FR2647706A1 - Method for obtaining coating elements restoring the appearance of eroded stone and elements thus obtained - Google Patents

Abstract

The method consists in preparing the interior surface of a mold 1 by depositing thereon a layer 4 of pulverulent or granular material then a first pulverulent film 5 conveying a dye, and a second pulverulent film 6 to at least partially neutralize the effects of the dye, then filling the mold 1 with a liquid or pasty mortar. After demoulding, the elimination of the base layer 4, for example by brushing, gives the element the appearance of worked stone and eroded by time.

Description

The present invention relates to coatings restoring the

  the natural physiognomy of natural stone, worked and eroded, which is reported for pure aesthetic purposes in new works or, in order to restore the original appearance, on old buildings such as walls , pillars, columns, arches, or others

architectural works.

  There are a number of plate-shaped products available on the market to simulate massive natural stone. These, obtained industrially by molding rock powder mixed with a binder, offer a very poor diversity for the user

  demanding, seeking to obtain the authentic and imposing appearance of

  ancient tructions by the size and variety in the color shades of the original stones. We only find small elements with contours always identical because standardized, and having surface conditions, both geometrically and in terms of colors, almost uniform, which, after implementation, gives the surfaces thus coated with a monotonous and somewhat artificial appearance, in particular by the total absence of a varied erosion and, in particular, for stones of angle or pillars visible on at least two sides, stones in which the choice in elements of coating is, by

  elsewhere, if not nonexistent, at least extremely limited.

  The present invention aims to eliminate all these disadvantages and relates to a method for obtaining coating elements restoring the appearance of natural stone worked, aged, including its wear, erosions and other outrages time. It also covers

  coating elements obtained by this process.

  The technical result of the invention being to restore

  the actual appearance of the originally primitively worked and subsequently altered stone

  erosion and other outrages of time, a mold is used which corresponds to the exact appearance of the new smooth-surfaced stone, as it is supposed, at the time of its use, to have left the hands of the worker, then the bottom and / or the other walls of this mold are prepared to restore the traces of the erosion undergone by the stone during

its aging.

  Mechanical erosion is characterized by wear and loss of material that result in hollows, the bottom of the mold is first prepared by depositing a layer of powder or granular material that will constitute reserves or reliefs that will end up to the surface of the molded material, after removal of the powder material, for example by brushing, or jet of fluid (water or air) or by suction

  in the form of cavities, especially as it is common, against

  puille, aspect that according to the state of the art, it has not yet been able to reproduce. To restore the colorful aspect of the aged stone, we have

  then on the granular pre-layer a pulverulent film of

  to which will be added one or more dyes. Talc, loaded for example with

  full of metal oxides, lends itself well to this use.

  The low density of the talc relative to the oxides allows, by mixing them in proportions of about 2/3 of talc and 1/3 of oxides to facilitate a dispersion of the dye on the mold at the moment

  dusting and attenuate the strong coloring power of the oxides.

  If the mortar constituting the finished stone was molded on a mold bottom having only a dusting of pure oxides, one would obtain concentrated and too violent coloring effects.

  giving an artificial appearance to the finished stone.

  Also before molding, will one deposit on the first powder coating

  slow, vehicle dyes, a second layer less dense and neutral from the point of view coloring. This will mitigate the effects of the previous partially neutralizing them, as opposed to a massive transfer of dyes to the wet mortar during molding. A neutral talc, so white,

  which will be in direct contact with the fresh mortar lends itself well to this

  tion. Where talc is present and according to its thickness, the migration of olorants to the motier will be more or less hampered. Where otherwise it would be absent, the dye transfer will be maximal. Moreover, this second powdery layer, in addition to its screen function with dyes,

  also plays the role of mold release agent.

  This neutral layer having been deposited, it is possible to proceed to the molding itself and in a completely conventional manner. After demolding, the powdery or granular material of the base layer e mold, because of its nature, can be removed by simple brushing or jet of fluid

  or by aspiration which, as already mentioned, makes many cavities against

  skin, characteristic in particular of the effects of erosion by agents

  atmospheric, wind erosion in particular.

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  The invention is explained in more detail in the description which

  FIG. 1 is a perspective view of a mold for the production of a planar element according to the invention, FIGS. 2 and 3 illustrate the following: FIG. respectively two successive phases of the preparation of the mold of Figure 1 before operating the casting of the

  material to constitute the element.

  Although applying to any shape and mold material,

  the invention is explained with reference to obtaining a coating element

  flat, that is, of the simplest form.

  The mold 1 shown in Figure 1 consists of a panel

  planar bottom 2, in any suitable material, for example of agglomerated material

  Méré, strips 3 attached to the upper surface defining a fully closed frame laterally and open upwardly, preferably with a slight relief to promote the subsequent demolding of a manufactured element. The height of these rods 3 forming the frame determines the maximum thickness of the coating element that will be made in the mold.1. The mold 1 disposed at least approximately flat, sees, as shown in Figure 2, its bottom 2 undergo a first phase of preparation for molding. In order to obtain later the appearance, in any case of the surface condition, of a real eroded stone, a projection is made mechanically or manually of a layer 4 locally more or less important. a pulverulent mixture and / or

granular, on the bottom 2.

