Abstract: A method for forming shaped articles from glass fiber reinforced gypsum. An aqueous slurry of calcium sulfate hemihydrate, water and glass fibers contains between 22 and 45 parts by weight water, 100 parts by weight calcium sulfate hemihydrate and 3 to 10 parts by weight glass fiber. The slurry is provided as a continuous ribbon on a moving, water-impermeable first membrane. A water-impermeable second membrane is applied above the continuous ribbon and sealed along its side edges to the side edges of the first membrane to form a sandwich consisting of the two membranes and the slurry ribbon.The sandwich is shaped prior to the setting of the gypsum and is retained in the desired shape until initial setting occurs. Thereafter at least a portion of one of the two membranes is removed and substantially all of the uncombined water is removed from the shaped ribbon.

Abstract: A method and apparatus for forming shaped articles from glass fiber reinforced gypsum. An aqueous slurry of gypsum hemi-hydrate, water and glass fibers contains between 22 and 45 parts by weight water, 100 parts by weight gypsum hemi-hydrate and 3 to 10 parts by weight glass fiber. The slurry is deposited as a continuous ribbon on a moving, water-impermeable formable sheet which is pre-shaped and thereafter the slurry ribbon is pressed into a desired profile. The formable sheet and slurry ribbon are maintained in the desired profile until the slurry sets. Thereafter the product ribbon is cut transversely into lengths as desired. The formable sheet may be removed before cutting, or may be retained in engagement with the product ribbon during and after cutting to serve as a protective cover for the surface of the article. The process and apparatus are especially adapted to produce liner sheets for building construction panels.

Abstract: A light valve system wherein particulate material is introduced into a normally light-transmitting cavity to restrict light transmission through the cavity from one side to the other. The cavity may be partially or totally filled with a particulate material depending on the degree of light restriction desired. The particulate material may comprise a thermal insulating material which restricts heat transmission as well as light transmission through the cavity. The use of the present light valve system in a greenhouse structure is described.

Abstract: A light transmitting building panel comprising a flat central sheet and upper and lower corrugated sheets secured to the opposite faces of the flat central sheet, thereby to provide a set of upper cells and a set of lower cells. The upper corrugated sheet is laterally offset relative to the lower corrugated sheet whereby each upper cell is positioned intermediate of adjacent ones of the lower cells and whereby heat conduction between the internal and external surfaces of the panel is minimized. The flat central sheet and the upper and lower corrugated sheets are formed from a light transmitting glass fiber reinforced plastic. The present building panel is particularly useful in greenhouses as roof panels and wall panels. The long span capability, the light transmitting characteristic and the unique cell arrangement of the present building panel are advantageously employed in greenhouses.

Abstract: A light transmitting building panel comprising a flat central sheet and upper and lower corrugated sheets secured to the opposite faces of the flat central sheet, thereby to provide a set of upper cells and a set of lower cells. The upper corrugated sheet is laterally offset relative to the lower corrugated sheet whereby each upper cell is positioned intermediate of adjacent ones of the lower cells and whereby heat conduction between the internal and external surfaces of the panel is minimized. The flat central sheet and the upper and lower corrugated sheets are formed from a light transmitting glass fiber reinforced plastic. The present building panel is particularly useful in greenhouses as roof panels and wall panels. The long span capability, the light transmitting characteristic and the unique cell arrangement of the present building panel are advantageously employed in greenhouses.

Abstract: Apparatus for forming shaped articles from glass fiber reinforced gypsum. An aqueous slurry of calcium sulfate hemihydrate, water and glass fibers contains between 22 and 45 parts by weight water, 100 parts by weight calcium sulfate hemihydrate and 3 to 10 parts by weight glass fiber. The slurry is provided as a continuous ribbon on a moving, water-impermeable first membrane. A water-impermeable second membrane is applied above the continuous ribbon and sealed along its side edges to the side edges of the first membrane to form a sandwich consisting of the two membranes and the slurry ribbon.The sandwich is shaped prior to the setting of the gypsum and is retained in the desired shape until initial setting occurs. Thereafter at least a portion of one of the two membranes is removed and substantially all of the uncombined water is removed from the shaped ribbon.