Melt Blowing Technique Research Articles

Analysis of the oscillations induced by a supersonic jet applied to produce nanofibers

High-performance fibers are key components for enhancing the mechanical properties of composite materials. The development of high strength nanofibers augurs the production of new nano-composites with outstanding features. However, the robust production of continuous glass nanofibers that can be feasible processed for efficiently manufacturing nanocomposites is still challenging. Recently, Cofiblas (Continuous Fiberizing by Laser melting and Supersonic dragging) was demonstrated as a technique capable of producing continuous glass nanofibers with unlimited length. Cofiblas process has some similarities with the widely known melt blowing technique for the production of polymeric fibers. In both techniques, the design of the gas nozzle is key to ensure the feasibility of the process since the turbulences of the gas jet may induce strong whipping of the filament.This paper gives novel experimental evidences on the correlation of the supersonic gas jet instabilities with the oscillation of the filament in the melt-blowing and Cofiblas processes, relating these oscillations with the presence of shock waves and unsteadiness in the flow, and gives valuable insight into the use of supersonic jets in the melt blowing process as an effective approach for the formation of nanofibers. A thin 3D-axisymmetric model in OpenFOAM® was put to test by comparing the performance of different solvers which were validated by flow visualization of the exit jet using digital holography (DH). In order to perform a realistic and thorough validation, we simulated the optical measurements of the flow from the CFD simulations of the mass density by Abel transform and numerical differentiation. The application of digital holography as the flow visualization technique makes possible both a precise validation of the density maps obtained from the Abel transformation of the 2D-alike results, and the analysis of the shockwave pattern in the air jet. Conversely, the numerical reconstruction of time-averaged holograms is employed to detect unsteadiness in the flow and to analyze the fiber oscillation, which is essential to assess the stability of the process. Lastly, the analysis and comparison of the vibration of the filament using the basic design and the optimized nozzle demonstrates a clear influence of the shock waves and flow unsteadiness in the stability of the filament.

Development of (TiO2-ZnO)/LDPE based active nanocomposite films and detection of migration to minced beef during storage using response surface methodology

In the current research, titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles using ethylene ethyl acrylate as compatibilizer are incorporated into low-density polyethylene (LDPE) to generate active nanocomposite films (ANFs) using melt blowing technique. The film properties such as colour, thickness, mechanical and thermal properties, surface morphology, and molecular composition were analyzed. Subsequently, minced beef samples were packed with ANFs, and migration was determined in 7-days storage period at 1 °C, 7 °C, and −18 0C. The migration characteristics were analyzed using inductively coupled plasma mass spectrometry (ICP-MS) at these 3 different temperature applications. The SEM results indicated that metal oxides had a substantially homogenous distribution in the polymer matrix, but agglomerates were formed in some regions. The Ti and Zn nanoparticles migrated to minced beef were significantly affected by the independent variables. The amounts of Ti and Zn migrated into minced beef samples ranged from 21.37 to 48.15 ppm and 11.01 and 52.74 ppm, respectively. In general, migration from Ti nanoparticles was greater compared to Zn nanoparticles. As a result, it has been demonstrated that TiO2 and ZnO nanoparticles are good alternatives to functionalizing food packaging film.

Binary structured polypropylene-/propylene-based elastomer fibrous membranes with enhanced flexibility

Polypropylene (PP) fibrous membranes are widely used in medical and healthcare due to its sustainability. However, pristine PP fibrous membranes show poor flexibility, which limits their advanced functional application in medical and healthcare. Therefore, to improve the flexibility of PP fibrous membranes, propylene-based elastomer (PBE), a copolymer compatible with PP, was introduced by using the melt blowing technique in this study. The SEM images show that the PP/PBE fibrous membrane samples expressed a binary structured network morphology consisting of fibers with a diameter distribution ranging from 0.4 to 15 µm. With an increase in PBE mass ratio from 15 to 80 wt%, the frequency of fibers with a diameter <3 µm increased from 48.6 to 61.2%, thus making the elastic recovery rate in the machine direction (MD) increase from 62.9 to 80.3% and softness values increase from 15.88 to 54.31. Meanwhile, air permeability increased from 856 to 2257 m3/m2 · h as the mass per unit area of the samples decreased from 129.9 to 40.1 g/m2. This work provides an alternate method for producing flexible fibrous membranes that have potential for application in items such as surgical gown cuffs, bandages, and face mask ear loops.

