Experimental Study Of Producing Micro-Nano Fibers By Melt Electrospinning

At present,the vast majority of research activity has been focused on solution electrospinning with far fewer studies of melt electrospinning because of the more complicated apparatus and thicker fibers in the case of melt electrospinning.Fibers having a diameter smaller than 1O0 nm,can be produced through electrospinning,however,there are a number of disadvantages of solution electrospinning associated with the use of volatile solvents.Melt electrospinning,studied in this paper,is a cheaper,more environmentally friendly,and safer alternative to solution electrospinning in producing ultra-thin fibers,hence it is more hopeful to make the industrialization of electrospinning come true.The key problems of melt electrospinning now are how to diminish the fiber diameter from micrometer to nanometer,and how to increase its efficiency in order to lay the foundation for its industrialization.In this paper,the author did a lot experimental studies,which are big contribution to solve the two key problems of melt electrospinning and greatly facilitated the pace of industrialization of electrospinning technology.Various factors of the melt electrospinning process were studied in a melt electrospinning device made by the author.Good quality fibers with smooth and even surfaces,most of which had diameters smaller than 15 microns,were electrospun successfully by improve the spinning temperature of LDPE,whose melt flow index is very low(2g/10min),in a higher level(315～355℃,little lower than its decomposition temperature). Fibers with smooth and even surfaces,most of which had diameters of several nanometers,were electrospun successfully by choosing the melt blow nonwoven PP polymer(RPP1400) which has a ultra-high melt flow index.The smallest diameter of the PP fibers is 190nm.An orthogonal test was done to study the impact of weight on fiber diameter and standard deviation among four factors(spinning temperature,voltage,spinning distance and melt flow index).Melt flow index was found to have the biggest impact of weight on fiber diameter and standard deviation.High efficiency melt electrospinning apparatus and high efficiency continuous production melt electrospinning apparatus were developed successfully, which can greatly increase the efficiency of melt electrospinning.Each high efficiency nozzle has a high efficiency of 4g/h.Carried out experiments on several classic polymers(PP,PA,PET, PLA and PCL) which used in fibers usually.Ultra-thin fiber of PP,PA,PET, PLA and PCL were electrospun successfully,all of which can be compared with the fibers produced by melt spinning in industry except of the PCL fibers.