Powder size: 8000 mesh, 10000 mesh, nano grade.

Material introduction
Tourmaline powder is the powder obtained by mechanical grinding after removing impurities from the original tourmaline ore. The tourmaline powder has high anion production and far infrared emissivity. Tourmaline is also called Tourmaline. Tourmaline has a general chemical formula of nar3al6si6o18bo33(oh,f)4. The crystal belongs to a group of ring structure silicate minerals of trihedral system. Where R represents metal cation, when R is Fe2 +, it forms black crystal tourmaline. Tourmaline crystals are nearly triangular columns with different crystal shapes at both ends, with longitudinal lines on the surface, often in the shape of columns, needles, radials and massive aggregates. Glass luster, fracture rosin luster, translucent to transparent. No cleavage. Mohs hardness 7-7.5, specific gravity 2.98-3.20. It has piezoelectricity and thermoelectricity.

Tourmaline electret is a kind of material which is made of nano tourmaline powder or particles made of nano tourmaline powder and carrier in the process of melt blown non-woven fabric electret. It is charged under 5-10kv high voltage by electrostatic generator to become electret and improve the efficiency of fiber filtration. Because tourmaline has the function of releasing negative ions, it also has antibacterial property. Electret is a kind of electrolyte material with long-term charge storage function. The electret methods include electrospinning, corona charging, friction electrification, thermal polarization and low energy electron beam bombardment. The tourmaline electret material uses corona charging method to make the fiber carry a certain amount of charge and give the electrostatic filtering function.

The process of melt blown electrostatic electret is to add tourmaline, silica, zirconium phosphate and other inorganic materials into PP polypropylene polymer in advance, then charge the melt blown material by one or more groups of corona discharge with needle electrode voltage of 5-10kv before rolling cloth, and generate air under the needle tip when applying high voltage Corona ionization produces partial breakdown discharge. The carriers are deposited on the surface of the melt blown cloth by the action of electric field. Some of the carriers will go deep into the surface and be trapped by the traps of the electret masterbatch, which makes the melt blown cloth become electret filter material.