Method of and apparatus for producing gypsum fiber boards (plasterboard)
AssigneeBabcock-BSH GmbH
InventorsKurt Eberhardt, Heinrich Blackert, Gerald Forbert, Josef Steinkuhl, Horst Hose, Friedrich Bahner
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Abstract
A method of and apparatus for producing gypsum fiber boards includes introducing shaped boards provided of a mash of calcium sulphate dihydrate and fibrous material and possibly additives after dewatering and shaping the mash into at least one pressure vessel and to heat the boards at saturated steam atmosphere to 120.degree.-160.degree. C. over a predetermined period. Thereafter, the boards are allowed to cool down within the pressure vessel to a temperature of about 100.degree. or less before being discharged therefrom.
Claims9
A method of producing gypsum fiber boards, comprising the steps of:
- (a) combining water, calcium sulfate dihydrate and fiber material to form a mash and adjusting the pH of said mash to a value of at most 7;
- (b) forming the mash into shaped boards with a moisture content of less than 40 weight-percent;
- (c) heating the shaped boards in a pressure vessel in a saturated steam atmosphere to a temperature between 120.degree. and 160.degree. for a period between 3 and 50 minutes;
- and
- (d) releasing steam from said pressure vessel at a rate such that the pressure therein is reduced by at most 1 bar per minute and cooling the shaped boards within the pressure vessel to a temperature of at most 100.degree. C., said shaped boards being clamped between formed elements during said steam release step.
Dependencies are inferred from the claim text.