Light weight gypsum fiber panel suitable for use as roof cover board
AssigneeUnited States Gypsum Company
InventorsYufeng Xu, Eugene S. Stivender
Life of this patent
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Abstract
A roof cover board made from a mixture of 30-60% stucco; 20-50% perlite; 10-30% cellulose fiber; 3-20% starch; and siloxane. Also disclosed is a stucco-free roof cover board made from a mixture of 30-60% perlite, 30-60% cellulose fiber, 5-25% starch; and siloxane. Also disclosed are methods for making same.
Claims20
A roof cover board made from a mixture of, on a water free basis, in wt. %:
- 30-45% stucco (calcium sulfate hemihydrate);
- 20-50% perlite;
- 15-30% cellulose fiber;
- 8-20% starch;
- and
- 0.2 to 2% siloxane.
A roof cover board made from a mixture of, on a water free basis, in wt. %:
- 30-60% perlite,
- 30-60% recycled cellulose fiber,
- 5-25% starch, and
- 0.2 to 2% siloxane;
- having an absence of stucco,
- having an absence of bituminous material,
- having an absence of newsprint, and
- containing less than 5% polymer;
- and
- the board having a weight between 450 and 600 lbs/MSF and a density of between 11 and 14 lbs/ft3.
A method of manufacturing the roof cover board, using a wet forming process comprising:
- mixing a composition containing:
- perlite,
- recycled cellulose fiber,
- starch,
- siloxane, and
- water
- to form a furnish with a consistency of 3-10%;
- the composition in wt. % on a water free basis being a mixture of:
- 30-60% perlite,
- 30-60% recycled cellulose fiber,
- 5-25% starch, and
- 0.2 to 2% siloxane,
- having an absence of stucco,
- having an absence of bituminous material,
- having an absence of newsprint, and
- containing less than 5% polymer;
- dewatering the furnish on a moving wire to form a pad;
- optionally, pressing the pad to further remove water and achieve desired thickness and surface smoothness,
- cutting the pad to form green board;
- and
- drying the green board in a kiln, the dried board having a weight between 400 and 685 lbs/MSF, and a density of between 10 and 17 lbs/ft3.
A roof cover board made from a mixture of, on a water free basis, in wt. %:
- 45-55% perlite,
- 35-45% recycled cellulose fiber,
- 8-12% starch, and
- 0.2 to 2% siloxane;
- having an absence of stucco,
- having an absence of bituminous material,
- having an absence of newsprint, and
- containing less than 5% polymer;
- and
- the board having a weight between 400 and 685 lbs/MSF and a density of between 10 and 17 lbs/ft3.
Dependencies are inferred from the claim text.