There are rounded N95 masks, too. The important part is probably the behind-the-head straps.
The greater force means a better seal. But that seal comes from your face deforming to fit a rigid mask, and your face would prefer not to be deformed.
It’s better to use soft polyurethane or foam to seal around the edges, and that’s what some P100 masks do. But because they have higher upfront costs, they have cultural associations with industrial work and gas masks, while people use disposable N95s for things like woodworking. Also, the typical design with 2 flat filters to the sides makes it harder to talk to people while wearing them than disposable N95s do.
Here is a typical disposable P100 mask. It adds a foam seal around the rim, and it’s much more expensive than a N95 mask. I doubt the production cost is that much higher, and in theory, the foam seal could be separate from a replaceable filter.
The important part is probably the behind-the-head straps.
That’s my guess too.
that seal comes from your face deforming to fit a rigid mask
Are you sure? It seems to me that even the most “rigid” masks I’ve tried are still not very hard, and with sufficiently tight straps while my skin deforms slightly the masks deform much more?
Here is a typical disposable P100 mask.
Note that this is a valved mask, so it probably wouldn’t have done well in a source control comparison.
There are rounded N95 masks, too. The important part is probably the behind-the-head straps.
The greater force means a better seal. But that seal comes from your face deforming to fit a rigid mask, and your face would prefer not to be deformed.
It’s better to use soft polyurethane or foam to seal around the edges, and that’s what some P100 masks do. But because they have higher upfront costs, they have cultural associations with industrial work and gas masks, while people use disposable N95s for things like woodworking. Also, the typical design with 2 flat filters to the sides makes it harder to talk to people while wearing them than disposable N95s do.
Here is a typical disposable P100 mask. It adds a foam seal around the rim, and it’s much more expensive than a N95 mask. I doubt the production cost is that much higher, and in theory, the foam seal could be separate from a replaceable filter.
That’s my guess too.
Are you sure? It seems to me that even the most “rigid” masks I’ve tried are still not very hard, and with sufficiently tight straps while my skin deforms slightly the masks deform much more?
Note that this is a valved mask, so it probably wouldn’t have done well in a source control comparison.