Free surface electrospinning

Basics


Electrospinning (ES) is the basic technology of EFTEK LLC.  ES leads to the formation of fibers via electrostatic forces effect on a charged jet of polymer solution or melt. High voltage (10-100 kV) is applied to the polymer solution or melt, which induces the like electric charges in it. These charges, as a result of the Coulomb electrostatic interactions, lead to the stretching of the polymer solution into a thin jet, and its further splitting to the finer ones. The resulting fibers are cured by evaporation of the solvent and drift to the oppositively-charged substrate under the influence of electrostatic forces. Thus-deposited fibers form a nonwoven fibrous material.
ES method is characterized by high energy efficiency of production of micron, submicron and nanofibers, wide variety of materials to be spinned, and flexibility in managing the process parameters. This makes ES attractive for industrial nonwoven nano-, submicro-and microfibrous materials.

Traditional ES equipment includes the capillary system. The polymer solution is extruded through them. Despite the widespread use of capillary technology, including the manufacture of Petryanov materials and based on it products, the method has some drawbacks:
  • minimum diameter of the fibers - 250 nm.
  • clogging of the capillaries that leads to the inhomogeneity of fibrous layer.

Free surface ES does not have these deficiencies.

 

Advantages and peculiarities of the technology


High-quality new materials to meet the needs of various industries are created by free-surface  electrospinning.
Today this method is the only that allows to produce nanofibrous materials on an industrial scale.

The technology provides a fundamentally high level of the properties of nonwovens:
  • reduce the fiber diameter to 50 nm, and get the fiber in a narrow range of diameters - the confidence interval does not exceed 15%
  • widely vary surface density nanolayer - from 0.05 to 20 g/m2
  • obtain a uniform layer of nanofibers even with the minimum density
  • control the porosity and specific surface nanolayer
  • incorporate the catalytic and other functional additives
  • improve the performance of the ES due to the absence of clogging