Melt Blowing Research Articles

Antibacterial nonwoven materials in medicine and healthcare.

Bacterial infection has always been a severe challenge for mankind. The use of antibacterial nonwoven materials provides a lot of convenience in daily life and clinical practice grammar revision, it has become an important solution to avoid bacterial infection in clinical and daily life. This review systematically examines the spin bonding, melt blown, hydroneedling and electrospinning methods of nonwoven fabrication materials, and summarizes the antibacterial nonwoven materials fabrication methods. Finally, the review discusses the applications of antibacterial nonwoven materials for medical protection, external medical and healthcare, external circulation medical care implantable medical and healthcare and intelligent protection and detection. This comprehensive overview aims to provide valuable insights for the advancement of antibacterial nonwoven materials in the domain of medicine and health care. In the future, antibacterial nonwoven materials are expected to evolve towards biodegradability, composite materials, functionalization, minimally invasive techniques, diversification, and intelligence, thereby holding immense potential in healthcare.

3D melt blowing of Elastollan thermoplastic polyurethane for tissue engineering applications: A pilot study

Scaffolds, in addition to being biocompatible, should possess structural and mechanical properties similar to the natural tissues they intend to replace. Many tissue engineering applications require porous 3D scaffolds characterized by unique microfibrous organization and mechanical anisotropy. Manufacturing process principles and process parameter-biomaterial interactions ultimately govern the properties that can be achieved in the scaffold. In this study, we investigate a recently developed nonwoven scaffold fabrication process, 3D melt blowing (3DMB), for processing Elastollan®, a thermoplastic polyurethane with basic mechanical properties suitable for musculoskeletal tissue engineering. The range of feasible processing parameters was screened and the effects of two sets of critical process parameters (fiber deposition offset and surface velocity of the collector) that produced contrasting scaffold morphologies were assessed. Results showed that scaffolds of Group B that were fabricated at the higher fiber deposition offset (90 %) and higher surface velocity of the collector (6 × 105 mm/min) possessed significantly smaller fiber diameter and higher porosity and degree of fiber alignment along the principal direction of collector rotation during 3DMB (all p < 0.05) compared to Group A scaffolds (fabricated at 50 % offset and 1 × 105 mm/min surface velocity). Although both groups possessed similar tensile stiffness, the elongation at failure was significantly different (p < 0.0001). The higher elongation at failure of Group B correlated with the higher degree of fiber alignment in these scaffolds. In contrast, the more isotropic fibrous organization of Group A contributed to their higher compressive stiffness (p = 0.004). The introduction of NaOH treatment to improve hydrophilicity of the scaffolds resulted in a significant reduction of tensile stiffness of Group A (p < 0.05) but not Group B. This treatment did not significantly affect the elongation at failure or compressive stiffness of both groups. With NaOH-treatment, both groups demonstrated good biocompatibility when seeded with fibroblast cells over 14 days. This study confirms the ability to fabricate via 3DMB, biocompatible, micro-fibrous, Elastollan scaffolds relevant for musculoskeletal tissue engineering.

Research on the Model of Interlayer Melt Blown Non-woven Materials Based on Regression Prediction

Research on the Model of Interlayer Melt Blown Non-woven Materials Based on Regression Prediction

Investigate the Processability of Biobased Thermoplastics Used in Nonwoven Fabrics.

The Covid-19 pandemic increased enormously the manufacturing and usage of face masks and other personal protective equipment (PPE), resulting in accumulation of plastic waste and, thus, causing universal environmental concerns. In addressing the issue of waste reduction and finding alternatives for fossil-based products, investigation of different biobased and biodegradable polymers plays a crucial role. This study examines the processability characteristics of three commonly used biobased polymers available in the market: biobased poly(lactic acid) (PLA), partly biobased and biodegradable poly(butylene succinate) (PBS), and biobased high-density poly(ethylene) (BioHDPE). The investigation combines substantial polymer analysis with subsequent processability trials in two different spunmelt processes, namely, meltblow (MB) and the Nanoval technology, aiming to reveal the differences and difficulties in the processing behavior and pointing out advantages and/or disadvantages of the respective polymer/technology combination. In general, the observed processability behavior and outcomes indicate that within the used processes PLA exhibits superior processability compared to PBS and BioHDPE. Both the meltblow and Nanoval processing of PLA demonstrated a consistent production of fibers and efficient uptake without any compromise on the throughput. In contrast, the processing of PBS using Nanoval required the utilization of significantly elevated temperatures, as indicated by a rheological study. Furthermore, the rheological evaluation revealed that the viscosity of BioHDPE was excessively elevated, rendering it unsuitable for effective processing by the Nanoval method. The microfibers in the PLA-based meltblown fabric had a higher surface area, explaining why the PLA fibers were able to function as a barrier and, thus, contribute to the mitigation of air permeability adjustable between 500 and 1000 l·s-1·m-2 and thus competitive or even superior to PP nonwovens of the same fiber diameter and base weight (1480 l·s-1·m-2). Overall, these results showed that PLA can be an alternative raw material for fossil-based nonwovens of PPE applying, especially, the meltblown technique.

