, Co2+, Cd2+ < Pb2+ ≪ Cu2+, and Co2+ ≈ Ni2+ < Zn2+ ≪ Cu2+. In addition, the fibrous grafted metal adsorbent with the PZ-DTC group did not lose its metal adsorption function even under highly alkaline conditions (pH 15). It could recover Cu2+ efficiently and selectively from a high-concentration Na+ aqueous solution at this pH. The Cu2+ adsorption capacity of the fibrous grafted metal adsorbent with the PZ-DTC group was 0.754 mmol-Cu2+/g-adsorbent under a highly alkaline condition, a 10 M NaOH aqueous solution at pH 15. This value was approximately 2.4 times higher than that of the other grafted adsorbent with an amine-type functional group.