| 摘要 |
A method for making acoustical tile having a pattern of raised portions and portions in relief on the tile surface is provided by contacting deformable, acoustical tile fiber composition pulp with a hollow embossing roll containing the pattern in reverse and interstices communicating from the surface of the roll into the hollow interior of the roll; pressing the roll against the deformable pulp with sufficient force as to dispel the pulp; vent air, between the roll and the pulp surface, through the roll and produce the reversed pattern of the roll upon the pulp surface; and releasing the pulp from the surface of the roll by rotation of the roll. |
