Meltblown Webs Research Articles

Microstructure and physical properties of composite nonwovens produced by incorporating cotton fibers in elastic spunbond and meltblown webs for medical textiles

The objective of this research was to produce elastomeric nonwovens containing cotton by the combination of appropriate process. Such nonwovens are in demand for use in several healthcare, baby care, and adult care products that require stretchability, comfort, and barrier properties. Meltblown fabrics have very high surface area due to microfibers and have good absorbency, permeability, and barrier properties. Spunbonding is the most economical process to produce nonwovens with good strength and physical properties with relatively larger diameter fibers. Incorporating cotton fibers into elastomeric nonwovens can enhance the performance of products, such as absorbency and comfort. There has not been any study yet to use such novel approaches to produce elastomeric cotton fiber nonwovens. A hydroentangling process was used to integrate cotton fibers into produced elastomeric spunbond and meltblown nonwovens. The laminated web structures produced by various combinations were evaluated for their physical properties such as weight, thickness, air permeability, pore size, tensile strength, and especially the stretch recovery. Incorporating cotton into elastic webs resulted in composite structures with improved moisture absorbency (250%-800%) as well as good breathability and elastic properties. The results also show that incorporating cotton can significantly increase tensile strength with improved spontaneous recovery from stretch even after the 5th cycle. Results from the experiments demonstrate that such composite webs with improved performance properties can be produced by commercially used processes.

Effect of Process Parameters on Fiber Diameter and Fiber Distribution of Melt-Blown Polypropylene Microfibers Produced by Biax Line

Meltblown nonwovens market has been continuing to grow because of the unique characteristics of allowing the production of microfiber webs directly from a thermoplastic polymer in a single step. Whereas a vast majority of meltblown processes have utilized the traditional Exxon die, the Biax-die has also been used in some processes. The aim of this study was to understand the effect of critical process conditions of the Biax process, which has the advantage of lower high pressure hot air consumption compared to the traditional process, on the structure of meltblown webs. As the performance properties of meltblown nonwovens are mainly determined by the fiber diameter and diameter distribution, this study focused on these two characteristics considering various process conditions such as melt temperature, melt throughput, air temperature and air pressure. In conclusion, it was observed that there were three distribution types, the normal distribution, log-normal distribution, and skewed log-normal distribution, for meltblown webs produced by the Biax process. Air pressure and melt throughput were the most effective process conditions on the fiber diameter of meltblown polypropylene webs. It was also observed that fine fiber webs close to one-micron average fiber diameter and relatively narrower fiber diameter distribution can be produced under appropriate processing conditions using the Biax process.

Numerical Study of Melt-Blown Fibrous Web Uniformity Based on the Fiber Dynamics on a Collector

Fabricating a uniform melt-blown web was a complicated engineering problem. A complementary study to our previous model was conducted to aid in the optimization of the prediction of fibrous web for...

Association study between basis weight distribution of melt-blown web and air velocity distribution on the collector

Basis weight distribution of melt-blown fibrous web is attracting considerable interest because it directly affects the application performance of nonwovens. Basis weight distribution is strongly determined by the air velocity distribution on the top surface of the collector. However, how the mentioned air velocity distribution affects basis weight distribution is still unknown. Measurement of the mentioned two distributions is the first step to investigate the influence mechanism. Thus, this work measures air velocity distribution on the collector under different processing conditions. Then the fibrous web is fabricated under same conditions. After fabrication, the basis weight distribution of fibrous web is analyzed by using image analysis method. The effects of processing conditions, including velocity of air jet and suction, die-to-collector distance, and pore size of the collector, on the air velocity distribution and basis weight distribution are quantitatively analyzed. The results demonstrate that higher suction speed and air jet velocity, smaller die-to-collector distance, and larger pores of the collector result in higher air velocity on the top surface of the collector. On the other hand, higher suction speed and air jet velocity, larger die-to-collector distance, and smaller pores of the collector create evenly distributed basis weight. In addition, the correlation between basis weight distribution and air velocity distribution is discussed based on the Spearman correlation analysis method. High correlation demonstrates that air velocity and basis weight display similar distribution on the collector. Namely, both of air velocity and basis weight in the central zone are larger than those in the fringe zone on the collector.