Fluffy Polypropylene–Polyethylene glycol fabrics with branched micro- and nanofibrous structures for rapid liquid transport

A high liquid-transportation capability is required for high-performance moisture-functional wound-dressing fabrics. However, simultaneously accelerating liquid wetting and penetration aspects remains challenging. Herein, we fabricated a fluffy polypropylene–polyethylene glycol (PP-PEG) fabric with branched micro- and nanofiber via an environmentally friendly and cost-effective melt-blowing technique. The introduction of incompatible PEG reduced the viscosity of the PP melt and decreased the dimension of fibers; thus, a branched micro- and nanofibrous structure was obtained. By incorporating the amount of 15 wt% PEG, the water content of the outer face increased from 70.3% to 270.6%. A fluffy structure in the fabric's thickness direction was achieved by tailoring the die-to-collector distance (DCD) during the melt-blowing process. The porosity increased from 87.1% to 90.1% with the DCD increased from 10 cm to 30 cm, which achieved a vertical penetration velocity of 7.02 cm/s at the water head of 90 mm. Moreover, micro- and nanofibrous morphology with the excellent mechanical properties and fine hydrolytic stability could enhance the water retention capacity that maintain the humidity of a microenvironment. This branched fluffy fabric with fast water-transportation capability is expected to be used in hygienic and medical fabric.

Melt blown polypropylene nanofiber template for homogenous pore channels monoliths

Monoliths are an important technology for filtration, liquid chromatography, and protein purification. A template commonly uses to produce porous monolith. However, it is a challenge to produce a monolith with a homogenous porous structure due to the arrangements of pores within the monolith are often uneven and sometimes closed, causing pressure to accumulate and increase within the monolith which reduce the efficiency of the monoliths. Therefore, an appropriate template is needed to produce a monolith with homogenous porous structure. Nanofiber is a potential alternative as a template due to its high porosity and interconnectivity. Therefore, this research aimed to investigate the potential of polypropylene melt blown nanofiber fabricated at various operating condition to fabricate monolith by assessing the monolith morphology. Nanofibers templates were produced using a melt blowing technique at various motor speeds, air pressures, and die-to-collector distance (DCD) between 30 and 50 Hz, 0.30 and 0.50 Mpa, and 20 and 50 cm respectively, design by Response Surface Methodology. The nanofibers were characterized for its morphology and melting point using scanning electron microscope (SEM) and molten point analysis instrument respectively. The findings show that the polypropylene nanofiber diameter was in the range of 3.58 to 11.00 x 103 nm. Meanwhile, melting point obtained were in the range of 121.0 to 128.8 °C. Subsequently macropores monoliths were successfully fabricated at 0.45 Mpa air pressure, 40 Hz motor speed and 60.23 cm die-to-collector distance. It can be concluded that, melt blown polypropylene nanofiber can be potentially applied as a template for monolith fabrication.

Synthesis of GMA/EDMA Uniform Pores Monolith Using Melt blown Polypropylene Nanofibers Templates

Glycidyl methacrylate / ethyl dimethacrylate (GMA/ EDMA) monoliths consisting of pores induced by polypropylene nanofibers (PPNF) were developed. For creating these pores, templating technique was used where the PPNF act as a template. The PPNF were fabricated using a melt blowing technique at various process operations of polymer flowrate, air pressure and die-to-collector distance at ranges of 15 to 30 Hz, 0.15 to 0.3 MPa and 0.20 to 0.6 m respectively designed using a response surface methodology (RSM). Subsequently, a monolith solution was synthesis using the polymerization of GMA and EDMA, with azobisisobutyronitrile (AIBN) as initiator and cyclohexanol as porogen. The PPNF and GMA/ EDMA monoliths were characterized using SEM and melting point instrument. The findings show, PPNF fiber diameter and melting points were in the range of 5 to 14 x 103 nm and 120 to 130 °C respectively. RSM analysis suggests that air pressure and die-to-collector distance could be an important factor for PPNF final diameter. Morphology studies demonstrate that GMA/ EDMA monolith have been successfully acquired mesoporous structure and creating uniform pores by PPNF template produce at 22.5 Hz, 0.22 MPa and 0.40 m. As a conclusion, the PPNF can be proposed as a template to prepare monolith having uniform pores.

