The invention relates to a process for the avoidance of burrs when demoulding reconstructed stone and decorative panels, as well as finished products - reconstructed stones and decorative panels without burrs - obtained through this process.

There is known the standard process for the manufacture of the reconstructed stone and the decorative panels, which includes the following steps: a) assembling the natural stone slabs to a suitable size in order to be handled - for example, maximum 1 m/1 m, so as to obtain, on one side, the surface with the desired pattern; b) impregnating the surface with the desired pattern in a plastic mass that can take in-depth the specific spatial contour of the natural stone - for example silicone rubber - in order to obtain the negative mould 1 ; c) in the negative mould 1 a plastic mass different from that of the negative mould 1 is poured, having the same rendering qualities of the surface pattern on which it is poured, resulting one or more positive moulds 1, which reproduce/render, almost identically, the surface of natural stone slabs; d) with the positive mould 1, a plastic mass of the same material as that of the negative mould 1 , or another plastic mass having similar qualities to it, is impregnated at a certain temperature, in order to obtain one or more negative moulds 2, having a thickness between 2 - 10 centimetres; between the negative moulds 2, there are 1-2 cm decks; e) in the negative mould/moulds 2 the mixture of cement, plaster, etc. is poured, which is pressed with a press whose entire surface (of contact with the cement or plaster mixture) is substantially porous; By strengthening the mixture, identical reconstituted stone tiles and decorative panel tiles are obtained. It appears, therefore, a significant disadvantage of the process: given that by casting and natural drying the edges between the contour surfaces and the rear conventional surface are irregular, most often exceeding the maximum size of t j _, obtained tile, and these edges of the surface substantially porous are to be adhered to the wall, wall, etc., the irregular edges distance the tiles between them, leaving joints of 0.5 - 5 mm, that are not permitted at the assembly; as a consequence, immediately after the cement/plaster mass has been strengthened, an activity of manual cutting of these edges follows, a meticulous and difficult to control process.

There is also known the process of "drumming", used on small pieces of metal, obtained by stamping, having sharp edges; hundreds of pieces are placed into an enclosure, called a "drum", which is rotated mechanically for a period of time. The sheet metal inside rubs together, while cutting the sharp edges. The disadvantage of this engineering procedure is that it cannot be applied to cement and plaster parts, especially to large ones.

The technical problem solved by this invention is the use of a process that allows: i) to obtain directly by casting and drying, reconstructed stones and decorative panels without burrs, having the edges bevelled evenly and along the entire contour of the piece; ii) to increase the adhesion degree of the reconstructed stone slabs and the decorative panel slabs on the wall, wall, etc., as the soldering material (plaster) also enters the joints of the bevelled edges.

The process of avoiding burrs when demoulding the reconstructed stone and the decorative panels solves the technical problem stated, so that, compared to steps a), b), c), d) and e), it comprises the steps a), b), c'), d') and e'), thus: a) assembling the natural stone slabs to a suitable size so that they can be handled - for example, maximum 1 m / 1 m - so that, on one side, the surface is obtained with the desired pattern; b) impregnating the surface with the desired pattern in a plastic mass that can take in-depth the strips, the grooves, etc. specific to the natural stone - for example silicone rubber - to obtain the negative mould 1\ c ') in the negative mould 1 a plastic mass different from that of the negative mould 1 is poured, having the same rendering qualities of the surface pattern on which it is poured, obtaining one or more positive moulds 1 , which reproduce/render, almost identically, the surface of natural stone slabs; the edges between the contour surfaces and the conventional rear surface, on the contour, are approx. 10 mm x 45°; d ') with the positive mould 1, it is impregnated at a certain temperature, a plastic mass of the same material as that of the negative mould 1, or another plastic mass having similar qualities to it, in order to obtain one or more negative moulds 2, having a thickness between 20 - 100 mm; between the negative moulds 2 , there are 10 - 50 mm decks which, on the contour, will have from the moulding an inner shoulder of approximately 2-10 mm x 45°; e ') in the negative mould/moulds 2 the mixture of cement, plaster, etc. is poured, which is pressed with a press whose entire surface (of contact with the cement or plaster mixture) is substantially porous; by strenghting the mixture, identical reconstructed stone tiles and identical decorative panels are achieved, having the chamfering of approximately 2 - 10 mm x 45° on the contour; Due to the elasticity of the material of the negative mould/moulds 2, the slabs will be easily removed from the mould, without this/these deforming, or breaking.

