The N95 mask is a type of disposable personal protective equipment. The N95 mask is widely used in both medical and industrial fields. It comes in different styles, designs, and models. The N95 mask is regulated and approved by the United States National Institute for Occupational Safety and Health.
The N95 mask is very similar to the KN95 mask. The KN95 mask is also an air-filtering device that follows the Chinese standards. It is also widely used in both medical and industrial fields. The KN95 mask also has the capacity to filter small airborne particles and bodily fluids.
Both the KN95 mask and the N95 mask have 95% filtering efficiency. These two face masks have become very useful nowadays because of the coronavirus pandemic. Before the pandemic, the United States only allowed N95 masks to be used by the medical and healthcare workers. But because of the shortage of supply, the CDC and the FDA approved several types of KN95 masks to be used for emergencies in the healthcare and medical institutions.
How N95 masks and KN95 masks are made
Both the N95 mask and the KN95 mask offer a high level of protection. They are similar in so many ways but there are also a few things that set them apart from each other. These masks have the same purpose to provide protection but they differ in their overall structure and how they are manufactured.
Basically, there are two types of respirators - the air-supplying and the air-filtering types. The N95 mask is an air-filtering respirator and this mask is the most in-demand air-filtering mask across the United States because healthcare workers need the N95 masks in treating patients infected with the coronavirus.
The N95 mask is made of several layers of nonwoven fabric. Usually, it is made from polypropylene. The outward protective layers of the N95 are created using spun bonding, creating layer threads between 15-35 micrometers on a conveyor belt. The fibers are then bonded using thermal techniques. The outer layers of the N95 mask have between 20 to 50 grams per square meter in density.
In between the outer layers are the pre-filtration layer and the filtration layer. The pre-filtration layer can be as dense as 250 grams per square meter. The pre-filtration layer is run through a hot calendaring process, thermally bonding the materials and running them through high-pressure heated rolls.
The filtration layer is run through the melt-blown process that is similar to spun bonding. The fibers for this layer are much smaller (less than a micron).
The KN95 mask consists of five protective layers and they are structured differently from the N95 masks. Here's how the KN95 mask made:
- Outer layer - The outer layer of the KN95 mask has a coating that made the mask durable. The material is made from nonwoven material with a water-blocking layer.
- Second layer - This layer of the KN95 mask is made from PP cotton. The layer blocks the particles from the immediate environment.
- Melt-blown fabric layer - In this layer of the KN95 mask, it is where the isolation of viruses and bacteria happens.
- PTFE fabric layer - The fabric used in this layer is heat-resistant. It offers a high level of filtration and it can filter our fine dust. This layer of the KN95 mask is charged electrostatically to trap air particles.
- Inner layer - The inner layer of the KN95 mask is made from nonwoven fabric that absorbs moisture from the nose and mouth, keeping the inner area dry.
Both the N95 masks and KN95 masks are sterilized before shipping out from the manufacturer.
Testing the N95 masks and KN95 masks
The N95 masks and the KN95 masks are tested to ensure that it delivers the protection they intend to deliver. Here are several ways to test the masks:
- Test for particle penetration - This test is done using charge neutralized sodium chloride aerosol spray that has a median of 0.3 microns.
- Test for a moderately high-work rate - This is done by having an airflow rate of 85L per minute.
- Breathability test - Test for breathing resistance at 35mm and exhalation resistance at 25mm.
- Test for the level of exposure This test is done by loading 200mg of aerosol, clogging the mask up for high-level exposure.
KN95 mask Water test
- Hold the KN95 respirator by the ear straps.
- Fill in the KN95 respirator with water.
- The KN95 respirator is of low quality if there is leakage.
- The KN95 respirator should be waterproof to prevent the passage of any bodily fluids and contaminants.
KN95 mask Flame test
- Get a lighter and wear the KN95 respirator.
- Activate the lighter and position it six inches away from your mouth.
- Try to put out the light by blowing it through the KN95 respirator.
- The KN95 respirator is of low quality if the light blows off.
- The KN95 respirator should be firm but breathable.
Other types of face masks
Other types of face masks that are widely used in recent times because of the coronavirus are the following:
- Surgical mask - Intended for the healthcare workers, especially those who are caring for COVID-19 patients
- Cloth mask - Recommended being used by the general public. Because it is highly breathable, it is also recommended for older people.
- Disposable non-medical mask - These are widely used and sold online. This mask has a loose-fitting design but effective enough to filter large fluid droplets.