Abstract: A process for using shredded scrap or virgin fiber glass in combination with starch, water and other components to make ceiling tiles. The tiles are made by initially preparing a mixture of water, starch, boric acid and fire clay. That initial mixture is then heated to form a gel. Fiber glass is then added to the gel to form a pulp. The pulp is fed into trays to form slabs. The slabs are dried and finished into tiles.

Abstract: A process for consistently making ceiling tiles having uniform density and surface texture includes using a conveyor along which trays are moved in a generally horizontal direction. A feeder box is used to deposit pulp in the trays, the pulp being comprised of a mixture of water, starch, fibrous material, and other ingredients. The feeder box through which pulp is deposited in the trays is of a special design, and includes a sloping front edge which creates a negative rake angle with respect to layers produced by the system. The lower front edge of the feeder box includes a surface having a compound curvature. Ceiling tiles are produced by the process having improved uniformity of density and surface texture.