RAPID VISUALIZATION OF THE MASS DISTRIBUTION PROFILE OF ELECTROSPUN LAYERS

Nanofibrous materials are currently widely used in many different areas. One of the technologies commonly used for their production is electrospinning. The mass distribution in a produced nanofibrous layer is a crucial factor especially for filtration applications and active ingredients or drug release applications. Image analysis is an efficient non-destructive method of a mass distribution determination, which has already been used in the evaluation of textiles and melt-blown webs, but so far only a few publications have dealt with its use in the field of electrospun materials. To facilitate the process of image analysis of deposited nanofibers, we developed a new collector electrode, which makes it possible to determine the optical mass distribution profile of the produced layer. A series of experiments proved that the developed collector allows an easy evaluation of the appearance of nanofibrous layers as well as the effects of many associated factors such as emitter configuration on the resulting sample. The results showed how the properties of nanofibrous layers (such as deposition zone dimensions, location of these zones, mass distribution profiles produced by different spinning nozzles) can change during the electrospinning process. The advantages of the method described in the present article are that it allows a contactless and non-destructive determination of mass distribution, detection of macroscopic defects, and investigation of causes behind layer thickness inhomogeneities. All in all, the presented method is a useful research and development tool for the field of electrospinning.

Porosity and barrier properties of polyethylene meltblown nonwovens

There are several areas in which textiles have been highly desirable due to their specific and high performance for many industries and sectors including in civil engineering, automobile, medicine, filtration, and electronics. Polymer used has a significant effect on the properties of meltblown nonwovens. Polypropylene being the most commonly used polymer, very limited data have been reported on the polyethylene meltblown nonwovens which are desired due to their unique processing and performance advantages. In this study, we have investigated the effects of process variables, die temperature, air pressure, and die-to-collector distance on some characteristics of polyethylene meltblown nonwovens such as pore size, air permeability, hydrostatic head, and SEM analysis. It was observed that the variables have significant effects on the produced nonwovens, and many of the properties are comparable to those obtained with that of polypropylene meltblown webs.

Study on uniformity of a melt-blown fibrous web based on an image analysis technique

Abstract Melt blowing is a one-step process to manufacture products with superfine fibers with diameter <5 μm (and even below 1 μm). As an intermediate product, a melt-blown (MB) web provides a strong influence on the functional properties of the final MB products. In this paper, the influence of processing conditions on the uniformity of a MB web is studied using an image analysis technique, including nominal air jet pressure, polymer volume flow rate, air suction velocity, and the moving speed of the collection belt. This study enables us to quantify the influence of the processing conditions on the uniformity of MB fibrous web.

Computational Fluid Dynamics Simulations and Experiments of Meltblown Fibrous Media: New Die Designs to Enhance Fiber Attenuation and Filtration Quality

The meltblowing process employs high-speed hot air jets to attenuate polymer streams injected from a die head. In this study, we examine design strategies to control the air flow field below the polymer injection point to achieve higher fiber attenuation and meltblown webs with smaller fiber diameters. Computational fluid dynamics (CFD) simulations for new die configurations show that vertical or inclined air constrictors around the primary air jets keep the centerline air velocity and temperature at their maximum values for 10–15 mm longer below the die face than the reference die. Polymer streams are kept near their melting temperatures at higher air velocities for a longer period, resulting in higher fiber attenuation. The underlying mechanisms leading to such behavior are discussed. Experimental results show reduction in fiber diameter and pore size, validating the simulation. Improved filtration properties are also obtained from the nonwovens webs.

IR Spectroscopy of Polypropylene Fibrous Carrier before and after its Surface Modification with Metal Nanoparticles

In this paper, we present an IR spectroscopy study of the molecular and supramolecular structure of the polypropylene fibre, used as a metal nanoparticle carrier, by the example of nanoparticles of tin dioxide. The aim of this work is to investigate the changes in the chemical structure of the polypropylene melt-blown web when modified with the tin dioxide nanoparticles. The paper shows that the metal-oxygen valence vibration bands appear in the IR spectra of modified polypropylene fibrous carriers. At the same time, the carrier material remains stereoregular and possess a helical structure.

Effects of Poly(ϵ-caprolactone) on Structure and Properties of Poly(lactic acid)/Poly(ϵ-caprolactone) Meltblown Nonwoven

To obtain flexile poly(lactic acid)-based melt-blown nonwoven filtration material, poly(lactic acid)/poly(ϵ-caprolactone) melt-blown nonwoven with various components were melt-spun by melt-blown processing in the Melt-blown Experiment Line. The 3 wt.% tributyl citrate to poly(ϵ-caprolactone) was added in the composites as compatibilizer. The effect of poly(ϵ-caprolactone) on the structure, morphology, mechanical and filtration properties of poly(lactic acid)/poly(ϵ-caprolactone) melt-blown nonwoven was reported. Scanning electron microscopy micrographs revealed good dispersion of the additive in the fiber webs. The crystallinity of melt-blown webs with poly(ϵ-caprolactone) was more than that of poly(lactic acid) alone. The tensile strength, ductility and air permeability of poly(lactic acid) melt-blown nonwovens were enhanced significantly. The input of poly(ϵ-caprolactone) increased the diameter of fibers and decreased the filtration efficiency of poly(lactic acid)/poly(ϵ-caprolactone) melt-blown nonwoven.

