To talk about the production process of masks, we must first talk about the core raw material of masks: non-woven fabrics. Non-woven fabrics are non-woven fabrics. Although they are called non-woven fabrics, the formation of non-woven fabrics still requires fibers? Some friends may wonder, isn’t cotton a fiber, can’t you use cotton? The answer is no, you don’t need cotton and fiber, of course, choose artificial synthetic fiber!
The non-woven fabric is made of pp polypropylene. Through high-speed hot air, the melted pp polypropylene is blown into extremely fine fibers. Flying onto a drum, the fibers are randomly bonded to each other under high temperature, rolling continuously, and superimposed into a cloth. Here is a key quality indicator of non-woven fabrics, that is, gram weight, the weight per unit area of non-woven fabrics. The grammage represents the density and thickness of the non-woven fabric structure.
This kind of fiber can be as thin as 0.25 microns, and there must be gaps between the fibers, but the layers are squeezed and bonded together to form a labyrinth-like channel, so that the non-woven fabric has its own natural filtering properties. , For example: the diameter of droplets produced by our sneeze is 0.5 microns to 12 microns, so it is very good to prevent dust and droplets. But this does not reach the medical grade level, at most it is a dust mask. To reach the medical grade, the next important process is to make the fibers electrostatically charged, and increasing the electrostatic absorption effect can further improve the filtration efficiency. This is the electret charging process of the filter material.
In this way, does the 95% filtration efficiency achieve anti-virus and anti-bacteria? Still can not! Because medical masks need ethylene oxide sterilization and disinfection before leaving the factory, and they must be left for a period of time to reach the residual standard before leaving the factory.
The above is the analysis of the standard medical mask production process.
Post time: Aug-24-2022