Filters used in surgical masks and respirators are considered “fibrous” in nature – constructed from flat, non-woven mats of fine fibers. Fiber diameter, porosity (the ratio of open space to fibers) and filter thickness all play a role in how well a filter collects particles (ie., type of material, 1 ply vs 3 ply). There are 4 mechanisms by which filters work, 3 mechanical (primarily large particles) and 1 Electrostatic (large and small). N95 respirators are usually manufactured with a melt blown thermoplastic layer sandwiched between multiple fibrous layers
(Source: CDC, others)
Sample specs from a Disposable Face Mask (can vary)
- Inner Layer : Spun-bound polypropylene
- Middle Layer: Melt-blown polypropylene
- Outer Layer : Spun-bound polypropylene
Sample specs from a KN95 mask manufacturer (can vary)
- Non-woven Polypropylene Isolation Layer
- Melt blown Thermoplastic Layer (Electrostatic charged, usually PP)
- Two-ply Heat Sealed Cotton
- Cotton Comfort Layer
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KN95 Masks (100 Masks)$100.00
