| 摘要 |
A process for producing tubular ceramic structures (10) of non-circular cross section is provided which comprises: • a) rotating a mandrel-spindle assembly (45) having a non-circular external cross section corresponding to the non-circular internal cross section of the tubular ceramic structure (11) to be produced, the mandrel-spindle assembly (45) comprising a mandrel component (47) and a spindle component (43), the mandrel component (47) being a heat shrinkable polymeric tube of non-circular cross section the external surface of which corresponds to the internal surface of the tubular ceramic structure (11) of non-circular cross section to be produced and the internal surface of which defines a bore (71), the spindle component (43) having a non-circular cross section corresponding to that of the bore (71) of the mandrel (47) and being in close fitting but slidably removable contact therewith; • b) applying a ceramic-forming composition to the external surface of the mandrel component (47) of the rotating mandrel-spindle assembly (45) to produce a tubular ceramic structure (11) of non-circular cross section the internal surface of which is in contact with the external surface of the mandrel (47); • c) removing the spindle (43) from the bore (71) of the mandrel (47) to provide a mandrel-tubular ceramic structure assembly (70) in which the interior surface (75) of the tubular ceramic structure (11) of non-circular cross section remains in contact with the external surface of the mandrel (47); and, • d) heat shrinking the mandrel component (47,76) of the mandrel-tubular ceramic structure assembly (70) to cause the mandrel (47,76) to undergo shrinkage to a reduced size in which the external surface (77) of the mandrel (76) separates from the interior surface (75) of the tubular ceramic structure (11) of non-circular cross section facilitating removal of the mandrel (76) therefrom. |
