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Electrospinning Polymers

Electrospinning Polymers. First, the spun polymer must be converted to a liquid state. A polymeric thermoplastic can then simply be melted, otherwise dissolved or dissolved in a solvent, or chemically treated to form thermoplastic derivatives. The molten polymer is then passed through a mold, then cooled to a rubbery state and then to a solid state.[1] When using a polymer solution, the solvent exits after passing through the nozzle.

Wet spinning is the oldest of the five processes. This method is used for polymers that need to be dissolved in a solvent for spinning. The spray nozzle causes the fiber to be immersed in a chemical bath. fall out and solidify after leaving. This process takes its name from this “wet” bath. Acrylic, viscose, aramid, medacryl and tights are produced with this process.[1] A type of wet spinning: dry jet wet spinning, the solution is extruded and sucked into the air, and then immersed in a liquid bath. In this process, lyocell cellulose is dissolved during spinning.

Electrospinning jets and polymer nanofibers

A solution of a fibrogenic material and a solvent is extruded through a nozzle. A stream of hot air hits the nozzles of the solution emerging from the mold, the solvent evaporates and solid filaments remain. Solution Blowing Spinning is a similar technique where the polymer solution is sprayed directly onto a target. fleece mats. Melt spinning is used for fusible polymers. When the polymer is extruded through a spray nozzle, it solidifies on cooling. Nylon, olefin, polyester, saran and sulfur are produced from this process. Solid polymer pellets or granules, an extruder. Pellets are compressed, heated and melted by an extruder and then fed to a rotating pump and die.

Electrospinning of nanofibers from polymer solutions and melts

Direct spinning avoids the solid polymer pellet stage. Molten polymer is made from raw materials and then pumped from the polymer finisher directly to the spinning mill. Direct spinning is mainly used in the production of polyester fibers and filaments and is intended for high production capacity (> 100 tons per day).

Electrospinning of polymer nanofibers

Gel spinning, also known as wet-dry spinning, is used to achieve high strength or other special properties in fibers. The polymer is in a “gel” state, which somehow holds the polymer chains together, and is only partially liquid. These bonds create strong chain forces that increase the tensile strength of the fibers. Polymer chains in fibers also have a high degree of orientation, which increases strength. The fibers are first air dried and then cooled in a liquid bath. This process produces low tenacity polyethylene and aramid fibers.

Nanometre diameter fibres of polymer produced by electrospinning

Electrospinning uses an electrical charge (usually at the micro or nano scale) to extract very fine fibers from a liquid, polymer solution or molten polymer. Electrospinning has the properties of both electrospray and traditional dry solution spinning[3] of fibers. This process does not require the use of coagulation or high temperature chemistry to produce strong yarns from solution. This makes the process particularly suitable for the production of fibers from large and complex molecules. Electrospinning fusion is also applied. This process ensures that no solvent is transferred to the final product.

Polymer nanofibers assembled by electrospinning

In recent years, various methods for the production and application of nanostructures, especially polymer nanofibers, in the field of bioengineering and tissue regeneration have been developed: nanoscale imaging of nanosystems and polymer nanofibers, polymer phase separation, photolithography and electron beam, chemical. Vapor Deposition, Centrifugal Firing (Spun) is formed by various manufacturing processes such as Electrogravity (E-Spun). The electrospinning process is one of the most important processes among other processes and is used as a simple, inexpensive and efficient technological process in the production of polymer nanofibers. Light weight, nanoscale and diameter of nanoscale fibers are widely preferred in medical applications because of their important features like morphology and surface structure. Composites, filter, protective, electronic and optical materials reinforced with sensors and nanofibers are widely used for biomedical applications of polymer nanofibers obtained by this method.

Electrospinning polymer fibers

Electrospinning polymer fibers. Since the dawn of mankind, the textile industry has undergone greater and more important changes than other industries, changes that have occurred in terms of both raw materials and production methods.

Because despite the rapid increase in world population, the production of fibers, i.e. textile raw materials from natural sources, is not increasing significantly and the production of natural textile raw materials is very limited, especially in Europe. the countries.

assembly of oriented ultrafine polymer fibers by centrifugal electrospinning

In this regard, the production of synthetic fibers has increased significantly compared to fibers derived from natural sources, it is inevitable that this increase is due to the continuous and continuous increase in the world population. When polymers, the main components of fibers, are obtained from natural sources in the form of polymer compounds or through the synthesis of chemical substances, we speak of synthetic fibers. Basically, based on the classification of textile fibers, there are two categories namely natural fiber group and man-made fiber group. In these groups, fibers are divided into 3 groups based on source.

electrospinning of continuous aligned polymer fibers

If the polymers, which make up the main material of fibers, are obtained as polymer compounds from natural sources and converted into fibers by special physical and chemical processes, we speak of regenerated fibers.

If the polymer, which is the starting material for the fibres, is obtained through the synthesis of certain chemicals, we speak of synthetic fibres. There are also fibers whose structure is obtained by human hands from mineral materials called artificial ANORGANIC fibers obtained from glass and metal fibers.

electrospinning of polyurethane fibers polymer

In this process, a polymer solution is prepared in a suitable solvent. این محلول در یک حمام انعقادی تحت فشار ثابت با استفاده از پمپ به سر نازل فرستاده می شود.دلیل اینکه به آن حمام انعقادی با سر نازل می گویند این است که پلیمر در این حمام منعقد می شود.از آنجایی که محلول پلیمری به شکل خارج this works out. The filaments coagulate through the thin holes and thereby collapse. The structure of the coagulation bath is prepared in such a way that the polymer solidifies from the solution state, eg the basic solution of an insoluble polymer. A substance that dissolves in alkaline solutions and does not dissolve in acids is selected as the coagulation bath, and the acidic solution in which the polymer is not dissolved is selected.

Electrospinning polymer fibers

(polymer solution in suitable solvent) This solution is fed to the forming head (nozzle, nozzle) in the coagulation bath with a pump under constant pressure. Spinning heads are those that have one or more holes in the diameter of the thread to be formed, i.e. in the coagulation bath.

polymer fibers by electrospinning

The polymer solution emerging as a thread from the small holes in the forming head coagulates in the bath and coagulates and thus precipitates. The structure of the precipitation bath is prepared in such a way that the polymer solidifies in the solution. The structure of the coagulation bath is made so that it solidifies the polymer from the solution state, for example, a basic solution is made from an insoluble polymer material that is soluble in alkaline solutions and insoluble in acids. The solution in which the polymer is not dissolved is selected as the coagulation bath.

As the polymer solution comes out of the tiny holes in the form of threads, it solidifies and falls out. This is usually a flanged spool around which the threads pass to set the speed and tension in the manufacture of synthetic fibers.

A slight tension is applied to the polymer solution, which is in the form of a string. In order to prepare a polymer solution by this method, the solvent must be a volatile substance with a low boiling point. spinning process) is mostly used for acetate fibers. It is also used to obtain certain polyacrylonitrile fibers.