Linear fibrous formation with a coating of polymeric nanofibers enveloping a supporting linear formation constituting a core, a method and a device for producing it

A system for production of a linear fibrous formation, the system comprising:

• a spinning chamber;
• a feeding device disposed so as to feed a supporting linear formation to the spinning chamber;
• a spinning electrode arranged in the spinning chamber and connected to a source of AC electric voltage,
• wherein a hollow electrically neutral plume of polymeric nanofibers is formed in a spinning space above the spinning electrode in the spinning chamber such that in the spinning space in a vicinity of a front face of the spinning electrode and above it the plume is changed into a flat stripe having an organized structure of nanofibers, which is guided to the circumference of the supporting linear formation;
• a draw-off device disposed to withdraw the linear fibrous formation from the spinning chamber;
• a twisting device disposed in a path of the supporting linear formation, the twisting device configured to create a false twist in, or a rotating balloon from, the supporting linear formation in the spinning chamber;
• and
• wherein as a result of the false twist or ballooning of the supporting linear formation moving through the spinning chamber, the plume of polymeric nanofibers is wound around the supporting linear formation in a form of the flat stripe having the organized structure with the nanofibers forming a helix.