The Preparation and property of poly(lactic acid)/tourmaline blends and melt‐blown nonwoven

Poly(lactic acid) melt‐blown (MB) webs were melt‐spun by MB processing of poly(lactic acid) and poly(lactic acid)/filler blends. The effect of tourmaline particles on the structure, morphology, mechanical and filtration properties of poly(lactic acid) blends, and MB webs were reported. The blends and MB webs were characterized using differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WXRD), scanning electron microscopy (SEM), and pore size meter (PSM). The degree of crystallinity of blends with tourmaline particles was more than that of poly(lactic acid) alone. SEM micrographs revealed a good dispersion of the additive in the blends and fiber webs. The tourmaline particles offered some benefits to the mechanical properties of the MB web. MB web samples with tourmaline had larger pore size, high surface charge density, and higher filtration efficiency. POLYM. COMPOS., 36:264–271, 2015. © 2014 Society of Plastics Engineers

Filtration Efficiency of Submicrometer Filters

Meltblown technology has recently gained a lot of attention in the production of submicrometer fiber webs with a fiber size less than 1 μm. Single layer polypropylene meltblown webs with fiber diameters ranging from 520 to 2100 nm were produced using nano and micro dies. To our best knowledge, there are no substantial data in the public domain on the filtration characteristics of single layer stand alone submicrometer meltblown webs and their comparison with micrometer sized webs. This paper focuses on the influence of fiber diameter on the filtration characteristics of standalone single layer submicrometer and micrometer sized meltblown webs. Submicrometer single layer webs showed higher filtration efficiency and a higher quality factor, whereas webs with fiber diameters more than a micrometer showed lower filtration efficiency and a lower quality factor.

Aerosol filtration properties of nucleating agent containing electret filters

This study reports on the effects of nucleating agents on morphology, charging, and electrostatic filtration performance of polypropylene meltblown webs. Two commercial nucleating agents, DMDBS (3:2, 4‐bis(3,4‐dimethyldibenzylidene) sorbitol) and NA11 (sodium 2,2′‐methylene‐bis(4,6‐di‐tertbutylphenyl)‐phosphate) were compared. It is hypothesized that faster solidification brought about by the addition of the nucleating agents may be responsible for the slight increase in fiber diameter and concomitant reduction in web solidity. Samples were charged at room temperature as well as at elevated temperatures. Upon thermal charging, significant enhancement in the electrostatic potential and filtration performance of the webs was observed. Particularly, the stability of electrostatic filtration performance was found to be promising with the addition of these polarizable additives. Dielectric spectroscopy tests confirmed an increase in capacitance for samples containing nucleating agents. POLYM. ENG. SCI., 54:1533–1539, 2014. © 2013 Society of Plastics Engineers

Numerical simulation and analysis of fluid flow in double melt-blown die

Melt-blown die usually consists of two components: the coat-hanger feed distributor and the spinneret plate with a series of orifices. In this paper, fluid flow in double melt-blown die was simulated using the three-dimensional finite element method. The fluid flow inside the melt-blown die was analyzed, particularly the flow near the joint point of the double melt-blown die and the entrance of the orifice. Velocity distribution at the outlet of the die was also analyzed through a comparison with the fluid flow in the double melt-blown coat-hanger feed distributor. The results show that the convergence flow around the entrance of the orifice can improve the velocity distribution at the die’s outlet to a certain extent. The improved uniformity of the velocity distribution at the outlet of the double melt-blown die proves the feasibility of using side-by-side melt-blown die to fabricate wider uniform melt-blown webs.

Fabrication of nanofiber meltblown membranes and their filtration properties

Meltblowing is a unique one-step process for producing self-bonded fibrous nonwoven membranes directly from polymer resins, with average fiber diameter ranging between 1 and 2μm. Determining routes for making nano- or submicron-fibers using this process are desirable since there are many manufacturing assets that are already in place. It is envisaged that these nonwoven membranes will find applications in critical areas such as medical, hygiene, filtration, bioseparation, and others. In this study, we investigate the influence of different die configurations and operating conditions on fiber and web characteristics. We also report on strategies for reducing the fiber size below one micron to achieve higher filtration quality at lower basis weight relative to the conventional meltblown webs. Their performance is compared to a control meltblown sample produced by using a typical die design. We find that production of nano-meltblown membranes with an average fiber size in the range of 300–500nm using this new die design is possible and report on process operating conditions that result in such structures. These samples achieve equal filtration efficiencies to that of our control sample at 88% reduced basis weight but at a lower polymer throughput. The lower basis weight also resulted in a lower pressure drop and overall, the new samples exhibited a higher quality factor, twice that of the control. These results show significant promise for the use of nano-meltblown fibers in filtration applications.

