| abstract |
A process and apparatus for creating an acoustically absorbent porous panelncomprises the steps of dispensing cement and fibers with a dry mixer to create a drynmix and aqueous mixing water, surfactant and air with an aqueous mixer to create anfoam. The process and apparatus provides for combining and mixing the foam andndry mix in a combining mixer to form a foamed cementitious material comprising onna wet basis about 53% to about 68% by weight cement, about 17% to about 48% bynweight water, about 0.05% to about 5% by weight fibers, and about 0.01% to aboutn10% by weight surfactant. The foamed cementitious material is then dried or curednin a drying chamber. The dried foamed cementitious material may then texturednwith an embossing roller. The cementitious material provides good acousticalnperformance with enhanced durability and moisture resistance. |