The monofilaments are picked up directly underneath the spinneret by a gas stream (normally air), which draws them by applying shear stress to the surface. In contrast to all meltblown processes both the melt and air flows are steadily accelerated. As soon as the internal pressure p_F in the monofilament exceeds the external gas pressure p_G the NANOVAL effect causes the filament to burst open spontaneously. The permanent increase of the internal pressure p_F being due to the presence of hydrodynamic viscous forces, the vapour pressure of lower molecular parts and humidity in the melt. This pressure acts against the tenacity of the monofilament`s skin, which increases with the increase in viscosity caused by its cooling down and the decrease of its diameter. One monofilament can split into a multitude of very fine filaments, it is not unusual to find more than 20 and up to several 100. Nonwovens can be produced either from spliced endless filaments or from monofilaments. With the spinneret nozzles arranged in rows it is possible to deposit the filaments on a conveyor belt running below, at the same time removing the gas/air from underneath the belt by suction fan.

The process is simple, robust in operation and due to the use of cold air, energy saving. Filaments can reach a diameter below 1 µm.

The process is patented.