Broad AirPro Mask HEPA Filter Material PTFE

HEPA” stands for “high-efficiency particulate air” (filter).Filters meeting the HEPA standard must satisfy certain levels of efficiency. Common standards require that a HEPA air filter must remove—from the air that passes through—at least 99.95% (European Standard) or 99.97% (ASME, U.S. DOE) of particles whose diameter is equal to 0.3 μm.; with the filtration efficiency increasing for particle diameters both less than and greater than 0.3 μm. HEPA filters are used in applications that require contamination control, such as the manufacturing of disk drives, medical devices, semiconductors, nuclear, food and pharmaceutical products, as well as in hospitals, homes and vehicles.

It sounds complicated, but HEPA filters are nothing fancy. They were invented back in the 1940s when scientists were developing the atomic bomb, and they’re just a mat of randomly aligned fibers, made from either glass or synthetic materials. Glass fiber, polyester felt or PTFE, all of them can be used for HEPA. The main difference between these materials is the filtration process itself. The filtration with glass fiber or polyester felt media is done within the material. With PTFE filter media, the filtration occurs on the surface and that leads to several advantages; high efficiency with a low-pressure drop and higher energy efficiency and smaller filters.

Broad AirPro Mask HEPA filter use material PTFE.

What is PTFE?
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene. PTFE is hydrophobic which means it is water repellent. On top of that, the material has a very low friction coefficient. Most people know PTFE as the non-stick material used in cookware.

Ultra-thin PTFE film can be made air permeable by controlled stretching. This process creates millions of micropores per sq ft offering a high air permeability.

Normally, high air permeability is considered to be related to lower dust collection efficiency. However, the micropore diameter in PTFE stretched film ranges from 0.1 µm to 10 µm. This is wide enough for air to pass freely but offers excellent dust particle collection.

The filtration process with PTFE stretched film is different to other materials such as glass fiber or polyester felt. Glass fiber and polyester felt need to be of a certain thickness to be efficient as they “trap” the dust particles within a maze of tunnels. The filtration with PTFE stretched film is done at the surface because the micropores act as a gatekeeper.

because of  this behavior, the filter material is almost not contaminated, which offers a considerably lower pressure drop.

PTFE filter materials solved the dilemma between easy-breathing comfort but bigger filters or less comfort but smaller filters. The low-pressure drop of PTFE filter materials have helped the face mask industry like BROAD AirPro Mask to make smaller, yet highly efficient face masks that offer the user the comfort of easy breathing.