Coating processes – Nonuniform coating – Applying superposed diverse coatings or coating a coated base
Patent
1995-09-02
1999-05-04
Beck, Shrive
Coating processes
Nonuniform coating
Applying superposed diverse coatings or coating a coated base
427266, 427269, 4273762, 427379, B05D 138, B05D 302
Patent
active
059002808
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
This invention relates to the treatment of the ceramic and other earthenware bodies, and is particularly but not exclusively concerned with the treatment of fired clay bodies in the form of ceramic garden or patio pots. Other applications include hanging pots, wall hangers, house bricks and ceramic roof tiles, or any other ceramic, fired clay or earthenware article.
One particular problem associated with ceramic pots and containers intended for use outdoors eg in gardens, patios and on walls, is the tendency towards damage due to the action of frost. It is a well-known fact that when water is absorbed into the walls of porous earthenware pots, freezing temperatures will case that water to expand and the pots will often crack, laminate, effloresce or simply fracture.
Attempts have been made in the past to obviate this problem by making surfaces of the pot water repellent or waterproof, eg by glazing. If the glaze is applied while there is still some moisture in the earthenware then freezing temperatures will nevertheless have the same detrimental effect on the ware. Further, it has been found that because of the environment in which garden or patio pots are used and located, damage is often suffered by; the glaze, allowing ingress of water or moisture which is acted upon by the freezing temperature so that expensive and attractive pots are damaged and often destroyed.
Some earthenware pots are decorated by decalcomania transfers or by hand painting, the decoration being then fired onto the surface. It is preferred that the surface area of the pot where the transfer or paint is to be applied is smooth and for this reason the surface is sometimes glazed before applying the transfer or other art work. This process involves an additional firing which adds to the cost of the decorated ware.
It is an object of the invention to provide a method of treating ceramic or other earthen ware that does not suffer from some or all of the above disadvantages and which results in a pot which reduces the damage by reason of freezing temperatures acting on the ware, and/or to provide improvements generally.
A further alternative object is to attempt to provide a method of treating earthen ware and the like to enable it to be more receptive to decals or other decoration without the need for glazing the ware before decorating it.
A further alternative object includes attempting to provide ceramic or other earthen ware which does not suffer from the known limitations and faults of ware produced by conventional processes.
SUMMARY OF THE INVENTION
According to the present invention there is provided a process of impregnating a fired earthenware body and a product made by that process, as claimed in the accompanying claims.
In one embodiment, a method of treating a fired earthenware body comprises treating the body with a liquid medium comprising a water-repellent constituent such as silicone, drying the body so as to leave the water-repellent constituent within the pores of the body, whereby resistance to entry of water and subsequent freezing is improved.
In the embodiment, the step of drying the body is preferably carried out at a raised temperature below 200.degree. C., whereby the rate of drying is increased, but degredation of the silicone or other water-repellent material is minimized. In the embodiment, pressure may be applied to cause the water-repellent medium to more thoroughly permeate the porous structure of the earthenware.
In another embodiment, an earthenware body is provided with enhanced ability to receive a decal or transfer or other decorative element by treatment with a liquid medium such as a silicone-containing liquid medium (in the form of a solution in a solvent, or a dispersion or emulsion in water, for example). In this way, it has been found, surprisingly, that the necessity for the provision of a glazed surface for the satisfactory application of decals and the like is avoided. Surprisingly, after treatment with a silicone-containing liquid medium, and subsequent drying,
REFERENCES:
patent: 3895136 (1975-07-01), Makishima et al.
patent: 3904791 (1975-09-01), Iverson et al.
patent: 4293599 (1981-10-01), Hori et al.
patent: 4315790 (1982-02-01), Rattee et al.
Wensley, Doug Pottery A Guide to Advanced Techniques Crowood Press, 1995, pp. 89, 91, 122-123.
Beck Shrive
Chen Bret
LandOfFree
Treating earthenware bodies does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Treating earthenware bodies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Treating earthenware bodies will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1868897