Effects of Tourmaline Particles on Structure and Properties of Polypropylene Filtration Melt-Blown Nonwoven Electrets

Polypropylene (PP) melt-blown electret webs were melt-spun by melt-blown processing of PP and PP/filler composites. The effect of tourmaline particles on the structure, morphology, and mechanical properties of PP melt-blown webs is reported. The melt-blown webs were characterized by differential scanning calorimetry, wide-angle x-ray diffraction, scanning electron microscopy (SEM), and pore size meter. The crystallinity of melt-blown webs with tourmaline particles was more than that of PP alone. SEM micrographs revealed good dispersion of the additive in the fiber webs. The tourmaline particles offered some benefits to the mechanical properties of the melt-blown web. Melt-blown web samples with tourmaline had larger pore size, high surface charge density, higher filtration efficiency and stability of filtration efficiency.

Penetration Performance of Melt-Blown Polypropylene Electret Nonwoven Web against DEHS Aerosols

High filtration efficiency of melt-blown polypropylene nonwoven web used as air filter extremely depends on its elelctret characteristics. In this paper, penetration performance of DEHS(diethyl hexyl sebacate) aerosol while flowing through melt-blown polypropylene electret nonwoven web is studied by the method of aerosol penetration measurement as a function of particle size, and the contribution of mechanical and electrostatic mechanism to its capture ability is proposed. The stability of filtration performance after exposure to DEHS for a period of time is measured and the impact of DEHS and other challenge aerosols with different chemical properties on filtration performance is compared. The results show that the higher filtration efficiency of melt-blown polypropylene electret nonwoven web mainly depends on its high electret charge. Aerosol penetration drops off with the increase of aerosol particle size and decreases in the order of basic weight sequence of 20, 40 and 60 g/m2. The most penetration particle size (MPPS) appears at 0.08 m in diameter. The electret charge of the web was cleared away during the course of exposure to challenge aerosol after 5 minutes. The electriferous property of aerosol particle also influences the filtration performance of polypropylene electret nonwoven web. The electret web displays the best filtration performance for ionized aerosol.

Research Progress of Elastic Nonwovens with Meltblown Technology

Meltblown elastic nonwovens are produced with thermoplastic elastomers by meltblown process. The elastic meltblown web is composed of microfibers, so it has big specific surface-area, good insulator and filtration. And it has improved the elasticity of traditional meltblowm web as well. In addition with nonwoven composite technology, meltblown elastic nonwovens combining with other material’s characteristics are applied widely in medical treatment, costumes, electronic industry, dug industry and other fields. The principle of elastic nonwovens with meltblown tehcnology and recent research progress are briefly overviewed. The aim of this paper is providing a reference for further study on this technology in china. Meanwhile put forward the direction of recent study on elastic meltblown webs and forecast the bright future of elastic nonwoven with meltblown technology.

The Method of Producing Nanomaterials and Melt Blown Nonwovens Composites

The paper expounds the special properties of the nanomaterials, introduces the properties of the melt blown nonwovens and the advantages of nanomaterials and melt blown nonwovens composites, summarizes the methods of incorporating the nanoparticles into the melt blown webs at home and aboard and the advantages, disadvantages of different methods, finally, introduces the new method we taking in the study and the result of our study. The results show that activated carbon is good distributed on the meltblown nonwoven and activated carbon particles embedded within the fiber.

Nanoparticle effects on structure and properties of polypropylene meltblown webs

AbstractThe effect of nanoclay additive on the structure, morphology, and mechanical properties of polypropylene meltblown webs is reported here for the first time. Effect of nanoclay on the meltblown processing, resultant fiber web structure, and properties are discussed. Combination of wide‐angle x‐ray diffraction, differential scanning calorimetry, and transmission electron microscopy were used to determine the nature of clay dispersion in the polypropylene fiber matrix and resultant morphology. Transmission electron microscopy micrographs revealed nanolevel dispersion of the additive in the fiber web. Clay additive did not offer any benefit as far as the mechanical properties of the meltblown web are concerned. Meltblown web samples with nanoclay had higher variability in web structure, high air permeability, high stiffness, and lower mechanical properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010