Abstract: A mirror assembly comprising a glass substrate, a low transmissivity reflecting coating on the substrate and an opacifying member which is assembled adjacent to the glass substrate for a front surface mirror or the reflecting coating for a back surface mirror. The present invention also provides a method of producing a mirror assembly comprising depositing onto a hot ribbon of glass during the production process a low transmissivity reflecting coating and assembling an opacifying member adjacent to the glass substrate or the reflecting coating of the mirror so formed.

Abstract: Glass is thermally treated by contacting the glass with a gas-fluidized particulate material of non-compacted particle structure which is such that the apparent density of the particles is less than the actual density of the material forming the particles. The buoyant particles constitute a gas-fluidized bed in a quiescent uniformly expanded state of particular fluidization, and the material of the particles and the temperature of the bed are selected so that the heat transfer coefficient of the bed is sufficient to produce a desired thermal treatment, for example thermal toughening of hot glass.

Abstract: A fluidized bed for the thermal treatment of glass articles is maintained in a quiescent uniformly expanded state of particulate fluidization by establishing a high pressure drop across a porous membrane through which fluidizing gas is supplied to the bed, of at least 60% of the pressure at which the fluidizing gas is supplied to a plenum chamber beneath the membrane.

Abstract: The thermal treatment of glass is effected by heat transfer between the glass and a gas-fluidized particulate material which is in a quiescent uniformly expanded state of particulate fluidization. Glass sheets are thermally toughened by immersing each glass sheet, which is at a temperature above its strain point, in the gas-fluidized bed prior to the immersion of the glass in the bed.