Fabrication and characterisation of polypropylene nanofibres by meltblowing process using different fluids

In nonwoven industry, meltblowing has been widely used as an important technique for the production of nonwoven webs consisting of microfibres, suitable for various applications. Recently, great attention is being paid to fabricate nonwoven webs consisting of nanofibres, commonly known as nanowebs. In this paper, polypropylene has been successfully used for the fabrication of nanowebs by meltblowing process with the injection of different fluids (such as air and water) at the vent port of commercial meltblowing equipment. The lowest average fibre diameters achieved were 755 and 438 nm by the use of air and water, respectively. Differential scanning calorimetry results showed the presence of single melting peaks in the first heating cycle and double melting peaks in the second, due to the re-crystallisation and re-organisation by heating during the experiments. The results obtained from thermo gravimetric analysis and intrinsic viscosity studies showed thermal degradation of the nanofibres during meltblowing. X-ray diffraction studies showed that all the meltblown polypropylene fibres produced with the injection of the fluids contained low degrees of crystallinity and monoclinic α-form crystals. The crystallinity was increased with annealing. Similar Fourier transform infrared spectra of the polymer and the fibres indicated no change to the chemical functionality of the nanofibres by the application of the fluids and high temperature during meltblowing.