A facial method for constructing superhydrophobic surface by one-step surface etching combined with melt blowing process

It is a challenge to prepare fluorine-free superhydrophobic surfaces by simple methods. In this work, a simple and effective method for constructing a superhydrophobic surface was developed by combining in situ nanofibrillating melt blowing processs and one-step surface etching. Firstly, the randomly stacked meltblown microfibers as microstructure transformed the wetting performance of the surface from hydrophilic to hydrophobic. Then, by tuning the etching time, the outmost nanofibrils within the microfibers were exposed to form nanostructure thereby achieving superhydrophobic performance with a contact angle of 153°. The superhydrophobicity of the as-prepared nonwoven was maintained after various harsh treatments, such as strong acid, strong alkaline, sandpaper abrasion, and ultrasonic washing, showing stable water repellency ability. In addition, the superhydrophobic nonwoven showed promising application in self-cleaning and oil–water separation. Thus, this work not only prepares a superhydrophobic surface but also proposes a new idea for designing a micro-nano hierarchical structure on the surface.

PVA/whey protein nanofiber-coated PP melt blown integrated with Pickering emulsion of citral stabilized for potential medical applications

As an antibacterial agent with pleasant fragrance, citral (CIT) indicates hydrophobic character, and therefore has low water solubility. In this study, Pickering emulsions were formed and polyvinyl alcohol (PVA)/whey protein hydrophilic nanofibers were coated on PP melt blown non-woven surfaces by electrospinning method. In this context, hydrophobic citral essential oil is stabilized with β-cyclodextrin (β-CD) in the electrospinning process. PVA and whey protein polymer blend were used as nanofiber matrixes. The morphological, physical, and thermal properties of the β-CD/citral complexes were investigated in PVA/whey protein nanofiber-coated PP non-wovens at various β-CD levels (1:2, 1:4 and 1:6). Furthermore, zone inhibition procedure was performed to evaluate antibacterial activity of the samples against Gram (+) (Staphylococcus aureus ATCC® 25923) and Gram (-) (Escherichia coli ATCC® 25922, and Pseudomonas aeruginosa ATCC® 27853) bacteria. The morphology of fibers showed that all obtained nanofiber-coated PP surfaces were in the range with 216 - 330 nm average fiber diameter. Fourier Transform Infrared (FT-IR) and thermal gravimetric analysis (TGA) thermograms revealed that citral were successfully integrated into the bio-based nanofibers. As the amount of citral increased (i.e., the β-CD/citral increased), the thermal resistance of bio-based nanofiber coated PP surfaces increased. Antibacterial activity indicated the citral-loaded nanofiber-coated PP surfaces were most effective against Escherichia coli, while none of the samples have antibacterial activity against Pseudomonas aeruginosa. Overall, the results displayed that the fabricated PVA/whey protein nanofiber-coated PP samples integrated with Pickering emulsion of citral stabilized have promising wound dressing applications.

