N95 or KN95 face mask of less than 95%? Do you feel breathless while wearing a face mask? What kind of masks can you use in a medical setting? The quality of the face mask quality inspection primarily considers performance.
The core material of the mask is Melt blown Nonwoven Fabric. Melt blown Nonwoven Fabric Suppliers determine to a large extent whether the face masks made are eligible. Good melt-blown nonwoven face masks are generally not too bad; test reports usually do breathing resistance tests, filtration efficiency tests, microbial tests, and three other items. If you have to produce a face mask, you must first test the melt-blown nonwoven to see if it is capable. So, that the melt-blown nonwoven fabric does not fail, resulting in the production of the face mask is not eligible, then it is a loss.
Three-Layer Structure Of The Respirators
Most Penetrating Particle Size: In particulate matter purification efficiency testing, matter diameters that face masks easily filter are too large or too small. There is a range of matter diameters that are most difficult to filter, calling the most penetrating unit size. For instance, the 2019-nCoV is around 120nm in size and are the most challenging particle species to filter; bacteria are nearby 3µm in size and are easy to filter. Viral blocking is essentially equivalent to particulate matter purification efficiency.
Principle Of Filtering Matter With A 3-Layer Face Mask
The face masks you use are generally three layers and more. Inner and outer fabrics, mostly polypropylene spunbond nonwoven fabrics, the particle filtration efficiency of which is partial. The middle layer plays a filtering role with the electret polypropylene melt-blown materials; the material can use electrostatic adsorption of units, thus significantly improving the purification efficiency.
The filtration of matter by filtration materials mainly affects gravity settlement, inertial collision, diffusion, interception, electrostatic adsorption, etc. Under the joint action of several filtration mechanisms, there is a most negligible value of filtration efficiency for matter with an aerodynamic particle size around 0.3µm, which is commonly famous as the most easily penetrating particle size.
The fundamental filtration mechanisms of 3-layer face masks are:
Fiber Filtration Mechanism
- Diffuse deposition: The molecular gravity adsorb Brown particle gravity as it moves through the filter fibers. It is easiest to arrest small-scale particles, fine threads, and small particles with low-velocity motion.
- Retained sediment: Larger units moving with the airflow can trap by the mechanical sieving action of the filter material.
- Inertial deposition: the particles pass through the mesh channel of the material; melt blown Nonwoven Fabric Suppliers detach from the airflow due to inertial action hitting the filter fibers, and molecular gravity traps them. High density, large particles, and fast velocity have an excellent interception.
- Electrostatic attraction deposition: The electrostatic action deposits particles of the filter fibers.
Combining the synergy of the above filtration mechanisms, the most easily penetrated particle size is 0.1µm to 0.3µm for standard mechanical media.