Abstract: A method of producing high temperature insulating foam is described. A gellable foam of glass fibre, expanded perlite and bentonite in water is shaped dried and fired at a temperature below the temperature at which a ceramic product is formed but in excess of the temperature at which the bentonite lattice hydroxyl water is lost.

Abstract: The invention provides a method of improving the gastightness of a seal formed between two components consisting of a closure cap applied to seal a container. An ultrasonically vibrating horn is applied to the closure cap to heat the sealing surfaces of the closure cap and container. As the cap and/or container are formed of thermoplastic material, the ultrasonic heating softens the sealing surface of one of the components and causes it to mould into close conformity with the complementary sealing surface of the other component with the effect that the gastightness of the seal between the two is improved. The application of ultrasonic heating energy is discontinued before any significant welding between the two components can occur.

Abstract: A method of preparing a reinforced clay based article is described. A mixture of clay and reinforcement is shaped, dried and then fired at a temperature and for a time sufficient to stabilize the clay against redispersion in water, without forming a ceramic article.

Abstract: An apparatus is disclosed for the continuous manufacture of fiber reinforced plaster sheets which apparatus includes a conveyer for supporting a plurality of sheet casting moulds, a casting station for casting slurry into said moulds and a fiber station at which means are provided for depositing fiber for reinforcement across the surface of the casting slurry. The apparatus also includes a pair of rollers having radial extensions to force the fibers to or adjacent the lower surface of the cast slurry. A second fiber depositing means is also provided for depositing a second batch of reinforcing fibers across the surface of the slurry and a second pair of rollers having an open mesh surface are provided for forcing the second batch of fibers into the slurry to a level at or adjacent the upper surface thereof. The fibers used may be sisal or fiberglas as individual randomly oriented lengths, continuous meandering strands or a random mat deposited over the surface of the slurry.