MELT BLOWING PROCESS CONDITIONS FOR NANOFIBERS OF POLYMERS FOR OIL-WATER SEPARATION IN MARINE OIL SPILLS CLEAN-UP APPLICATIONS: A SHORT REVIEW

The development of oil and gas industries has resulted in environmental issues, such as oil pollution. Oil pollution in a marine environment, poses significant threats to not only coastal marine life, but also to the social economic activities of community living in the nearby areas. The spreading of the oil could be controlled efficiently using sorbents such as nanofiber, due to its high specific surface area, high porosity, small diameter, and small pore sizes properties. Common approach to produce nanofiber is by using electrospinning technique however, this technique has low productivity and requires a post treatment for solvent removal. However, a melt blowing technique is an alternative to electrospinning as it is highly productive and does not require any solvent. The mass production of nanofiber fulfils the demand of the material during an oil spill clean-up operation. Therefore, this review discusses the influence of melt blowing process conditions such as die, polymer, air and collector, on the properties of nanofiber targeted for oil-water separation for the application of oil spill clean-up.

Facile fabrication of triboelectric nanogenerator based on low-cost thermoplastic polymeric fabrics for large-area energy harvesting and self-powered sensing

Triboelectric nanogenerator (TENG) which can work as novel power provider and self-powered sensor has been in rapid development in recent years. Unfortunately, fabricating large-area TENG through a low-cost, facile, continuous and environmentally friendly method still remains a challenge but highly desired. Herein, via melt blowing technique, a low-cost, durable and large-area fabric-based triboelectric nanogenerator (FB-TENG) was fabricated. Such FB-TENG comprises of polypropylene non-woven fabrics (PP-NWF), commercial polyamide 66 fabrics (PA-66-F) and conductive fabrics (Ni@fabrics). Furthermore, it has remarkable stability even when working for a long time, showing multifunctional applications. For example, on the one hand, as a power provider, FB-TENG can drive miniature electronic products. On the other hand, as a self-powered sensor with extremely short response time, FB-TENG can collect pedestrian volume and monitor pugilism training precisely. This work paves a new way for developing FB-TENG through a low-cost, facile, continuous and environmentally friendly method, showing potential applications including self-powered motion tracking, tactile sensing and remote wireless training monitoring system.

Study on Spinnability of PP/PU Blends and Preparation of PP/PU Bi-component Melt Blown Nonwovens

Melt blown polymer blends offers a good way to combine two polymers in the same fiber generating nonwovens with new and novel properties. In this study, polypropylene (PP) and polyurethane (PU) were blended to prepare PP/PU bicomponent melt blown nonwovens. The spinnability of PP/PU composites was investigated and PP/PU bi-component nonwovens with compositions of 95/5, 90/10, 80/20 and 70/30 were prepared by using the melt blowing technique. The melt blown fibers exhibited a ‘sea-island’ structure with PP as the continuous phase and PU as the dispersed phase. When the content of PU in the blend was above 40 %, PP/PU melt blown nonwovens could not be produced due to fiber breaking. For PP/PU (90/10) nonwovens, it was found that the average fiber diameter decreased with increasing die to collector (DCD) and elevated hot air pressure.

Fabrication of helical microfibers from melt blown polymer blends

ABSTRACTHelical fibers in micro/nanoscale resembling plant tendrils have been of increasing interest due to their unique characteristics. Fabrication of helical microfibers from polymer blends using melt blowing technique is reported in this study. An elastomeric and a stiff polymer are chosen as the raw materials, and a designed swirl‐die melt‐blowing device is used to prepare the microfibrous nonwovens. Focusing on the interfacial interaction between the polymer components induced by the polymer structure and intrinsic properties, airflow field characteristics, and processing parameters, we explore the effects of various parameters on helical fiber formation. Differential scanning calorimeter is employed to examine the rigidity of polymer chains, and the three‐dimensional airflow field simulation is carried out to reveal the airflow field characteristics. This work can provide a promising technique for producing stretchable microfibrous materials which have potential applications in field such as filtration materials and oil sorbents. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys.2018,56, 970–977

Research on a Nonwoven Fabric Made from Multi-Block Biodegradable Copolymer Based on l-Lactide, Glycolide, and Trimethylene Carbonate with Shape Memory.

