A mask as a net for your face.
This net keeps bad things out, like a mosquito net. For the net to be effective, the mesh of the net needs to be small so the bad things can’t leak inside.
So what is the difference between “cloth” and “melt blown fabric”?
They are made differently — woven fabrics and knits are a series of strings tied together in different formations.
Melt Blown Fabric, on the other hand, is a pile of really thin strands of plastic stacked on top of each other.
Why is cloth bad?
Well filtering cloth masks are inherently not breathable.
One way to make a fine mesh is to make really tightly woven or knit material. An example of this is a towel. Yes, towels are great filters, but they are also nearly impossible to breathe through.
You could also stack a bunch of cloth sheets on top of each other, but air gets easily stuck in the strands and between the layers of these masks, which it makes it difficult to breathe through.
How do you make a fine mesh that’s also breathable?
The genius of melt blown fabric is that it’s not a tight weave. Rather, it’s a giant stack of really small twigs that create an obstacle course for the incoming particles.
This allows air to pass through quite easily, but still makes it difficult for particles to pass through.
Also, melt blown fibers are SERIOUSLY small
The finest silk thread is nearly 10X bigger than melt blown fabric threads.This means it can make finer meshes much finer than cloth fabrics.
What about electrostatic charge?
The above are all mechanical reasons why melt blown fabric is more breathable than cloth masks. But another extra cool thing about melt blown fabric is that it holds an electrostatic charge, and this substantially increases its filtration efficiency.
We have some beautiful SEM images that we will upload at a later date to explain this more in depth. Stay tuned!