Today, the application range of nanofibers are widening day by day because of their excellent properties that are different from conventional materials.
Nowadays, electrospinning is widely used as a versatile and convenient method for the production of nano-sized fibers. However, the difficulty in the production of nanofibers by single-needle electrospinning is that it has low production efficiency. To solve this problem, several types of electrospinning methods have been developed, which can be divided into two broad categories. One is needleless electrospinning and the other is multi-needle electrospinning. Between them, multi-needle electrospinning plays an important role in preparing specific structures because it is able to control the properties of fibers.
So, when the number and density of nozzles are increased in the multi-needle electrospinning, the intended electric field of the nozzles gets more distorted due to electrical interactions between the nozzles, which destabilizes the flow of the polymer solution jet and negatively affects the quality of the obtained fibers. Therefore, the uniformity of the electric field distribution at the spinneret needle tip in the multi-needle electrospinning process is a key factor for producing good quality fibers.
Jang Kum Chol, a researcher at the Institute of Nano Science and Technology, proposed a trapezoidal wave (TW) arranged multi-needle electrospinning spinneret with auxiliary electrodes (AEs), and conducted a study to further enhance the electric field uniformity by optimizing the AE parameters by Taguchi method.
The optimization results showed that the uniformity of electric field was best when the distance between the spinneret and the auxiliary electrode was equal to 21 mm, the arrangement angle of auxiliary electrode 120゜, the spacing between two adjacent needles of auxiliary electrode 18 mm, the needle length of auxiliary electrode 13 mm, the needle diameter of auxiliary electrode 2.5 mm.
For more information, please refer to his paper “Optimization of parameters of auxiliary electrodes for electric field uniformity around spinneret needles in multi-needle electrospinning by using Taguchi method” in “Journal of Electrostatics” (SCI).