The presented paper concerns scientific research on processing a poly(lactide-co-glycolide-co-trimethylene carbonate) copolymer (PLLAGLTMC) with thermally induced shape memory and a transition temperature around human body temperature. The material in the literature called terpolymer was used to produce smart, nonwoven fabric with the melt blowing technique. Bioresorbable and biocompatible terpolymers with shape memory have been investigated for its medical applications, such as cardiovascular stents. There are several research studies on shape memory in polymers, but this phenomenon has not been widely studied in textile products made from shape memory polymers (SMPs). The current research aims to explore the characteristics of the PLLAGLTMC nonwoven fabric in detail and the mechanism of its shape memory behavior. In this study, the nonwoven fabric was subjected to thermo-mechanical, morphological, and shape memory analysis. The thermo-mechanical and structural properties were investigated by means of differential scanning calorimetry, dynamic mechanical analysis, scanning electron microscopic examination, and mercury porosimetry measurements. Eventually, the gathered results confirmed that the nonwoven fabric possessed characteristics that classified it as a smart material with potential applications in medicine.

Elaboration of small‐diameter vascular prostheses—Selection of appropriate sterilisation method

ABSTRACTThe aim of study is the elaboration of semi‐biodegradable, multilayered tubular structures as substitutes for the reconstruction of small diameter vascular prostheses (<6 mm). The inert external layer of the prostheses will be fabricated via the melt electrospinning of poly (l‐lactide‐co‐glycolide) (PLGA). The middle layer will be constructed from polypropylene (PP); the first prototype will be produced via melt electrospinning and the second using the melt blowing technique. The general aim of this stage of the research is the selection of a sterilisation technique that is appropriate for semi‐biodegradable, multilayered tubular structures. For this purpose, single tubular structures created via the melt electrospinning of PLGA or PP and melt blown tubular structures of PP were elaborated. The influence of steam, ethylene‐oxide (EO), and radiation sterilisation techniques on the elaborated microstructure of tubular structures was analyzed during this study. The effect of each sterilisation technique was evaluated using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy/energy‐dispersive X‐ray spectroscopy analysis (SEM/EDS). The changes in average molecular weight (Mw) and crystallinity index (CI) of the PLGA tubular structures after EO and steam sterilisation were evaluated. The EO and steam sterilisation resulted in the complete destruction of PLGA tubular structures. Only the radiation sterilisation (accelerated electrons) did not influence on PLGA tubular structures morphology as well as thermal and chemical properties. FTIR and SEM/EDS analysis indicated that no changes in the chemical properties of PP tubular structures after each sterilisation occurred. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40812.

Melt blowing of ionic liquid-based cellulose solutions

The melt-blowing technique is usually used for thermoplastic resins, not for non-thermoplastic materials. In this study, nonwoven fabric was successfully obtained by a cellulose solution through melt-blowing technique. The solution was prepared by a twin-screw extruder after mixing cellulose pulp with 1-Allyl-3-methylimidazolium Chloride ([AMIM]Cl). Nonwoven fabric exhibited typical characteristics of those from melt-blown thermoplastic resins. Some aspects of meltblowing process are discussed, such as cellulose concentration, temperature of extrusion die and hot air pressure. In experimental range, to obtain nonwoven web, cellulose concentration was below 15 wt%. Temperature of extrusion die and hot air pressure had great influence on the fabric. With the increasing of temperature of extrusion die and hot air pressure, the fiber changed thin and the fiber web became better, while the fiber diameter became thicker after increasing the cellulose concentration. Elevating the temperature of extrusion die, the degree of polymerization decreased, and the quality of the fiber webs declined.

Aerobic treatment of industrial wastewaters by biofilters with fibrous polymeric biomass carrier

Processes of aerobic biological purification by pilot biofilters of chemical enterprise sewage (COD 14 g dm−3) and recirculating waters of atomic power station contaminated with oil products (10–270 mg dm−3) have been investigated. Fibrous materials were used as biomass carriers. These have been manufactured from thermoplastics (polyethylene, polypropylene, polyamide) by melt-blowing technique. New polymeric fibrous carriers (PFC) of optimized composition, structure and shape are superior to common carriers (claydite, porous ceramics, foamed polyurethane) by specific sorption capacity towards complex associations of microorganisms. In contrast to biofilters filled with claydite, those filled with PFC are characterized by accelerated transfer to stationary working regime, above 90% of biopurification efficiency of high-loaded industrial wastewaters and process stability at toxic actions of biomass, as well as reduced aero- and hydrodynamic resistance of the filtering biolayer. Prospects of improving the biofilter operation are discussed, in particular, by means of carrier modification: fiber filling with magnetic or electroconductive substances, adhesive fixation of adsorbents on the fibers, etc. Such PFC can be related to a promising generation of biosorbents and biomass carriers.