National Gypsum Company

John L Phillips

Herman C Fraley

Apparatus and method for producing gypsum board, comprising apparatus for coating a cover sheet with a relatively high density gypsum slurry, apparatus for forming edge borders on the sheet with relatively high density gypsum slurry, and apparatus for forming a core on the coating and between the edge borders, the core comprising a relatively low density gypsum. The apparatus for coating the sheet comprises a relatively soft pressure roll and a relatively hard coating roll, the two rolls being normally pressed together to form a nip between them and a sheet to be coated passing through the nip. The pressure roll is below the sheet and the coating roll, and the axis of the pressure roll is offset from the axis of the coating roll in upstream direction of the movement of the sheet. The pressure roll has a surface area which contacts and moves in the same direction as the sheet, and the coating roll has a surface area which contacts and moves in the opposite direction of the sheet. A trough is formed between the upper side of the sheet and the coating roll, and a relatively high density gypsum is poured into the trough. The rotating coating roll picks up a quantity of the slurry from the trough and wipes it onto the sheet to form a high density gypsum coating.

Growing community of inventors

Vacaville, CA, United States of America

John L Phillips