Process for producing tubular ceramic structures

A process for producing tubular ceramic structures which comprises:

• a) rotating a mandrel-spindle assembly comprising a mandrel component and a spindle component, the mandrel component being a heat shrinkable polymeric tube the eternal surface of which corresponds to the internal surface of the tubular ceramic structure to be produced and the internal surface of which defines a bore, the spindle component being in close fitting but slidably removable contact therewith;
• b) applying a ceramic-forming composition to the external surface of the mandrel component of the rotating mandrel-spindle assembly to produce a tubular ceramic structure the internal surface of which is in contact with the external surface of the mandrel;
• c) removing the spindle from the bore of the mandrel to provide a mandrel-tubular ceramic structure assembly in which the interior surface of the tubular ceramic structure remains in contact with the external surface of the mandrel;
• and,
• d) heat shrinking the mandrel component of the mandrel-tubular ceramic structure assembly to cause the mandrel to undergo shrinkage to a reduced size in which the external surface of the mandrel separates from the interior surface of the tubular ceramic structure facilitating removal of the mandrel therefrom.