Title

"Pre-fϊred base for the firing of ceramic articles"

Field of invention

The present invention relates to the ceramics industry sector and concerns a pre-fired base to be placed under ceramic articles, in particular ceramic sanitary ware, during their firing at high temperatures so as to be subject to a predetermined shrinkage suitable for eliminating the deformation or breakage of it or the ceramic parts placed on it.

Background One of the most important stages in the process of manufacturing ceramic articles, and ceramic sanitary ware in particular, is their firing at a temperature of about 1250 ⁰ C during which the ceramic parts are rested on special bases with the aim of reducing their breakage or deformation following their shrinkage caused by the high temperature of the kiln. Currently the said bases, having the most varied geometric shapes because they depend on the dimensions of the ceramic part under which they must be placed, are made in the same factory that manufactures the ceramic parts and are produced with the mixture used in the ceramic parts.

The bases currently on the market are not pre-fired and therefore, during firing, they are subject to unexpected deformation and to breakage that damages not only the ceramic part placed on them but often also the

surrounding ceramic parts, with the consequence that the manufacturers of ceramic parts must sustain a considerable number of rejects. Another problem with the bases currently on the market is their extreme fragility that causes lengthy times and requires great attention when they are being arranged in the firing kilns in order to prevent them from breaking. Furthermore, to prevent the ceramic parts from sticking to the bases, it is necessary to sprinkle them with alumina using a manual brush method because of their extreme softness, which, besides being a further additional cost, is also the cause of damage due to possible splattering of the alumina onto the surrounding ceramic parts that, if they are splattered, will have to be re-fϊred, with consequent further rise in production costs. Other problems with the current bases concern the large areas that their internal manufacture requires for the location of the plaster moulds and the casting and drying equipment, as well as the use of labour to manufacture them.

Disclosure of invention

It is an object of the present invention to solve the above-mentioned problems by making available to companies that manufacture ceramic parts, and parts of ceramic sanitary articles in particular, a base consisting of a mixture pressed into the required shapes according to the use to which the said base must be put, and pre-fired at a temperature that, during the firing of the ceramic part placed on it, allows them to have a predetermined shrinkage

depending on the part itself and in any case such as to prevent its uncontrolled deformation that generally causes it to break.

It is another object of the present invention to supply the ceramic parts industry with a base characterized by high strength due to it being pressed and pre-fired beforehand.

It is another object of the present invention to supply the user with a base that, due to its structural characteristics, allows production rejects of ceramic articles to be drastically reduced with the consequent reduction in their production costs. It is another object of the base that is the subject of the present patent to have high strength so as to be coated with alumina by its simple immersion in a container of liquid alumina and no longer with the manual brush method. It is another object of the present invention to allow it to be stored in small areas and so free those normally occupied for the location of the moulds and of the casting and drying equipment.

It is another object of the present invention to have bases that are qualitatively homogeneous with identical technical characteristics determined by their pressing and pre-firing processes. It is still another object of the present invention to obtain a base on which to rest ceramic parts with technical characteristics that are superior to similar ones currently on the market.

These and other objects are obtained by the invention that is the subject of the present application that concerns a base to be placed under ceramic articles, in particular ceramic sanitary ware, characterized in that it is pressed beforehand in a mixture that is suitable for withstanding temperatures up to 125O ⁰ C and then pre-fired at a certain temperature so as to have high strength such as to prevent its uncontrolled deformation during firing and such as to favour its predetermined shrinkage according to the structural characteristics of the ceramic part placed on it, so preventing its breakage or deformation, with the consequent advantage for the user of having a reduction in production times and costs.

Detailed description

Further characteristics and advantages of the invention will become more readily apparent from the description of the qualitative characteristics of the base that is the subject of the present application illustrated, by way of non- limiting example, in the only drawing (Fig. 1) that shows the base (1) made with a specific mixture such that it can withstand temperatures suitable for firing ceramic objects, and sanitary ware in particular, up to about 1250 ⁰ C, to then be pressed with pressures suitable for the use to which the base (1) must be put. Depending on its use, the base (1) can be made in different shapes: square to support wall hung sanitary ware; rectangular, like the one shown in Fig. 1 , to

support toilet bowls and bidets, rectangular with appendage for water closet monoblocks and so on.

A further characteristic of the base (1) is that it is pre-fired at a suitable temperature so that during firing it has a shrinkage that is predetermined according to the structural characteristics of the ceramic part placed on it so as to prevent it from breaking or deforming.

The pre-firing of the base (1) also has the function of preventing it from being subject to bursts or breakages during firing that normally damage the ceramic piece placed on it and also the ones surrounding it, with the effect of eliminating or at least considerably reducing production rejects.

Furthermore, the pre-firing of the base (1) gives it high strength with the effect of making it easier to coat it with alumina just by immersion in a container of liquid alumina, all with a saving of time and relevant production costs. The base (1) as characterized above also offers the advantage of requiring very little storage space.

The patent so conceived is susceptible of numerous modifications and versions, all of which fall within the scope of the inventive concept. Furthermore, the materials and dimensions of the invention as described and illustrated in the accompanying drawing and claimed below, can be of any type according to requirements.