Low Density Gypsum Panel

1 - 30 . (canceled)

31 . A gypsum panel comprising a gypsum core and a facing material,

the gypsum core comprising gypsum, a foaming agent, and optionally starch in an amount of less than 4 wt. % based on the weight of gypsum,

wherein the gypsum core includes air voids having an average void size of microns or more,

wherein the gypsum panel has a density of 33 pcf or less, a weight of 1,800 lbs/MSF or less, and an NRC value of 0.2 or more.

32 . The gypsum panel of claim 31 , wherein the foaming agent includes an alkyl sulfate foaming agent.

33 . The gypsum panel of claim 31 , wherein the gypsum panel has a density of 25 pcf or less.

34 . The gypsum panel of claim 31 , wherein the gypsum panel has a density of 16.5 pcf or less.

35 . The gypsum panel of claim 31 , wherein the gypsum panel has a weight of 1,500 lbs/MSF or less.

36 . The gypsum panel of claim 31 , wherein the gypsum panel has a weight of 1,000 lbs/MSF or less.

37 . The gypsum panel of claim 31 , wherein the gypsum panel has a thickness of about ⅝″.

38 . The gypsum panel of claim 31 , wherein the gypsum panel has an interconnected core structure.

39 . The gypsum panel of claim 31 , wherein the facing material comprises a paper facing material.

40 . The gypsum panel of claim 31 , wherein the facing material comprises a glass mat facing material.

41 . The gypsum panel of claim 40 , wherein the glass mat facing material comprises glass fibers having an average diameter of from 3 microns to 23 microns.

42 . The gypsum panel of claim 31 , wherein the facing material has an air porosity of from 50 l/m 2 /s to 2,000 l/m 2 /s.

43 . The gypsum panel of claim 31 , wherein the gypsum panel has a flexural strength of from 10 lb f to 50 lb f .

44 . The gypsum panel of claim 31 , wherein the gypsum panel has a flexural strength of from 20 lb f to 30 lb f .

45 . The gypsum panel of claim 31 , wherein the air voids have an average air void size of 200 microns or more.

46 . The gypsum panel of claim 31 , wherein the air voids have an average air void size of 300 microns or more.

47 . The gypsum panel of claim 31 , wherein the gypsum core comprises a starch in an amount of greater than 0 wt. % to less than 4 wt. % based on the weight of gypsum.

48 . The gypsum panel of claim 31 , wherein the gypsum core further comprises a glass filler.

49 . The gypsum panel of claim 31 , wherein the gypsum core includes a first gypsum core layer and a second gypsum core layer, the first gypsum core layer having a density greater than the second gypsum core layer and a thickness lass then the second gypsum core layer.

50 . The gypsum panel of claim 49 , wherein the first gypsum core layer comprises a glass filler.

51 . A method of making a gypsum panel, the method comprising:

providing a first facing material,

providing a gypsum slurry comprising stucco, a foaming agent, optionally starch in an amount of less than 4 wt. % based on the weight of stucco, and water onto the first facing material,

providing a second facing material onto the gypsum slurry, and

allowing the stucco to set;

wherein the gypsum panel has a density of 33 pcf or less, a weight of 1,800 lbs/MSF or less, and an NRC value of 0.2 or more.

52 . A gypsum panel comprising a gypsum core and a facing material,

the gypsum core comprising gypsum, a foaming agent, and optionally starch in an amount of less than 4 wt. % based on the weight of gypsum,

wherein the gypsum panel has a density of 33 pcf or less, a weight of 1,800 lbs/MSF or less, and an NRC value of 0.2 or more.