Gypsum based compositions and processes for making and using same
Gypsum based compositions, processes for making same, and articles made therefrom. In one example, the gypsum based composition can include about 1.5 wt % to about 3 wt % of a starch, about 11 wt % to about 14 wt % of a paper, about 0.7 wt % to about 2.3 wt % of vermiculite, about 1.3 wt % to about 3 wt % of a plurality of reinforcing fibers, about 7 wt % to about 10 wt % of a binding agent, about 2 wt % to about 4 wt % of perlite, and about 65 wt % to about 75 wt % of a calcium sulfate, where all weight percent values are based on a combined weight of the starch, paper, vermiculite, plurality of reinforcing fibers, binding agent, perlite, and calcium sulfate.
1. A gypsum based composition, comprising:
about 1.5 wt % to about 3 wt % of a starch;
about 11 wt % to about 14 wt % of a paper;
about 0.7 wt % to about 2.3 wt % of vermiculite;
about 1.3 wt % to about 3 wt % of a plurality of reinforcing fibers;
about 7 wt % to about 10 wt % of a binding agent;
about 2 wt % to about 4 wt % of perlite; and
about 65 wt % to about 75 wt % of a calcium sulfate, wherein all weight percent values are based on a combined weight of the starch, paper, vermiculite, plurality of reinforcing fibers, binding agent, perlite, and calcium sulfate.
2. The gypsum based composition of claim 1 , wherein the gypsum based composition further comprises free water, and wherein the gypsum based composition comprises less than 2 wt % of the free water.
3. The gypsum based composition of claim 1 , wherein the gypsum based composition is in a form of a panel having a thickness of about 3.5 cm to about 4.5 cm, a length of about 2 m to about 3 m, and a width of about 60 cm to about 125 cm.
4. The gypsum based composition of claim 1 , wherein the gypsum based composition has a density of about 0.7 g/cm 3 to about 1 g/cm 3 , as measured according to ASTM D1037-12.
5. The gypsum based composition of claim 1 , wherein the gypsum based composition is in a form of a panel and has at least one property selected from the group consisting of: a minimum face screw holding strength of at least 2,450 N, a minimum hinge-loading of 2,450 N, a minimum vertical door edge screw holding of 2,450 N, and a minimum horizontal door edge screw holding of 1,330 N, wherein all properties are measured according to WDMA T.M. 10-14.
6. The gypsum based composition of claim 1 , wherein the gypsum based composition, without blocking, is rated for use in an extra heavy duty classed fire door, as determined according to WDMA I.S. 1-A-14, and wherein the extra heavy duty classed fire door is rated for at least 90 minutes, as measured according to UL 10C (2009).
7. The gypsum based composition of claim 1 , wherein the plurality of reinforcing fibers comprise glass fibers having an average length of about 0.25 cm to about 2 cm.
8. The gypsum based composition of claim 1 , wherein the binding agent comprises fly ash, sodium silicate, or a cement.
9. The gypsum based composition of claim 1 , wherein the binding agent comprises a cement, and wherein the cement comprises Portland cement Type III.
10. The gypsum based composition of claim 1 , wherein the gypsum based composition comprises:
about 2 wt % to about 2.6 wt % of the starch,
about 12 wt % to about 13 wt % of the paper,
about 1 wt % to about 2 wt % of the vermiculite,
about 1.7 wt % to about 2.5 wt % of the plurality of reinforcing fibers,
about 7 wt % to about 10 wt % of the binding agent,
about 2 wt % to about 4 wt % of the perlite, and
about 67 wt % to about 73 wt % of the calcium sulfate, wherein all weight percent values are based on the combined weight of the starch, paper, vermiculite, plurality of reinforcing fibers, binding agent, perlite, and calcium sulfate.
11. The gypsum based composition of claim 1 , wherein:
the starch comprises corn starch,
the paper comprises post-industrial blank recycled newsprint,
the vermiculite comprises raw vermiculite,
the plurality of reinforcing fibers comprises glass fibers,
the binding agent comprises gypsum,
the perlite comprises expanded perlite, and
the calcium sulfate comprises calcium sulfate dihydrate.