Development of Particle Filters for Portable Air Purifiers by Combining Melt-Blown and Polytetrafluoroethylene to Improve Durability and Performance

Improving indoor air quality through the use of air purifiers has become a major focus, with emphasis on developing filters with high efficiency, high holding capacity, and low-pressure drop to improve the clean air delivery rate (CADR) for air purifiers. However, although most studies focused on developing media and evaluating their performance, few studies have reached the employment for a pleated filter. In this study, we newly synthesized flat media and pleated filters by combining polytetrafluoroethylene membrane (PT) and melt-blown (MB) materials (PM) and compared its initial performance to that of other air purifier filters (MB, glass fiber, and PT). Additionally, we analyzed how the performance changed after the particles were loaded. The initial efficiency of the PM filter showed a higher quality factor (QF) than the other filters. Furthermore, when more particles were loaded, the penetration of the PM did not change. These results demonstrate the potential of the PM. However, the CADR and submicron-sized (0.02–0.113 μm) CADR (sCADR) were highest for the MB filter due to the initial pressure drop. Therefore, additional improvements are required to apply the PM in air purifiers. However, the results suggest that the PM can be a new alternative for air purifier filters used in medical centers or facilities with vulnerable populations where a high-efficiency particle air (HEPA) filter must be used.

Porous Melt Blown Poly(butylene terephthalate) Fibers with High Ductility and High-Temperature Structural Stability.

In this study, porous poly(butylene terephthalate) (PBT) fibers were produced by melt blowing cocontinuous blends of PBT and polystyrene (PS) and selectively extracting the interconnected PS domains. Small amounts of hydroxyl terminated PS additives that can undergo transesterification with the ester units in PBT were added to stabilize the cocontinuous structure during melt processing. The resulting fibers are highly ductile and display fine porous structural features, which persist at temperatures over 150 °C. Single fiber tensile testing and electron microscopy are presented to demonstrate the role of rapid quenching and drawing of the melt blowing process in defining the fiber properties. The templated highly aligned pore structure, which is not easily produced in solvent-based fiber spinning methods, leads to remarkable mechanical properties of the porous fibers and overcomes the notoriously poor tensile properties common to other cellular materials like foams.

Hybrid processing of melt electrospinning/blowing for polypropylene/polyethylene glycol fiber fabrication with various diameter distribution

Many studies have been conducted to develop and optimize the manufacturing process of polymer fibers in various forms. In particular, many melt-spinning processes have been developed for the manufacture of nanofibers of polymer materials with excellent chemical resistance. In this study, we investigated the effects of various spinning conditions and their spinning behavior on the fiber manufacturing process and properties using a melt electrospinning/blowing process that combines conventional melt blowing and electrospinning. We also report a discontinuous spinning process that produces a web with a very wide diameter distribution from the nanoscale to the microscale with gradient fibers. They are generally compared with webs, which have a narrow diameter distribution. We believe that by using this process, it is possible to produce diameters of various distributions in one step. These results show remarkable potential for many applications in which gradient fibers are required.

Styrene-ethylene-butylene-styrene (SEBS) melt-blown fibers for oil spill remediation and oil barrier geotextiles

The distinctive oil gelation characteristics of styrene-ethylene-butylene-styrene (SEBS) thermoplastic elastomers were utilized for successful oil spill remediation with a range of different oils. Porous non-woven SEBS mat was fabricated via melt blown processing using a twin-screw extruder with customized blow die. After conducting rotational and capillary rheology investigations, a heightened melt-blowing temperature (300 °C) was applied to achieve an elevated melt flow index of SEBS for the melt-blowing process. Under optimized blowing parameters, a non-woven fabric was obtained consisting of fine fibers featuring an average fiber diameter of 20 μm. The material and oil absorption properties of the engineered SEBS fabric were compared to polypropylene (PP) nonwovens, a widely used material for oil spill mitigation that relies solely on adsorption and capillary forces to separate and immobilize spilled oil. SEBS nonwovens exhibited outstanding absorption and gelation properties for both crude petroleum and mineral transformer oil. Notably, SEBS demonstrated the ability to immobilize oil even under head pressure and at saturation, surpassing the capabilities of PP nonwovens (average fiber diameter 12 μm). This showcases a more efficient and cleaner method for remediating oil spills by effectively separating oil from water through absorption.

