Air-filtering face masks are very common nowadays because of the coronavirus. Some of the popular masks that are widely-used for coronavirus protection are KN95 masks and N95 masks. These masks have 95% filtering efficiency and can filter particles that are more than 0.3 microns. Both masks are made breathable, comfortable, and lightweight. Most KN95 masks are soft and skin-friendly. The KN95 mask also comes with a nose clip for a nice, closed fit.
KN95 mask vs N95 mask
The N95 mask and KN95 mask are very similar to each other, except for a few minor features. The KN95 mask is regulated under the Chinese accepted standards while the N95 mask is approved and regulated under the United States accepted standard.
Aside from the slight differences in the materials made and overall design, the KN95 mask and N95 mask differ in terms of inhalation and exhalation resistance. The N95 mask has an exhalation and inhalation resistance of 245 Pa and 343 Pa, respectively. While the KN95 mask has 350 Pa inhalation resistance and 250 Pa exhalation resistance.
How is the KN95 mask traps the particles and contaminants?
The KN95 mask protects the wearer by trapping the particles from the air. The KN95 mask is equipped with protective layers that distort the movement of the particles. The KN95 mask has electrostatic energy that pulls the particles towards the mask materials, building up between the protective layers. Because of the particle build-up, the KN95 mask must be discarded after every use.
Five protective layers of the KN95 mask
The KN95 mask is structured differently than the N95 mask. They are made of layers of protective filters but the materials and structure are different. The KN95 mask is made of five protective layers:
- Outer layer - The outer layer has a coating that made the mask durable. It is made from nonwoven material with a water-blocking layer.
- Second layer - This layer is made from PP cotton. It blocks the particles from the immediate environment.
- Melt-blown fabric layer - In this layer, is where the isolation of viruses and bacteria happens.
- PTFE fabric layer - The fabric is heat-resistant. It offers a high level of filtration and it can filter our fine dust. This specific layer is charged electrostatically to trap air particles.
- Inner layer - It is made from nonwoven fabric that absorbs moisture from the nose and mouth, keeping the inner area dry.
Checking the quality of your KN95 mask
Here are different ways on how to check the quality of the KN95 mask:
- Hold the KN95 mask by the ear straps.
- Fill in the KN95 mask with water.
- The KN95 mask is of low quality if there is leakage.
- The KN95 mask should be waterproof to prevent the passage of any bodily fluids and contaminants.
- Get a lighter and wear the KN95 mask.
- Activate the lighter and position it six inches away from your mouth.
- Try to put out the light by blowing it through the KN95 mask.
- The KN95 mask is of low quality if the light blows off.
- The KN95 mask should be firm but breathable.
Other types of mask and their composition
Aside from the KN95 mask, there are other types of disposable face masks that are widely used or in demand because of the coronavirus. These masks include surgical masks and N95 masks.
N95 masks are made of different layers of nonwoven fabric, most often they are made from polypropylene. The outer layers are made from layers of thread with between 20 and 50 g/m2 in density. It has a pre-filtration layer and a filtration layer. The pre-filtration layer is usually made from needled nonwoven material thermally bonded for a thicker and stiffer layer. The filtration layer, the last layer, is made from high efficiency melt-blown electret nonwoven material. It is thermally bonded as well for strength and durability.
Surgical masks are disposable face masks designed to be used in operating rooms. It keeps the room sterile by preventing the germs from the wearer from contaminating a patient during an operation. A surgical mask comes in different filtering levels according to the ASTM classification.
- Minimum - Surgical mask that is recommended for procedures not involving fluid, spray, or aerosol
- Level 1 - Surgical mask that is meant for low-risk situations, procedures not involving fluid, spray, or aerosol
- Level 2 - Surgical mask that delivers protection against moderate aerosol, spray, and fluid
- Level 3 - Surgical mask ideal for heavy exposure to aerosol, fluid, and spray
Surgical masks are generally made from nonwoven fabric because it has better bacteria filtration than a woven cloth. Most surgical masks are made from polypropylene with 20 and 50 g/m2 in density. Others are made from polycarbonate, polystyrene, polyethylene, or polyester.
Cloth masks are made from different types of fabrics. However, according to the CDC, the most effective fabrics for cloth masks are tightly woven fabrics (ex. cotton and cotton blends). The mask also needs to be breathable and comes with at least 2 layers of fabric. A single layer, loose-knit fabrics are not recommended.
Non-medical disposable masks
This type of face mask is very common and widely sold online. Usually, they come in a 3-ply design and have a waterproof coating as well to prevent large droplets of liquid. Non-medical disposable masks have a tight-fitting design and lesser filtering capacity than other masks like KN95, N95, and surgical masks.