We usually say that masks are non-woven materials. Non-woven fabrics(SS Non Woven Fabric Factory) are non-woven fabrics, which are made of oriented or random fibers.

Specific to the mask, all its raw materials are polypropylene (Polypropylene, PP for short), and medical masks generally have a multilayer structure, generally referred to as an SMS structure.

The several layers of masks we often say are not specified in the national standard GB/T 32610 of masks. If it is a medical mask, it should be at least 3 layers, that is, SMS (2 layers S layer and 1 layer M layer) ), currently the highest number of layers in China is 5 layers, namely SMMMS (2 layer S layer and 3 layer M layer), it is not difficult to make a mask, the more difficult is to make SMMMS cloth, the price of an imported non-woven equipment is all It is billions of dollars.

The S in this represents a spunbond layer (Spunbond), the fiber diameter is relatively thick, about 20 microns (μm), the two layers of S spunbond layer is mainly used to support the entire non-woven fabric structure, does not have much effect on the barrier .

The most important thing in the mask is the barrier layer or the melt-blown layer M (Meltblown). The fiber diameter of the melt-blown layer is relatively thin, about 2 microns (μm), so it is only one tenth of the diameter of the spunbond layer. This prevents Bacteria and blood penetrate its vital role.

If the S spunbond layer(White PP Nonwovens Manufacturer) is too much, the mask is harder, and if the meltblown layer M is too much, it is more difficult to breathe, so the isolation effect of the mask can be judged from the difficulty of breathing the mask. The more difficult the breathing, the better the blocking effect However, if the M layer becomes a thin film, it will basically be unable to breathe, the virus is blocked, and people will soon be unable to do it, so this is also a technical problem.

In order to explain the problem better, we compare the S fiber of the spunbond layer, the M fiber of the meltblown layer and the hair as follows, 1/3 of the hair diameter is close to the fiber of the spunbond layer, and 1/30 of the hair diameter, and melt The diameter of the M fiber of the sprayed layer is close. Of course, the R&D personnel are still developing finer fibers to ensure better antibacterial barrier.

As mentioned earlier, the finer the M layer, the more able to block the entry of microscopic particles such as bacteria, such as N95, which means that under normal circumstances, it can block 95% of microscopic particles (0.3 microns), according to the national standard for medical protective masks GB/ T 19083 requires that when the gas flow rate is 85 L/min, the filtering efficiency of the mask for non-oily particles.

From the above explanation, N95 is actually a 5-layer mask made of polypropylene non-woven SMMMS(China SS Nonwovens On Sales) that can filter 95% of fine particles.