  The particle size and the composition of the mixture depend on the desired finish for the surface of the coating and so as to obtain

  each molding a stone appearance at least slightly different from the others.

  Materials that are particularly suitable for the blending of layer 4 are: sawdust, wet or dry, and / or

  topsoil, wet or dry. These products are particularly suitable

  or jet of fluid or by sucking rement well to their removal by brushing after demolding. Another constitution of the mixture may optionally be chosen according to the

desired particular result.

  In the next phase of preparation of the mold 1, a thin film of pulverulent agent carrying the dye (s) is dusted onto the layer 4, and which will advantageously consist of talc. To do this, the talc must be mixed with the dye (s) -4 which is (are) generally in the form of powdery oxides. In order to obtain a coating element which restores the appearance of limestones of white to yellow hues, it is particularly advantageous to use as yellowish to brown iron oxide or Sienna clay. To obtain on the finished product areas with shades of color different from those of the entire surface, then depositing a second film 6, by gently sprinkling, in the places and in the directions chosen, neutral or also powdery white agent or granular. Depending on its local density, this layer 6, as mentioned above, will serve as a selective screen for the transfer of the dye (s) to the mortar which will be subsequently cast so as to give its surface localized shades of more or less intensity. attenuated, consistent with those of the original natural stone and also naturally

  aged. This layer also promotes subsequent demolding.

  The bottom 2 of the mold 1 thus prepared is ready to receive, in the form of a pasty mortar, the material which, after solidification and

  drying, will be the desired coating element.

  The mortar can then be poured into the mold 1, as in any molding practice mastered by those skilled in the art, and equalized with a spatula or trowel. This phase, quite usual,

is not illustrated.

  The mortar is advantageously constituted by a mixture of powder or grains of rock, a binder, for example a resin or a hydraulic binder, and water, which can be considered as known per se, and

  does not cause any particular problem.

  After solidification and drying, the coating element x3u fluid jet or pa aspirao2 can be demolded and, after brushing to eliminate the particles oe first primer layer 4, granular or powder, and which puts the surface of the stone bare with all its cavities or crevices, even

  undercut, be stored before use.

  What has just been said applies without any problem to flat plan elements of low or relatively modest surface area. For larger surfaces and to ensure better mechanical strength and less fragile impact during subsequent manipulations, it is

  advantageous to drown in the element during molding an armature.

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  From the foregoing description, it can be seen that by the preparation

  the bottom of the mold, each element of coating will be original, can not be identical to any other because the eye will always perceive differences, as it is the case with natural stones worked and eroded, even of texture nearby or of the same origin . Moreover, the process allows the reconstruction of the appearance of any kind of stone by the choice of mortar components, as well as custom and on demand, even for the coating of structures such as ceilings, vaults, crossed ogives, columns, pillars,

arches, etc ...

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R E E N D I C A T I ONS

  1 .- .. Process for the production of architectural coating elements rendering the appearance of the worked and eroded natural stone, characterized in that it consists in: - using a mold (1), preparing the inner surface of the mold (1) by depositing thereon a layer (4) of powdery and / or granular material, then successively, a first film (5) of pulverulent agent carrying at least one dye, then a second film; (6) pulverulent agent at least partially neutralizing the effect of the dyes by selective screening according to its local thickness to the transfer thereof to the subsequently deposited mortar, - to fill the mold (1) with a mortar liquid or pasty, - after solidification of the mortar, to unmold the coating element produced. 2. Process according to claim 1, characterized by the fact

  that the layer (4) consists of wet or dry wood sciurc.

  3. Process according to claim 1, characterized by the fact

  that the layer (4) consists of dry or wet topsoil.

  4. A process according to claim 1, characterized in that the layer (4) consists of a mixture of sawdust and

  dry or wet topsoil.

  5. A process according to any one of claims 1 to 4,

  characterized in that the agent film (4) consists of

  talc carrying the dye (s).

  6. A process according to any one of claims 1 to 4,

  characterized in that the second powdery film (6) is

also made of talc.

  7. A process according to any one of claims 1 to 6.

  characterized by the fact that after demolding, the pulverulent material or

  granular material (4) is removed by brushing.

  8. Process according to any one of Claims 1 to 6,

  characterized by the fact that after demolding, the pulverulent material or

  granular material (4) is removed by fluid jet.

  9. A process according to any one of claims 1 to 6,

  characterized by the fact that after demolding, the powdery material or

  granular material (4) is removed by suction.

  10.- Coating element obtained by the process according to one

  any of claims 1 to 9.