Microplastics and volatile organic compounds released from face masks after disinfection: Layers and materials differences

Effective disinfection methods are critical for ensuring the reusability of masks, yet these methods may inadvertently introduce health concerns associated with microplastics (MPs) and volatile organic compounds (VOCs). This study investigated the impact of ultraviolet germicidal irradiation (UVGI) and sodium hypochlorite (NaClO) bleaching on mask filter layers composed of four distinct materials. Our results revealed that UVGI induced more pronounced damage compared to bleaching, leading to the significant release of both MPs and VOCs. After UVGI treatment at conventional disinfection doses, meltblown (MB) fabrics released MPs reaching 864 ± 182 μg/g (92 ± 19 particles/g). For all filter layers, the quantity of released MPs followed the order: MB > HDPE>PU ≈ NW. These MPs were identified as degraded debris from the mask filter layers. The specific VOCs generated varied depending on the material composition. Non-woven (NW) and MB fabrics, both comprised of polypropylene, predominantly produced various branched aliphatic hydrocarbons and their derivative oxides. The cotton-like fabric, composed of high-density polyethylene, primarily emitted different linear aliphatic hydrocarbons and oxygenates. In contrast, the polyurethane filter layer of reusable masks released aromatic compounds, nitrogenous compounds, and their oxidation products. The formation of VOCs was primarily attributed to bond breakage and oxidative damage to the filter structure resulting from the disinfection process. In summary, as UVGI induced higher yields of MPs and VOCs compared to bleaching, the latter would be a safer option for mask disinfection.

Katmanlı ve bimodal nanolifli yapılarla filtrasyon performansının artırılması

Particulate matter (PM) must be removed from the air because it is a serious threat to human health. Micro and/or nanoporous nonwoven fabrics are commonly used to filter these particles. In our study, the filtration performances of nanofibrous mats, which were obtained by combining fibers produced by two different production methods in a layered and bimodal manner, were evaluated. Fibrous layers produced by the meltblown (MB) method were obtained with similar fiber diameters and different thicknesses by different feeding speeds. Bimodal structures obtained by adding fibers with an average diameter of 225 nanometers produced by the solution blowing (SB) method into fibers with an average diameter of around 800 nm obtained at 1, 5 and 10 rpm screw rotating/feeding speeds had higher filtration performance than the samples without SB nanofibers. Then, among the 4 samples with an average basis weight of 15 gsm, the sample MB only without (electro-blown nanofiber); the EB sample contains only EB nanofibers; the sample (L) containing 4 gsm EB nanofibers and the 4-layer sample (4L) containing 4 gsm EB nanofibers (138 nm) were compared. The 4L sample had the highest quality factor (0.0353) with a filtration efficiency of %96.01 and a pressure drop of 135 Pa. Although the filtration efficiency increased in all samples with the subsequent corona treatment, the highest value (99.34%) was obtained from the 4L sample.

Enhancing filtration performance of submicron particle filter media through bimodal structural design

AbstractDepth filtration is a widely utilized mechanism for submicron aerosol filtration using disposable filter cartridges and facemasks. The filter media should be carefully engineered to reach high filtration efficiency and dust‐loading capacity at the expense of a low‐pressure drop (ΔP). Filter media with bimodal fiber diameter distribution enhance particle capture by creating small pores with tiny fibers, while microfibers improve airflow, reduce ΔP, and increase the effective filter area for particle retention. In this study, bimodal filters were achieved through the homogeneous distribution or layered use of nanofibers and microfibers. The impact of the bimodal design was explored using fibrous mats produced through melt‐blowing, solution‐blowing, and electroblowing methods. Keeping the basis weight of filter samples at 30 gsm, using four‐layered filters (4L) improved air permeability compared to single‐layer samples. The 4L sample exhibited the highest performance, achieving 99.52% efficiency at 148 Pa. Moreover, replacing the melt‐blown layer with bimodal mats in the 4L design increased the filtration efficiency to 99.61% keeping ΔP nearly the same. The corona discharge treatment yielded the highest efficiency (99.99%) in the 4BML sample, even after 1 month the efficiency was maintained at 99.90%, highlighting the advantage of bimodal fiber distribution in electret filters.Highlights Four‐layered filter (4L) structures resulted in improved air permeability. Bimodal layer (BL) achieved by adding SB nanofibers into the melt blowing. BL in 4L structure increased the efficiency from 99.52% to 99.61%. Modified BL sample (4BML) provides the highest QF (0.044 Pa−1) after 1 month.

