Abstract: An improved economically produced clean room ceiling tile formed as a composite comprising a base board and a finish coated paper facer laminated to the base board. The base board is preferably made with excess thickness and is machined to a desired caliper. The machined board is sealed with a clay coating and thereafter coated with a water-based adhesive. The paper facer is laminated to the board with the water-based adhesive and is finish coated with a water-based wet scrubbable coating. The paper facer is easy to laminate, exhibits excellent coverage of surface defects in the base board surface, is fully compatible with the water-based finish coating, and contributes to the sag resistance of the tile.

Abstract: The invention provides an apparatus for forming a panel comprising a mesh support and a transfer plate comprising at least one surface comprising a plurality of pores having an average pore diameter of about 1200 microns or less. The invention further provides a method comprising (i) forming an aqueous composition comprising a fiber material, (ii) depositing the composition onto a movable mesh support to form an entangled fiber material containing water; (iii) removing at least a portion of the water from the entangled fiber material, and (iv) transferring the entangled fiber material from the movable mesh support by passing it over a transfer plate, wherein the transfer plate comprises at least one surface comprising a plurality of pores having an average pore diameter of about 1200 microns or less.