Abstract: A closure (1) for a beverage container may have a base cap (2) for securing to the container and a detachable over-cap (3) for protecting a valve member (10) providing an outlet through which a beverage can be dispensed. The over-cap (3) has an array of holes (21) providing airways through the over-cap (3) to prevent choking if the over-cap (3) is accidentally swallowed and lodges in the throat in any orientation. The holes (21) are arranged to permit through flow of air in any orientation of the over-cap (3). The over-cap (3) may also be provided with ribs (14) or channels providing airways to allow flow of air around the outside of the cap (3) if swallowed and lodging in the throat.

Abstract: The invention provides a process for the production of sialon ceramic (and a sialon ceramic produced by such a process) comprising or including the steps of: (I) preparing a sialon reactant mixture including or comprising: a) silicon metal; b) clay; and c) a secondary aluminium source; (II) heating the reactant mixture in an atmosphere containing nitrogen gas to a temperature sufficient to substantially react the silicon metal, the secondary aluminium source and the nitrogen with the clay to form or to contribute to the forming of the sialon product; wherein the clay participates in the reaction as a source of aluminium and silicon. Further, the invention provides a method for preparing a sialon ceramic in a predetermined shape.

Abstract: A process for the production of .alpha.' or .beta.'SiAlON from a starting mixture of silicon metal and clay, wherein the process includes heating the mixture in a flowing nitrogen, or nitrogen containing, atmosphere to a temperature sufficient to react the silicon and the nitrogen with the clay to form the .beta.' or .alpha.'SiAlON and wherein the clay participates in the reaction as a source of aluminium and silicon.