SHAW EDWARD (GB)
GALLIMORE JOHN MICHAEL (GB)
SHAW EDWARD (GB)
| US3818087A | 1974-06-18 | |||
| US3623713A | 1971-11-30 | |||
| DE3816892A1 | 1989-06-15 | |||
| US4432798A | 1984-02-21 |
| 1. | An item of kiln furniture, formed of a composition including a lithium compound. |
| 2. | An item according to Claim 1, containing 2% to 25% by weight of the lithium compound. |
| 3. | An item according to Claim 2, containing about 10% of the lithium compound. |
| 4. | An item according to any preceding Claim, wherein the lithium compound is lithium oxide. |
| 5. | A method of firing a ceramic kiln, the method comprising mounting the article on a support item of kiln furniture formed from a composition including a lithium compound, and then firing the article in the kiln. |
| 6. | A method of making an item of kiln furniture comprising mixing a refractory component, a binder and a lithium compound, adding water to form a granulate, pressing an article, drying and firing the shape. |
| 7. | A method according to Claim 6, wherein the lithium compound makes up 2% to 25% by weight of the mixture. |
| 8. | A method according to Claim 7, wherein the lithium compound comprises 10% by weight of the mixture. |
| 9. | A method according to Claims 6 to 8, wherein the lithium compound is petalite or spodumene. |
| 10. | A method according to any of Claims 6 to 9, wherein the refractory component is alumina and the binder is ball clay, and magnesium carbonate is added. |
During firing of ceramic articles, e. g. tableware in a kiln there is a tendency for the ceramic articles to stick to the supporting item of kiln furniture. Normally this is resolved by applying some type of coating material. This is usually sprayed and needs reapplying at intervals. It is one object of this invention to reduce and ideally eliminate the need for any coating.
According to the invention in one aspect there is provided an item of kiln furniture, formed of a composition including a lithium compound.
According to the invention in another aspect there is provided a method of firing a ceramic article in a kiln, the method comprising mounting the article on a support item of kiln furniture formed from a composition including a lithium compound, and then firing the article in a kiln.
The lithium compound may be a simple derivative such as lithium oxide. It is preferred that the lithium compound is a lithium aluminosilicate, more preferably it is petalite Li20 Ai203. 8SiO2 and/or spodumene (Li20 Al203. 4Si02). Mixtures may be used.
The item is made from a composition including the lithium compound. Preferably the proportion of the lithium compound is between 2% and 25% by weight, preferably about 10% by weight.
The composition preferably comprises a particulate refractory component, and a binder.
The refractory component may be a refractory oxide, carbide, nitrite, boride, silicate, examples being alumina, silicon carbide, cordierite, magnesia, mullite, zirconia; or the like. The binder may be ball clay or the like.
Other ingredients may be present in the composition provided that they do not mar the effectiveness of the item. For example, refractory fibres such as alumina fibres, alumino silicate fibres, calcium silicate fibres, silicon carbide whiskers; and the like may be present.
To prepare the item the dry ingredients of the composition are mixed, water is added, and the resulting granulate is pressed with metal dies to form the desired shape. This is then dried and fired.
The article of kiln furniture may be any type of support, spacer, batt, profile setter, cup ring or the like.
In order that the invention may be well understood it will now be described by way of illustration with reference to the following example in which parts are by weight.
Example I The following were mixed together: alumina 40 ball clay 33 magnesium carbonate 17 petalite 10 100 Water is added to form a granulate which was pressed in metal dies to form an item of kiln furniture. The shaped item was used to support a cup when that was fired. The assembly of cup and support were subjected to firing in a kiln. The cooled assembly was removed from the kiln and there was no sticking of the cup to the support.