POROUS CLAY POTTERY CONTAINER WITH VOLATILE FLUID

Abstract: A hollow clay pottery container (10) having an opening (14) characterised in that the hollow clay pottery container (10) has an outer wall (12), contains a quantity of active fluid (22), the opening is sealed, the clay pottery of the container has been fired at a temperature below the vitrification point of the clay so that the clay pottery is permeable to vapour emitted from the active fluid (22) and the container (10) is arranged so that the vapour can permeate through the outer wall (12) thereof.

Description: TITLE POROUS CLAY POTTERY CONTAINERWITHVOLATILE FLUID DESCRIPTION The present invention relates to containers. FIELD OF THE INVENTION It is known to manufacture hollow containers of clay or similar material. In particular, hollow containers are often formed from stoneware clay or other clay, by hand. The containers are normally small in size but they can be made to any desired size or shape. The formed clay containers are dried in known manner using methods which are well known in the pottery art. Subsequently the dried articles are fired to turn them into articles of pottery. SUMMARY OF THE INVENTION The firing is, in accordance with the present invention, arranged so that the pottery has a required capillarity. If the pottery is fired at a temperature which is too high then it becomes impermeable to vapour. On the other than, if the pottery is fired at a temperature which is too low then it may be excessively porous. In accordance with one aspect of the present invention there is provided a hollow clay pottery container having an opening, wherein the hollow clay pottery container has an outer wall, contains a quantity of active fluid, the opening is sealed, the clay pottery of the container has been fired at a temperature below the vitrification point of the clay so that the clay pottery is permeable to vapour emitted from the active fluid and the container is arranged so that the vapour can permeate through the outer wall thereof. DESCRIPTION OF THE INVENTION The active fluid used in the present invention is usually a liquid. Further, the active fluid can take many forms but it is particularly envisaged that it will be a fragrance or an insect repellant. In the case of a fragrance the active fluid may be an essential oil but it would be possible to use an artificial synthetic fragrance. Preferably, the fragrance is oil based but it could have an aqueous base and be thickened with a suitable material such as paraffin oil and talc powder. A wide range of clays can be used in the present invention. " The vitrification point of clays varies considerably. For example, pocelain has a vitrification point of about 1260° - 1500 β C, stoneware clay has a vitrification point of about 1350°C but this can be as low as 1100 β C for some stoneware clays, while earthenware clay has a vitrification point which is usually around 950° - 1100°C depending on the type of clay. The firing temperature needs to be below the vitrification point such as less than 100°C below this point preferably between 10 and 50 β C below this point. If the firing temperature is too low, then the container is too porous and liquid can escape. Also, the preferred firing temperature varies with the viscosity of the active fluid. For example, a container containing lemon essential oil i preferably has a firing temperature of 1280°C in a stone¬ ware clay having a vitrification point of 1300 β C, whereas in the same clay a rose essential oil containing container preferably has a firing temperature of 1260°C. 5 - This is because the rose essential oil is more viscous than the lemon essential oil. The lower firing temperature leads to larger capillaries in the finished product. In the firing step, it is essential that the container 10 being fired reach the required temperature. It can be held at the temperature for as long as desired and this time is not critical. It can be, for example, up to five minutes or up to thirty minutes, or for any length of time which completes the desired processes. 15 The pottery container of the present invention contains capillaries through which vapour emitted from the active fluid can escape but not otherwise. Thus, the rate of release of the vapour from the container is controlled by the degree of capillarity of the 20 pottery. Essentially, the container is liquid tight, although in hot weather the capillaries may open up a little and a small amount of liquid can seep out. Whilst a wide range of different pottery clays can be 25 used to manufacture the product of the present invention, it has been found that stoneware clay gives very satisfactory results. The container may be glazed externally for visual appeal but it is essential to leave some of the pottery 30 unglazed to avoid blocking all of the capillaries of the C PΪ pottery. Typically, the underside of the container and/or part of the side thereof is left unglazed. Preferably, the outer wall has a thickness in the range from 3 to 30 mm, more preferably in the range from 5 to 15 mm. The product of the present invention may be used for deodorising rooms where it contains a fragrance, or in cupboards to repell silverfish and other insects where it contains insect repellant. The container emits a vapour continuously over an extended period of time through the capillaries in the pottery. The present invention will now be described, by way of example, with reference to the accompanying drawing which is a vertical sectional view of a hollow clay pottery container in accordance with the present invention. In the drawing, there is shown a hollow clay pottery container 10 which is formed of stoneware clay and has an outer wall 12 and an opening 14. As shown, the opening 14 is closed by a plug 16 and a quantity of sealant 18 is applied around the opening 14 and the plug 16 to ensure that the opening 14 is sealed. The outer wall 12 has a base portion 20 to enable the container to rest on a flat horizontal surface. Further, the stoneware clay of the outer wall 12 has been fired at a temperature less than 100 β C below the vitrification point of the clay so that it is permeable to vapours emitted from a quantity of fragrant essential oil or other active fluid 22 in the container 10. Further, a portion of the outer wall 12 may have a -A glazed layer 24 applied to it for decorative purposes. However, it is essential that a portion of the outer wall be unglazed to enable the vapour to permeate through the outer wall 12. 5 In the embodiment shown an upper portion of the wall 12 of the container 10 is glazed on its outer face while a lower portion and the base 20 is left unglazed. In use, it is found that a container 10, as shown in the drawing, with a wall thickness between 5 and 15 mm 10 can emit vapour from the active fluid for a period of several months. Subsequently, the container 10 can be used as a decorative ornament. Modifications and variations such as would be apparent to a skilled addressee are deemed within the scope of 15 the present invention.

Claims: CLAIMS 1. A hollow clay pottery container having an opening, characterised in that the hollow clay pottery container has an outer wall, contains a quantity of active fluid, the opening is sealed, the clay pottery of the container has been fired at a temperature below the vitrification point of the clay so that the clay potter is permeable to vapour emitted from the active fluid and the con¬ tainer is arranged so that the vapour can permeate through the outer wall thereof. 2. A container according to claim 1 characterised in that the active fluid is a fragrance. 3. A container according to claim 1 or 2, characterised in that the active fluid is a liquid. 4. A container according to claim 3, characterised in that the active fluid is an essential oil. 5. A container according to any one of the preceding claims, characterised in that the clay pottery of the container has been fired at a temperature less than 100 β C below the vitrification point of the clay. 6. A container according to claim 5, characterised in that the clay pottery of the container has been fired at a temperature between 10 and 50°C below the vitrification point of the clay. 7. A container according to any one of the preceding claims, characterised in that it is formed of stoneware clay. 8. A container according to any one of the preceding claims, characterised in that the outer wall has a thickness in the range from 3 to 30 mm. 9. A container according to claim 8, characterised in that the outer wall has a thickness in the range from 5 to 15mm.

Inventors: ALACS ANNA ILDIKO, ALACS LES, NAGY ZSUZSANNA, SZABO ZOLTAN, ALACS, ANNA, ILDIKO, ALACS, LES, NAGY, ZSUZSANNA, SZABO, ZOLTAN
Applicants: ALACS ANNA ILDIKO, ALACS LES, NAGY ZSUZSANNA, SZABO ZOLTAN, ALACS, ANNA, ILDIKO, ALACS, LES, NAGY, ZSUZSANNA, SZABO, ZOLTAN
Application year: 1984
Main classification: A61L9
IPC codes: A61L9