How to distinguish melt-blown cloth?How to distinguish melt-blown cloth?
To popularize the identification method of meltblown cloth,
First, look at the eyes. The first one feels like paper. There is a paper feeling. Second, tear it by hand. The tearing feels like tearing the paper, but it is a bit tougher than the paper. Third, test the static electricity by rubbing it on your hair. If it sticks to something, it will be true. Fourth, the lighter will burn and burn. The feeling is the combination of paper and plastic, but it will only melt when it is not exposed to fire. There is also the most important point, whether it is possible to make a virus protection mask is mainly a medical surgical mask and a simple judgment standard of N95 mask material, please read it patiently.
1. It is best to have a test instrument. If not, then use the hair on your arms or legs to get close. If you are attracted, it will carry static electricity. Jingong Fans has equipped Roots blowers for more than 200 meltblown fabric production lines. This is a groping experience. Many meltblown fabric production lines do not have static electrets. The meltblown fabrics produced do not have static electricity. There is no difference, and the naked eye can't tell the difference at all. The filtration efficiency of such melt-blown cloth for tiny particles is not even 50%.
2. In addition to mechanical barriers, mask filtering also has electrostatic adsorption. Fiber filter material is a commonly used material to deal with pollution and purify air and water sources. The dust catching mechanism mainly relies on Brownian diffusion, interception, inertial collision, direct interception and other mechanical blocking effects, but this mechanical blocking effect is very poor in filtering particles with a particle size of less than 1 μm and cannot play a purification role.
In addition to the original mechanical barrier effect, increase electrostatic adsorption during air filtration, rely on Coulomb force to directly attract and capture charged particles in the gas phase, or induce neutral particles to generate polarity and then capture them. Effectively filter the submicron particles in the gas carrier phase, greatly enhancing the filtration efficiency, but the air resistance will not increase. This is the so-called high-efficiency low-resistance filter material. The electret material has exactly this property.
Electret refers to a dielectric material that has the function of storing charge for a long time. The stored charge can be a unipolar real charge (or space charge) injected from the outside, or it can be an ordered orientation of dipoles in a polar dielectric. The resulting dipolar charge, or both types of charge.
After the melt-blown fiber is ejected from the nozzle hole, if it is bombarded by charged protons such as electrons or ions, the melt-blown fiber substrate can become an electret; similarly, when the microfiber substrate is collected, it is made Corona treatment can also make it an electret.
If there is no mask testing instrument, how to know the filtering efficiency of the mask? A simple way is to see if the mask can make the long foot hair stand up when it is close to the thigh! Electret treatment can increase the electrostatic adsorption capacity of the mask, and the electret masterbatch can keep the static electricity for a long time.