Oyun Listesi
We usually say that masks are made of non-woven fabrics. Non-woven fabrics are a kind of non-woven fabrics. Textiles are made of oriented fibers or random fibers.
For masks, all raw materials are polypropylene (PP, PP for short). Medical surgical masks usually have a multi-layer structure, which is commonly referred to as an SMS structure.
The national standard GB/T 32610 does not stipulate the several layers of masks that we often talk about. If it is a medical mask, it should have at least three layers, namely SMS (2s and 1m layers). Currently, the top level in China is five floors. Namely SMMMS (2s layer and 3m layer). Making masks is not difficult. The difficulty is to make SMMMS cloth. The price of imported non-woven equipment is hundreds of millions of dollars. One of the most expensive medical non-woven equipment I have encountered is 500 million yuan.
The S in this layer represents spunbond fiber. The fiber diameter is relatively thick, about 20 microns (nm). The two-layer spunbond fiber mainly supports the entire non-woven fabric (mask fabric company) structure, and has no obvious impact on the barrier performance.
The most important thing in the mask is the barrier layer or meltblown layer (M). The fiber diameter of the meltblown layer (sold by mask filters) is relatively thin, about 2 microns (M), so it is only one-tenth of the diameter of the spunbond layer, which is essential to prevent bacteria and blood from entering the spunbond layer .
If the S spunbond layer is too much, the mask is hard, and the sprayed layer M is too much, and breathing is difficult. Therefore, from the ease of use of the breathing mask to the evaluation of the effectiveness of the isolation mask, breathing is more difficult and the barrier effect is better. However, if the M layer is formed into a film, they can hardly breathe, the virus is cut off, and people are dying, so this is a technical problem.
To better illustrate this point, we will compare the shapes of the fibers and hair in the spinning layer M. As shown below, the diameter of the hair is one-third, close to the spunbond layer. The fiber is 1/30 of the diameter of the hair, and the spray coating is close to the diameter of the M fiber. Of course, developers are also developing finer fibers to ensure better antibacterial barrier properties.
As mentioned above, the thinner M layer can prevent small particles such as bacteria from entering. For example, N95 (melt blown factory) means that under normal conditions, it can block 95% of small particles (0.3 microns). According to the national standard GB/T 19083 for medical respirators, when the gas flow rate is 85L/min, the oil-free particle filtration efficiency mask meets the requirements of the following table:
According to the above description, N95 is actually a 5-layer mask made of polypropylene non-woven fabric SMMMS, which can filter 95% of fine particles.
In addition KN95 mask, we also provide FFP2 Mask, please choose us if you need it.