POSS(epoxy)8 reinforced poly (butylene adipate-co-terephthalate)/lignin biodegradable films: Fabrication, enhanced mechanical properties and UV aging resistance

To reduce the white pollution, the eco-friendly biodegradable poly (butylene adipate-co-terephthalate) (PBAT)-based films had attracted increasing interests worldwide. However, the high-cost of the PBAT had limited the large-scale development and application. In this work, 10 wt% low-cost lignin was introduced into the PBAT to prepare composite films by melt blending and blow molding, and the POSS(epoxy)8 was selected as the compatibilizer to improve the compatibility of PBAT and lignin. The maximum tensile strength and the nominal strain at break subsequently increased by 48.2 % and 21.4 % respectively, while the water vapor permeability enhanced by 9.9 %. Furthermore, the UV aging resistance of PBAT/lignin films were significantly improved, with only 1 wt% POSS(epoxy)8 content. This work provides an efficient strategy to foster the end-user confidence in the low-cost and eco-friendly biodegradable polymer materials with efficient performance.

Toxic effects of aging mask microplastics on E. coli and dynamic changes in extracellular polymeric matter

Contamination of disposable medical masks has become a growing problem globally in the wake of Covid-19 due to their widespread use and improper disposal. Three different mask layers, namely the outer layer, the meltblown (MB) filler layer and the inner layers release three different types of microplastics, whose physical and chemical properties change after prolonged environmental weathering. In this study, physical and chemical changes of mask microplastics before and after aging were characterized by different characterization techniques. The toxic effect and mechanism of aged mask microplastics on Escherichia coli (E. coli) were studied by measuring the growth inhibition of mask microplastics, the change in ATPase activity, the change in malondialdehyde content and reactive oxygen species production, and the release of the chemical composition of exopolymeric substances (EPS). The microplastics of the aged MB filter layer had the most significant inhibitory effect on E. coli growth, reaching 19.2 % after 36 h. Also, under the influence of mask microplastics, ATPase activity of E. coli was inhibited and a large amount of EPS was released. The chemical composition of EPS has also changed. This study proposed the possible toxicity mechanism of mask microplastics and the self-protection mechanism of E. coli, and provided a reference for future research on the toxic effects of mask microplastics on environmental organisms.

Numerical and Experimental Investigation of Thermal Insulation Property of Melt Blown Materials

Numerical and Experimental Investigation of Thermal Insulation Property of Melt Blown Materials

Preparation of antibacterial composite fiber membrane for air filtration with micro/nano structure

With the aggravation of environmental pollution and the worldwide epidemic of infectious diseases, there is a higher demand for air filtration materials to intercept fine particulate matter and capture biological pollutants. Polypropylene (PP)/polycarbonate (PC) blends were melt blown and electrospun with polytetrafluoroethylene (PTFE) on their surfaces. The PP/PC/PTFE membranes structure with micro-nanostructure was constructed through the melt-blown layer with micron structure and the electrospun layer with the nanostructure. Carboxymethyl chitosan (CMCS) was loaded onto the surface of the PP/PC melt-blown layer. The synergistic effect of micro-nanostructure and CMCS can effectively capture PM2.5 and make the composite membrane have excellent antibacterial performance. The inhibition rates of PP/PC/PTFE composite membrane loaded with 5% CMCS against Staphylococcus aureus and Escherichia coli reached 81.54% and 86.1%, respectively. The filtration efficiency of PP/PC/PTFE composite membrane loaded with 5% CMCS is close to 100% for 0.25 μm particles, and the average filtration efficiency for 0.200–4.596 μm and 0.200–2.500 μm particles is 97.31% and 97.27%, respectively. After washing and drying five times, the corresponding inhibition rate only lost 16.52% and 4.24%. The micro/nano structure composite membrane prepared in this study has good antibacterial performance, high filtration efficiency, good stability, and is an excellent antibacterial high efficiency air filter. It provides a new idea for the preparation of air filter fiber composites.

