Posted on 01/14/2022 7:01:38 PM PST by E. Pluribus Unum
N95 mask construction
https://pubs.acs.org/doi/10.1021/acsapm.0c01294
EXCERPT
Filtration occurs by the following four major mechanisms:
inertial impaction,
interception,
diffusion, and
electrostatic interaction. (14−16)
The formation of smaller fibers as well as thicker and denser matts will improve all filtration characteristics, except electrostatic interaction, and generally increase the pressure drop. (10,17,18)
An electret is an electric analog of a magnet and creates a permanent electric field.
The formation of electrets in fibrous filter media creates the ability to significantly enhance filtration efficiency without increasing the pressure drop.
The application of charge via corona treatment creates electrets within the fabric that greatly enhance the filtration efficiency.
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That said, I have read elsewhere, that some masks also use some chemical mixtures that make some of the fibres “tacky.”
And, to clarify “inertial impaction” - this refers to an object that fails to complete a turn, along with the air that does complete a turn, while passing thru the mask fibre complex.
H/T jonrick46
Bongino Bookmark
Why require "masks" in the first place? You seem to have accepted the narrative that masks should be required.
Masks don't make a darn bit of difference and the only people (outside of maybe dentists and surgeons) who willingly wear them are allowing themselves to become tools, compliant and submissive slaves of the nanny government.
I guess I wasn’t clear enough; I was talking about those blue paper ones they give out for free in stores, the same kind that doctors and dentists wear back when.
I guess I wasn’t clear enough; I was talking about those blue paper ones they give out for free in stores, the same kind that doctors and dentists wear back when.
You are OK. I was merely adding N95 info to the page. BTW, some droplets do get thru N95 masks.
In general regarding mask types available to the [general] public, almost all of the masks function as defusers that reduce load concentrations.
I read where you can get that COVID through your eyes. I only use that N-95 mask. Question: how long is it good for? Can you spray denatured alcohol on it to sanitize it?
There are challenges in maintaining the physical and electrostatic properties of N95 masks after certain decontamination methods. The multilayer sandwich structure of N95 masks, like the 3M model 8210 (Fig. 1), consists of an outer layer (coverweb) that faces the environment, middle layers (filters 1 and 2), and an inner layer (shell) that faces the user (10).Based upon info I found at Battelle Labs research combined with Duke Univ. Medical Ctr., I use what you might call a Hydrogen Peroxide vapor “bath.”
The 3M 8210 mask materials are polyester for the coverweb and shell, polypropylene for filters 1 and 2, thermoplastic elastomer for the straps, aluminum for the nose clip, and polyurethane for the nose foam.
Filters 1 and 2 are the internal filtering medium, the key material of the N95 mask. The internal filtering medium is a proprietary Brownian filtration media that traps particles that collide with a specially treated surface, which is made of electrostatically charged meltblown polypropylene microfibers. These microfibers have cross-sectional diameters in the range of 2–10 mm and cross each other to form a three-dimensional porous structure with up to 90% porosity (3).
The microfibers are electrostatically charged to attract and trap particles and increase filtration efficiency without impeding air flow (11). Decontamination methods with 75% alcohol or a chlorine-based solution dramatically reduce the filtration performance of N95 masks, likely because of breakdown of the electrostatic charge on the filter material, and are not recommended (3).
On the other hand, ultraviolet germicidal irradiation (UVGI) has been shown to efficiently inactivate pandemic influenza virus applied as aerosols or droplets on several different N95 masks (12–14).
My point isn’t about the rightness or wrongness of masks. The fact is that workplaces ARE requiring them.
I”m just concerned as to why we don’t have our own supply.
And that goes for a lot of other things.
Do you know how many of our pharmaceuticals are reliant on foreign supply?
Steel?
Petroleum?
I could go on...But if you’re so concerned about mere masks, I guess the conversation is over.
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