Roller electrospinning

Last updated

Roller Electrospinning system a method for producing nanofibres was developed by Jirsak et al.. [1] This method is known under the name Nanospider from Elmarco Company in Liberec. Roller electrospinning is the unique method which has been used in industry to produce nanofibers continuously. Nanospider consists of rotating roller to spin fibers directly from the polymer solution. This roller spinning electrode partially immersed in the tank with the polymer solution. A grounded collector electrode is placed at the top of the spinner . A nonwoven backing material moves along the collector electrode which makes the production of the nanofibre layer a continuous process. Many Taylor cones are simultaneously formed on the surface of the rotating spinning electrode, which makes the technology highly productive. [2] [3]

Contents

Parameters

There are independent and dependent parameters for roller electrospinning.

Independent Parameters

Solution parameters: concentration of polymer solution, molecular weight of polymer, viscosity of polymer solution, surface tension and conductivity of polymer solution.
Process parameters: Applied voltage, velocity of rotating cylinder, collector type, distance from electrodes, velocity of take-up fabric, ambient parameters.

Dependent Parameters

Density of cones,
Life time of jet,
Spinning performance,
Spinning performance per cone,
Non-fibrous area,
Fiber diameter distribution.

Related Research Articles

Spinning is a twisting technique to form yarn from fibers. The fiber intended is drawn out, twisted, and wound onto a bobbin. A few popular fibers that are spun into yarn other than cotton, which is the most popular, are bamboo, and synthetic polyester. Originally done by hand using a spindle whorl, the spinning wheel became across Asia and Europe. The spinning jenny and spinning mule, invented in the late 1700s, made mechanical spinning far more efficient than spinning by hand, and made cotton manufacturing one of the centers of the Industrial Revolution.

Spandex Synthetic fibre known for its elasticity

Spandex, Lycra, or elastane is a synthetic fiber known for its exceptional elasticity. It is a polyether-polyurea copolymer that was invented in 1958 by chemist Joseph Shivers at DuPont's Benger Laboratory in Waynesboro, Virginia, US.

Calender Series of hard pressure rollers that produces a surface effect on fabric, paper, or plastic film

A calender is a series of hard pressure rollers used to finish or smooth a sheet of material such as paper, textiles, or plastics. Calender rolls are also used to form some types of plastic films and to apply coatings. Some calender rolls are heated or cooled as needed. Calenders are sometimes misspelled calendars.

Electrospinning

Electrospinning is a fiber production method that uses electric force to draw charged threads of polymer solutions or polymer melts up to fiber diameters in the order of some hundred nanometers. Electrospinning shares characteristics of both electrospraying and conventional solution dry spinning of fibers. The process does not require the use of coagulation chemistry or high temperatures to produce solid threads from solution. This makes the process particularly suited to the production of fibers using large and complex molecules. Electrospinning from molten precursors is also practiced; this method ensures that no solvent can be carried over into the final product.

The name electrospray is used for an apparatus that employs electricity to disperse a liquid or for the fine aerosol resulting from this process. High voltage is applied to a liquid supplied through an emitter. Ideally the liquid reaching the emitter tip forms a Taylor cone, which emits a liquid jet through its apex. Varicose waves on the surface of the jet lead to the formation of small and highly charged liquid droplets, which are radially dispersed due to Coulomb repulsion.

Rheometer

A rheometer is a laboratory device used to measure the way in which a liquid, suspension or slurry flows in response to applied forces. It is used for those fluids which cannot be defined by a single value of viscosity and therefore require more parameters to be set and measured than is the case for a viscometer. It measures the rheology of the fluid.

Polyester Category of polymers, in which the monomers are joined together by ester links.

Polyester is a category of polymers that contain the ester functional group in every repeat unit of their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include naturally occurring chemicals, such as in plants and insects, as well as synthetics such as polybutyrate. Natural polyesters and a few synthetic ones are biodegradable, but most synthetic polyesters are not. Synthetic polyesters are used extensively in clothing.

Nanofiber

Nanofibers are fibers with diameters in the nanometer range. Nanofibers can be generated from different polymers and hence have different physical properties and application potentials. Examples of natural polymers include collagen, cellulose, silk fibroin, keratin, gelatin and polysaccharides such as chitosan and alginate. Examples of synthetic polymers include poly(lactic acid) (PLA), polycaprolactone (PCL), polyurethane (PU), poly(lactic-co-glycolic acid) (PLGA), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and poly(ethylene-co-vinylacetate) (PEVA). Polymer chains are connected via covalent bonds. The diameters of nanofibers depend on the type of polymer used and the method of production. All polymer nanofibers are unique for their large surface area-to-volume ratio, high porosity, appreciable mechanical strength, and flexibility in functionalization compared to their microfiber counterparts.

Nanofabrics Textiles engineered with small particles that give ordinary materials advantageous properties

Nanofabrics are textiles engineered with small particles that give ordinary materials advantageous properties such as superhydrophobicity, odor and moisture elimination, increased elasticity and strength, and bacterial resistance. Depending on the desired property, a nanofabric is either constructed from nanoscopic fibers called nanofibers, or is formed by applying a solution containing nanoparticles to a regular fabric. Nanofabrics research is an interdisciplinary effort involving bioengineering, molecular chemistry, physics, electrical engineering, computer science, and systems engineering. Applications of nanofabrics have the potential to revolutionize textile manufacturing and areas of medicine such as drug delivery and tissue engineering.

