For many of us, the assumption might be that all P2 masks are created equal, designed to offer a uniform level of protection against airborne particles. What you might not realise is that not all P2 masks are built the same. While shopping for face masks, particularly P2 or even N95 masks, you might have come across terms like "meltblown" or "nano-fibre" filters. It's easy to overlook these terms, assuming all masks are fundamentally the same and simply make a purchase.

These aren't just fancy marketing terms – they actually refer to two distinct types of filtration technology that can significantly impact a mask's performance.

Functions of filters in masks

Various types of masks, ranging from everyday surgical masks to more robust respirators like P2 or N95 masks, are equipped with specific types of filters built into them. These filters are engineered to trap tiny particulate matter, which can originate from multiple sources such as pollution like smog, industrial processes, viruses, dust, and smoke from bushfires.

Here's an overview of the key functions of filters in masks:

1. Particle filtration

The primary function of any mask filter is to capture airborne particles that could contain viruses, bacteria, dust, pollen, and pollution. Different filters are designed to target particles of varying sizes, but typically, N95 masks are tested to block at least 95% of particles that are 0.3 microns in diameter—the size considered most difficult to capture. Similarly, particulate P2 masks are designed to filter out particles as small as 0.3 microns but with at least 94% efficiency. This includes a wide range of pollutants, pathogens, and particulates. But AMD P2 masks take things a step further because of their innovative nanofilter technology. These filters are made with ultra-fine fibers that form a dense web, trapping 99.66% of airborne particles – that's significantly higher than the standard P2 minimum and puts them on par with many N95 masks!

2. Breathability

While high filtration efficiency is important, the filter must also allow enough air through to ensure that the wearer can breathe comfortably. This balance is essential, as a filter that is too restrictive can make the mask uncomfortable and impractical for long-term wear.

3. Moisture resistance

Effective filters also need to resist moisture from the wearer's breath and external humidity. Moisture can compromise the structural integrity of the filter, reducing its effectiveness by causing the fibres to stick together and allowing particles to pass through more easily.

4. Reusability and longevity

Filters vary in their reusability. Some are designed for single use, while others can withstand multiple cleanings or sanitisations without a significant reduction in their ability to filter particles. This not only makes them more cost-effective over time but also helps in reducing environmental waste.

Filtration efficiencies of mask standards equivalent to P2 and N95

Various countries have their own standards for respiratory protective equipment, each with its own equivalent to the P2 and N95 masks. While the standards may vary slightly in terms of testing methods and requirements, the overall filtration efficiencies of masks meeting these standards are comparable.

Filtration efficiency comparison:

Country	Type	Filtration Efficiency
Australia/NZ	P2	≥ 94%
United States	N95	≥ 95%
China	KN95	≥ 95%
Europe	FFP2	≥ 94%
South Korea	KF94	≥ 94%

 

Meltblown vs. nano-fibre filter

Now that we've covered the basics of what you can expect from standard P2 or N95 masks, let's delve into the details about the differences between meltblown and nano-fibre filters. These two types of filters represent distinct technologies that play a crucial role in the performance and effectiveness of respiratory protective equipment.

Meltblown filters

Meltblown filters are made by extruding melted polymer resin through tiny nozzles under high pressure, creating a web of fine fibres. In the meltblown process, hot, high-velocity air is applied, which draws the polymer filaments into very fine filaments, typically around 1 micron in diameter. This results in the creation of ultrafine fibres that possess both excellent filtration properties and good insulating properties. The fine diameter of these fibres contributes to the formation of a dense web-like structure, maximising the surface area available for particle capture.

Filtration mechanism:

The filtration efficiency of meltblown filters is primarily based on mechanical capture. As particles pass through the filter, they collide with the fibres, causing them to be trapped within the matrix. The fine fibre diameter and high surface area enhance the chances of particle capture, even for smaller particles.

Characteristics:

• Meltblown filters are effective in capturing a wide range of particle sizes, including both large and small particles.
• They are commonly used in various types of masks, including surgical masks and respirators like P2 and N95 masks.
• Meltblown filters provide a balance between filtration efficiency and breathability, making them suitable for extended wear.

Nano-fibre filters

Nano-fibre filters are composed of ultra-fine fibres with diameters in the nanometer range, typically less than 100 nanometers. These fibres are often electrospun, a process in which a high voltage is applied to a polymer solution to draw out extremely thin fibers.

Filtration mechanism:

The filtration mechanism of nano-fibre filters involves both mechanical capture and electrostatic attraction. The small size of the fibres creates a dense network with a high surface area, facilitating mechanical filtration. Additionally, the electrostatic charge on the fibres enhances the capture of charged particles through electrostatic attraction.

Characteristics:

• Nano-fibre filters are highly efficient in capturing even smaller particles, including viruses and ultrafine dust particles.
• They offer superior filtration performance compared to meltblown filters, especially for ultrafine particles.
• Nano-fibre filters are often used in advanced respirators and masks designed for high-risk environments where maximum protection is required.

Source: Polymers

So, which one should you wear for better protection?

When it comes to respiratory protection, both standard and nano-fibre P2 or N95 masks offer superior filtration efficiency compared to other types of masks, such as surgical masks, however, when deciding between wearing a standard P2 mask or a nano-fibre P2 mask, it's crucial to assess the environment and the nature of the activities involved.

Nano-fibre filters:

Nano-fibre filters excel in capturing ultrafine particles, including viruses and fine particulate matter. As such, they are particularly well-suited for use in high-risk environments where maximum protection is essential, such as healthcare settings, industrial workplaces with high levels of airborne contaminants, or during activities like sanding, painting, or handling hazardous materials. So you might want to consider opting for the AMD P2 masks as they provide 99.66% Particle Filtration Efficiency (PFE) compared to standard P2 masks. 

Meltblown filters:

Meltblown filters, on the other hand, are highly versatile and suitable for a wide range of applications. They provide effective filtration of both large and small particles, making them suitable for everyday use in various settings. Standard P2 masks equipped with meltblown filters are ideal for routine activities such as commuting, running errands, or engaging in light outdoor activities like walking or gardening. These masks offer reliable protection against common airborne pollutants, dust, and allergens encountered in everyday environments.

The choice between the two ultimately depends on the specific requirements of the task or environment in which the mask will be used, with considerations for filtration efficiency, comfort, and breathability.

• Share on:
• WhatsApp
• Deel
• Tweet
• Pin it
• Messenger
• Email

---

Tags

P2 /N95 Face Masks PPE Safety & Protection