First of all, both liquid silicone rubber and solid silicone rubber masks are medical silicone products. Their differences are:

Silicone rubber can be divided into liquid silicone rubber and solid silicone rubber according to its existing form. Due to their different forms, their physical properties are also different, which also leads to significant differences in applications. This paper will mainly discuss the difference between liquid silicone rubber and solid silicone rubber.

Distinguish from die steel:

Generally, S136 heat treatment and imported NAK80 are used for molding solid silicone mold.
The liquid injection mold is NAK80, etc
PVC injection molds generally use 718H, S136, NAK80, etc

Material of mask:

Solid silica gel generally uses rubber mixture materials, etc
Liquid silica gel uses medical grade lsr, etc
PVC: PVC resin

Disposable or reusable:

Disposable mask: PVC
Reusable mask: solid silicone/liquid silicone.

Operating temperature:

Liquid silicone mask: - 20 ℃ - 450 ℃
Silicone mask: - 40 ℃ - 230 ℃
PVC mask: - 10 ℃ - 85 ℃

For Silicone rubber, please check the details:
https://www.htvsilicone.com/product-methyl-vinyl-silicone-rubber-iota3110.html