12. A process for making a gypsum based composition, comprising:
mixing a starch, a paper, vermiculite, a plurality of reinforcing fibers, a binding agent, perlite, a calcium sulfate, and water to produce an aqueous mixture comprising about 0.5 wt % to about 1 wt % of the starch, about 2.5 wt % to about 5.5 wt % of the paper, about 0.2 wt % to about 0.8 wt % of the vermiculite, about 0.4 wt % to about 1 wt % of the reinforcing fibers, about 2 wt % to about 3.3 wt % of the binding agent, about 0.5 wt % to about 1.5 wt % of the perlite, about 12 wt % to about 25 wt % of the calcium sulfate, and about 60 wt % to about 80 wt % of the water, wherein all weight percent values are based on a combined weight of the starch, paper, vermiculite, reinforcing fibers, calcium sulfate, perlite, binding agent, and water; and
curing the aqueous mixture to produce the gypsum based composition.
13. The process of claim 12 , wherein the gypsum based composition comprises about 1.5 wt % to about 3 wt % of the starch, about 11 wt % to about 14 wt % of the paper, about 0.7 wt % to about 2.3 wt % of the vermiculite, about 1.3 wt % to about 3 wt % of the plurality of reinforcing fibers, about 7 wt % to about 10 wt % of the binding agent, about 2 wt % to about 4 wt % of the perlite, about 65 wt % to about 75 wt % of the calcium sulfate, and less than 2 wt % of any free water, wherein all weight percent values are based on a combined weight of the starch, paper, vermiculite, plurality of reinforcing fibers, binding agent, perlite, calcium sulfate and any free water.
14. The process of claim 12 , wherein the aqueous mixture is cured by drying the aqueous mixture at a temperature of about 100° C. to about 315° C. for a time period of about 10 minutes to about 24 hours, and wherein the gypsum based composition is in a form of a panel having a thickness of about 3.5 cm to about 4.5 cm, a length of about 2 m to about 3 m, and a width of about 60 cm to about 125 cm.
15. The process of claim 12 , wherein the gypsum based composition has a density of about 0.7 g/cm 3 to about 1 g/cm 3 , as measured according to ASTM D1037-12.
16. The process of claim 12 , wherein the gypsum based composition is in a form of a panel and has at least one property selected from the group consisting of: a minimum face screw holding strength of at least 2,450 N, a minimum hinge-loading of 2,450 N, a minimum vertical door edge screw holding of 2,450 N, and a minimum horizontal door edge screw holding of 1,330 N, wherein all properties are measured according to WDMA T.M. 10-14.
17. The process of claim 12 , wherein the gypsum based composition, without blocking, is rated for use in an extra heavy duty classed fire door, as determined according to WDMA I.S. 1-A-14, and wherein the extra heavy duty classed fire door is rated for at least 90 minutes, as measured according to UL 10C (2009).
18. A laminated structure, comprising:
a first facing layer;
a second facing layer; and
a core disposed between the first facing layer and the second facing layer, wherein the core comprises a gypsum based composition comprising:
about 1.5 wt % to about 3 wt % of a starch,
about 11 wt % to about 14 wt % of a paper,
about 0.7 wt % to about 2.3 wt % of vermiculite,
about 1.3 wt % to about 3 wt % of a plurality of reinforcing fibers,
about 7 wt % to about 10 wt % of a binding agent,
about 2 wt % to about 4 wt % of perlite, and
about 65 wt % to about 75 wt % of a calcium sulfate, based on a combined weight of the starch, paper, vermiculite, plurality of reinforcing fibers, binding agent, perlite, and calcium sulfate.
19. The laminated structure according to claim 18 , wherein the gypsum based building composition has a density of about 0.7 g/cm 3 to about 1 g/cm 3 , as measured according to ASTM D1037-12, and at least one property selected from the group consisting of: a minimum face screw holding strength of at least 2,450 N, a minimum hinge-loading of 2,450 N, a minimum vertical door edge screw holding of 2,450 N, and a minimum horizontal door edge screw holding of 1,330 N, wherein all properties are measured according to WDMA T.M. 10-14.
20. The laminated structure of claim 18 , wherein the laminated structure comprises a fire door without blocking that is rated for at least 90 minutes, as measured according to UL 10C (2009).