The production of smallest structures from micro- to nanofibers enables a highly efficient application in areas such as acoustics and filtration. Special emphasis is increasingly placed on promoting the development of environmentally friendly, solvent-free and ultimately cost-efficient manufacturing processes. The aim is to produce modern processes for nanofibers from polypropylene and other thermoplastics.
Harry Albus of JX Nippon, respectively of the JXTG Nippon Group, presents some current examples in his report in the trade journal “Technische Textilien” (3/18): Cross Laminated Airy Fabric (CLAF), Milife and nanofibers from multifilaments.
CLAF is used to reinforce nonwovens, foils, paper, etc. High tensile and tear strength, breathability, water and chemical resistance and dimensional stability in further processing are the “core competencies” of reinforcing fabrics. The aim is to increase the performance of the textile and reduce production costs. Bonding with other materials can be carried out thermally or by ultrasound, as well as by all other common laminating processes and by needle or water steel bonding.
High tensile and tear strength, good breathability, dyeability, printability and dimensional stability in further processing characterize the polyester nonwoven fabric “Milife”. The molecular orientation of polyester melt-blown continuous filaments gives this melt-blown nonwoven high tensile strength combined with low basis weights and material thicknesses. During the process, a silk-like surface is created using a special process.
In addition to reinforcing other textiles, the aim of this development is particularly to optically and haptically refine the resulting final textile. Applications include interior design (e.g. pleats and wall coverings), packaging, medicine, adhesive tapes and other materials.
Nanofibers, Fanned Out By Vacuum And Melted By Laser
Solvent-free production of nanofibers from polypropylene is another focus of development at JXTG. The development of the laser-supersonic-stretching method makes it possible to produce nanofibers solvent-free, more homogeneous, more productive and, in addition to many other thermoplastics, also from polypropylene. The starting products from which the nanofibers are made are multifilaments that are drawn into a production chamber by means of a vacuum.
The vacuum causes the multifilaments to vibrate and they fan out. The individual filaments now released are melted – hit by a CO2 laser. The permanent vacuum draws the nanofibers from each individual filament, which are then homogeneously deposited on a freely selectable nonwoven carrier.