Polymer nanocomposites (PNC) consist of a polymer or copolymer having nanoparticles or nanofillers dispersed in the polymer matrix. These may be of different shape, but at least one dimension must be in the range of 1–50 nm. These PNC's belong to the category of multi-phase systems that consume nearly 95% of plastics production. These systems require controlled mixing/compounding, stabilization of the achieved dispersion, orientation of the dispersed phase, and the compounding strategies for all MPS, including PNC, are similar. Alternatively, polymer can be infiltrated into 1D, 2D, 3D preform creating high content polymer nanocomposites.

Spinneret (polymers) Any structure natural or artificial used to extrude polymers into fibers

A spinneret is a device used to extrude a polymer solution or polymer melt to form fibers. Streams of viscous polymer exit via the spinneret into air or liquid leading to a phase inversion which allows the polymer to solidify. The individual polymer chains tend to align in the fiber because of viscous flow. This airstream liquid-to-fiber formation process is similar to the production process for cotton candy. The fiber production process is generally referred to as "spinning". Depending on the type of spinneret used, either solid or hollow fibers can be formed. Spinnerets are also used for electrospinning and electrospraying applications. They are sometimes called coaxial needles, or coaxial emitters.

Spinning is a manufacturing process for creating polymer fibers. It is a specialized form of extrusion that uses a spinneret to form multiple continuous filaments.

Polyaniline nanofibers

Polyaniline nanofibers are a high aspect form of polyaniline, a polymer consisting of aniline monomers, which appears as discrete long threads with an average diameter between 30 nm and 100 nm. Polyaniline is one of the oldest known conducting polymers, being known for over 150 years. Polyaniline nanofibers are often studied for their potential to enhance the properties of polyaniline or have additional beneficial properties due to the addition of a nanostructure to the polymer. Properties that make polyaniline useful can be seen in the nanofiber form as well, such as facile synthesis, environmental stability, and simple acid/base doping/dedoping chemistry. These and other properties have led to the formation of various applications for polyaniline nanofibers as actuators, memory devices, and sensors.

Metal spinning

Metal spinning, also known as spin forming or spinning or metal turning most commonly, is a metalworking process by which a disc or tube of metal is rotated at high speed and formed into an axially symmetric part. Spinning can be performed by hand or by a CNC lathe.

Melt electrospinning

Melt electrospinning is a processing technique to produce fibrous structures from polymer melts for applications that include tissue engineering, textiles and filtration. In general, electrospinning can be performed using either polymer melts or polymer solutions. However, melt electrospinning is distinct in that the collection of the fiber can very focused; combined with moving collectors, melt electrospinning writing is a way to perform 3D printing. Since volatile solvents are not used, there are benefits for some applications where solvent toxicity and accumulation during manufacturing are a concern.

Wet process engineering is one of the major streams in textile engineering which refers to the engineering of textile chemical processes and associated applied science. The other three streams in textile engineering are yarn engineering, fabric engineering, and apparel engineering. The processes of this stream are involved or carried out in an aqueous stage. Hence, it is called a wet process which usually covers pre-treatment, dyeing, printing, and finishing.

A die in polymer processing is a metal restrictor or channel capable of providing a constant cross sectional profile to a stream of liquid polymer. This allows for continuous processing of shapes such as sheets, films, pipes, rods, and other more complex profiles. This is a continuous process, allowing for constant production, as opposed to a sequential (non-constant) process such as injection molding.

Melt blowing Micro- and nanofiber fabrication method

Melt blowing is a conventional fabrication method of micro- and nanofibers where a polymer melt is extruded through small nozzles surrounded by high speed blowing gas. The randomly deposited fibers form a nonwoven sheet product applicable for filtration, sorbents, apparels and drug delivery systems. The substantial benefits of melt blowing are simplicity, high specific productivity and solvent-free operation. Choosing an appropriate combination of polymers with optimized rheological and surface properties, scientists have been able to produce melt-blown fibers with an average diameter as small as 36 nm.

Advanced thermoplastic composites (ACM) have a high strength fibres held together by a thermoplastic matrix. Advanced thermoplastic composites are becoming more widely used in the aerospace, marine, automotive and energy industry. This is due to the decreasing cost and superior strength to weight ratios, over metallic parts. Advance thermoplastic composite have excellent damage tolerance, corrosion resistant, high fracture toughness, high impact resistance, good fatigue resistance, low storage cost, and infinite shelf life. Thermoplastic composites also have the ability to be formed and reformed, repaired and fusion welded.

Hydrogel fiber

Hydrogel fiber is a hydrogel made into a fibrous state, where its width is significantly smaller than its length. The hydrogel's specific surface area at fibrous form is larger than that of the bulk hydrogel, and its mechanical properties also changed accordingly. As a result of these changes, hydrogel fiber has a faster matter exchange rate and can be woven into different structures.

References

  1. Jirsak O.; Sanetrnik F.; Lukas D.; Kotek V.; Martinova L.; Chaloupek J. (2004). "A Method of Nanofibres Production from a Polymer Solution Using Electrostatic Spinning and a Device for Carrying Out the Method". European Patent. EP 1 (673 493).
  2. Yener F.; Jirsak O. (2012). "Comparison Between the Needle- and Roller Electrospinning of Polyvinylbutyral". Journal of Nanomaterials. 2012: 1–6. doi: 10.1155/2012/839317 .
  3. Yener F.; Jirsak O. (2011). Improving Performance of Polyvinyl Butyral Electrospinning. Nanocon. Brno, Czech Republic.