The advantages of this invention consist in the fact that, using the process of avoiding burrs when demoulding the reconstructed stone and decorative panels: i) they are obtained directly by casting and drying, reconstructed stones and decorative panels without burrs, having the edges evenly bevelled and along the entire contour of the part; ii) the adhesion of the reconstructed stone slabs and the decorative panel slabs on the wall, wall, etc. increases, because the soldering material (plaster) also enters the joints of the bevelled edges; iii) the execution time of the finished parts is considerably reduced, and the cost per unit of processed part is decreased accordingly.

The invention also refers to the following figures that represent:

- figure 1 - view on the positive mould 1, which almost identically renders the surface of the natural stone slabs;

- figure 2 - view on the negative mould 2; the figure has four negative moulds 2, having 10 - 50 mm decks which, on the contour, will have an inner shoulder of 10 mm x 45°;

- figure 3 - section A-A of figure 2; we notice the 10 - 50 mm deck which, on the contour, has by casting an inner shoulder of 10 mm x 45°;

- figure 4 - reconstructed stone, that has; a) a previous conventional surface, with the pattern reproduced by natural stone; b) a substantially porous rear conventional surface that is placed back on the wall and in contact with the binder; c) a finely processed contour surface from the casting; d) approximately 2 - 10 mm x 45o on the contour at the edge between the finely processed contour surface and the conventional porous rear surface. According to the invention, the process of avoiding burrs when demoulding the reconstructed stone and the decorative panels comprises the following stages: Step

1 , selecting the type of reconstructed stone or decorative panel to be multiplied; Step

2, the assembly of natural stone slabs to a suitable Size so that they can be manipulated - for example maximum 1 m / 1 m - so that, on one side, the surface with the desired pattern is obtained; Step 3, impregnating the surface with the desired pattern in a plastic mass that can take in depth the strips, the grooves, etc. specific to the natural stone - for example silicone rubber - in order to obtain the negative mould 1\ Step 4, in the negative mould 1, a plastic mass different from that of the negative mould 1 is poured, with the same rendering qualities of the surface pattern on which it is poured, resulting one or more positive moulds 1 (fig. 1), which render/reproduce almost identically the surface of the natural stone slabs; the edges are bevelled from the inside, on the contour, about 2 - 10 mm x 45°; Step 5, with the positive mould 1, is impregnated at a certain temperature, a plastic mass of the same material as that of the negative mould 1 , or another plastic mass having similar qualities to it, in order to obtain one or more negative moulds 2 (fig. 2), having a thickness between 10 - 100 mm; between the negative moulds 2 there are 10-50 mm decks which, on the contour, have an inner shoulder of 1Ό mm x 45° (fig-3). Step 6 in the negative mould/moulds 2 pour the mixture of cement, plaster, etc., which is pressed with a press whose entire surface (of contact with the cement or plaster mixture) is substantially porous; By reinforcing the mixture, identical reconstructed stone tiles (fig. 4), and identical decorative panel tiles are obtained, which will have; a) a previous conventional surface, with the pattern, reproduced of natural stone; b) a significantly porous rear conventional surface that is placed on the wall and comes into contact with the binder; c) a finely processed contour surface by casting;

d) the chamfering of 2 - 10 mm x 45° on the contour at the edge between the finely processed contour surface and the conventional porous rear surface. Due to the elasticity of the material of the negative mould/moulds 2, the slabs will be easily removed from the mould, without this/these deforming, or breaking; Step 7, control, packaging of finished parts and storage.

According to the invention, by carrying out the process, finished products are obtained - reconstructed stone and decorative panel - without burrs, directly by moulding and drying, having the edges between the contour surfaces and the conventional rear surface evenly bevelled and along the entire contour of the part, resulting, on the one hand, the increased degree of adhesion of the reconstructed stone slabs and the decorative panel slabs on the wall, mural, etc., because the soldering material (plaster) also enters the joints of the recessed edges, and on the other hand, the execution of the finished parts is considerably reduced, resulting in a cost per unit of processed part decreased accordingly.