In structure, the plane mask is generally composed of three layers, namely spunbonded non-woven fabric melt blown non-woven fabric spunbonded non-woven fabric. It is the melt blown non-woven fabric in the middle that can really play a filtering role, so the quality of the melt blown non-woven fabric in the middle will directly lead to the filtering effect of the mask.
A better three-dimensional mask generally consists of five layers, namely, spunbonded non-woven fabric melt blown non-woven fabric filter cotton melt blown non-woven fabric spunbonded non-woven fabric. Two layers of melt blown non-woven fabric in the middle can make the three-dimensional mask have a very strong filtering effect and can prevent PM2.5. However, compared with plane mask, the air permeability of three-dimensional mask is relatively poor. So some high price three-dimensional masks will be equipped with breathing valve to ensure smooth breathing.
In terms of specifications and standards, plane masks are generally divided into three standards: 1. Bfe95 / 99 bacterial filtration efficiency standard; 2. Vfe99 virus filtration efficiency standard; 3. Pfe99 particle filtration efficiency standard.
Three dimensional masks are generally divided into American Standard and European standard, American standard is generally divided into N90, N95 and n99, and European standard is generally divided into ffp1, FFP2 and ffp3
It is worth noting that on the flat mask, the innermost layer of non-woven fabric will be hydrophilic treatment, which is to ensure that the water vapor generated by breathing can be adsorbed on the non-woven fabric.