A Continuous Production Apparatus for a Frame-Type Melt-Blown Filter Cartridge with Various Properties and Geometry

Polypropylene (PP) melt-blown (MB) filter cartridges are widely used in many fields requiring water purification, such as households, the food industry, industrial processes, and recycled water filtration. While the demand for filters has gradually increased, the environmental requirements and conditions have become severe. The filters are easily deformed from higher liquid pressure during operation and setup and need to be replaced frequently. With the lifetime of filters shortened, manpower increases to replace filters. Hence, the inner structure of a PP melt-blown filter cartridge is supported by a frame structure to resist higher liquid pressure for enhancing filtration efficiency and lifetime. The filter, known as a “frame-type melt-blown filter cartridge”, does not affect the user’s application environment and equipment. This article focuses on developing continuous production equipment for frame-type melt-blown filter cartridges. The core technology of the equipment is the mechanism design for conveying frame tubes integrated with the MB process. The PP fiber is simultaneously melted and blown on the frame tube, and the frame tube needs to be pushed forward while rotating. This mechanism can independently control the fiber’s rotational speed and push speed. The rotational speed affects the surface density, fiber diameter, and porosity of the melt-blown filter cartridge, and the push speed affects the core diameter and weight of the melt-blown filter cartridge. In addition, there is a frame tube feeding device at the input end of the conveying equipment for continuously carrying the frame tube. Then, the finally formed melt-blown filter cartridges enter the cutting machine to trim a certain length to complete a frame-type melt-blown filter cartridge. The complexity of the operation is simplified by a human–machine interactive interface. A programmable logic controller (PLC) and a LabVIEW human–machine interactive interface are used to dominate the equipment. The Modbus communication protocol is adopted for connecting and communicating between PLC and LabVIEW. The interface can integrate and analyze the process data, including overall equipment effectiveness (OEE), total effective equipment performance (TEEP), loading time, utilization, performance, and yield. The entire production process of the frame-type melt-blown filter cartridge is optimized, and the traditional output of 1000 per day is upgraded to 1300. Overall, the processing speed is increased by up to 30%.

Glufosinate Ammonium-Loaded Halloysite Nanotubes for Slow-Release Weeding Polymer Mulch Films

Improving the performance and giving function to poly(butylene adipate-co-terephthalate) (PBAT)-based biodegradable mulch film have always been research hotspots. However, the problems of a translucent PBAT-based film, which decreases in performance over time and is easily damaged by weeds, need to be solved. In this study, 11.17 wt % of the commercial contact herbicide Glufosinate-ammonium (Glu) was loaded into the lumen of halloysite nanotubes (HNTs). The Glu-loaded HNTs (Glu@HNTs) and other treatment groups were further incorporated into the PBAT/poly(lactic acid) (PLA) composite films by melt blending and blow molding. Results demonstrated that Glu, HNTs, and Glu@HNTs dispersed uniformly in the composite films. Remarkably, while maintaining the original tensile strength of the film, the nominal strain of transverse fracture was increased by 19.6% to 51.2%, and the least water vapor transmission was reduced by 46.7% to 68.5%. Furthermore, the composite films added with Glu@HNTs can successfully kill green bristlegrass and show a good slow-release effect, which can avoid premature release of the herbicide before the weeds grow up. Overall, the combination of inorganic nanofiller-modified PBAT/PLA film and weeding has positive significance for reducing soil pollution and helping the long-term efficient use of biodegradable mulching.

Experimental study on the temperature measurement of melt blowing fibers through use of infrared thermography

ABSTRACT The temperature of melt blowing (MB) and melt spun fibers is frequently measured using infrared thermography (IRT). However, measurements are affected by the size and curvature of the fiber and by reflected radiation from the nozzle. A procedure was developed to obtain accurate measurements of fiber temperature, which corrects fiber size, fiber curvature, and reflected radiation. This procedure is more general than the ones used so far to correct fiber temperature because it corrects the three abovementioned factors using a single correction formula, this being the first time that fiber temperature correction for reflected radiation has been accounted for. It is also more accurate because it uses the local fiber diameter to correct fiber curvature, instead of mean fiber diameter. The procedure was used to measure the temperature of MB adhesive fibers produced by two multi-hole nozzle designs, the results indicating that, in melt blowing applications, the distortion caused by fiber curvature and reflected radiation on the measurement proves to be far more significant than that caused by fiber size, while correction generally leads to an increase in fiber temperature. Considerations as to the effect of different parameters on temperature correction, as well as the quality of thermographic images, are also provided throughout the text. The conclusions emerging from this study allow more accurate temperature measurements of melt blown and melt spun fibers to be obtained.