Non-woven fabric according to the netting process

Non-woven fabrics are divided into:


①, spinning into a net


Spinning process principle: The polymer chips are fed into the screw extruder, after melting, squeezing, filtering, and metering, they are ejected from the spinneret hole, and the filament tow is cooled and drawn evenly after the airflow. Lay on the condensation net curtain, the formed filament web is thermally bonded, chemically bonded or needle-punched to become a spun-laid non-woven material.


②, air-laid


After the fiber is opened, impurity-removed and mixed, it is fed to the main carding mechanism. After further carding, it is in a single fiber state. Under the combined action of the centrifugal force and airflow generated by the high-speed rotation of the cylinder, the fiber is removed from the tooth It falls off and gathers on the netting curtain by the air transport disease, forming a three-dimensional fiber network with random arrangement of fibers.


③, comb into a net


The raw materials are still in the form of fiber blocks or fiber bundles after being opened by the opener, and the arrangement of the fibers is also disordered. The task of the carding machine is to further loosen the fiber assembly after opening, increase the degree of fiber separation under the premise of reducing fiber damage as much as possible, so that the fiber bundle can be divided into a single fiber state, and the fiber can be further compared. Mix carefully and evenly.


④, Electrospinning


Electrospinning is a special form of electrostatic atomization of polymer fluids. At this time, the atomized substance is not tiny droplets, but polymer tiny jets, which can run for a long distance and finally solidify into fibers. Electrospinning is a special fiber manufacturing process in which polymer solutions or melts are jet-spinned in a strong electric field. Under the action of the electric field, the droplet at the needle will change from a spherical shape to a conical shape (that is, a 'Taylor cone'), and extend from the tip of the cone to obtain fibrous filaments. In this way, polymer filaments with nanometer diameter can be produced.


⑤, flash evaporation method


Flash evaporation method, also known as instantaneous solvent volatilization method, uses dry spinning technology instead of melt spinning. That is to say, the high polymer is dissolved in a certain solvent to make a spinning solution, which is then sprayed from the spinneret, and the high polymer is re-solidified into fibers due to the rapid volatilization of the solvent. At the same time, the dry spinning technology used by the flash method is different from the ordinary dry spinning, which is mainly reflected in the fact that the flash method uses a lower spinning solution viscosity, while at a very high pressure and speed from the spinneret hole Squirting out. Due to the viscosity and fluidity of the solution, the liquid filaments solidify in high-speed motion to form extremely thin fiber filaments, and finally are absorbed on the web to form a web directly.