Drawbacks of the Prior Art One of the drawbacks of one of the known elements consists in that it has little mechanical and chemical resistance (strength) which limits its use to light constructions.

In order to eliminate this drawback, another type of element has been invented which consists of a cellulose mass, completely impregnated with ceramic. This element has the drawback of high cost, heavy weight and reduced capacity for sound and heat insula- tion.

Objectives of the Invention The objective of the present invention is to provide an inexpensive, very light element with high mechanical and chemical resistance (strength), stability in bad weather situations, and a high capacity for sound and heat insulation.

In order to achieve this objective, the element according to the invention com- prises a solid cellulose foam with ceramic, the cellulose foam being composed of cellulose fibers held together by an adhesive agent, and the ceramic being applied in a localized man- ner to the cellulose foam. The adhesive agent can be, for example, a glue.

The ceramic may be applied either on the surface of the cellulose foam or inter- nally on specific stripes or points. The ceramic is preferabiy configured as a plate, a roll or a cylinder.

In addition, the element may have internal reinforcements, which may preferably consist of, for example, metal plates, wooden plates, cardboard, fabrics, metallic webs, plas- tic webs or segments of wood such as strips of wood and bamboo. The internal reinforce- ments may be arranged in a parallel manner, in a crossed manner or at random.

The element may further have external reinforcements on the surface, preferably comprising plates of metal, wood, plastics or cardboard that are preferably glued on the surface of the element.

In addition, the element may have an impermeabilizing agent on the surface, preferably selected from aluminum sulfide, metal chloride, oils, fatty acids, waxes or indus- trial soaps.

The element may further have fillers to increase volume, preferably selected from kaolin, colophony, sulfur, industrial soaps and calcium sulfide (gypsum).

Thus, the element of the invention is light, has high mechanical resistance (strength), and is composed of a fibrous cellulose foam, agglomerated for instance by a glue, thickened with fillers such as kaolin, sulfur, colophony, hardened by ceramic, (i. e., polymeric silicates, preferably potassium silicate, sodium silicate, or fluorsilicate), and may be internally or externally reinforced.

The element of the invention may be either solid or hollow and presents a broad range of industrial utilization, such as, for instance, in the manufacture of bricks for the civil industry, prefabricated walls, partition-walls, furniture, water reservoirs, packages, cowling (body) of cars, boats and aircraft, where there is the need for light weight, high mechanical resistance (strength) and low cost.

The element according to the invention may be thin, having, for example a thick- ness of about 5 mm, or thick having a thickness of, for instance, about 500 mm or more.

An example, of a composition of a basic element according to the present inven- tion, that is to say, an element without external and internal reinforcements, may consist of the following parameters : i) from 60 to 70% by dry weight of newspaper clippings or other cellulose fibers ; ii) from 20 to 30% by dry weight of anhydrous sodium silicate plus kaolin (or other fillers), wherein the minimum proportion of sodium silicate is 45% with respect to the kaolin (or other fillers) ; iii) from 0 to 10% of poiyviny) acetate (PVA) -based glue or other water-soluble glue, preferably non-toxic and non-inflammable ; and iv) from 0 to 1% of impermeabilizing agents and dyes such as aluminum sulfate, metal chloride, industrial soaps, oils, fatty acids, natural or synthetic waxes.

A Process for Manufacturing an Element A process for manufacturing an element according to the invention may consist, for example, of the following steps : Step a) Prepare a cellulose mass, by using, for example, newspaper remains or other papers, which are defibrated in an aqueous solution or other adequate liquid medium.

The dried mass should preferably have a density of from 1. 15 to 0. 25.

Step b) Eliminate the excess water by pressure or vacuum through a web, pref- erably having 30 mesh. In this step, one achieves the alignment of the cellulose fibers in one or more directions, or at random, depending upon the purpose for which the element is de- signed.

Step c) Add fillers such as sulfur, colophony and kaolin in order to increase the volume of the mass and reduce porosity, and add an adhesive agent such as polyvinyl ace- tate emulsions, latex-based glues or other water-soluble glues. The glue should preferably be water-soluble and nonflammable, or when ignited it should not generate toxic gases.

The addition of adhesive agents also serves to increase the tensile strength of the element, after it has dried.

Step d) Prepare a mold for introducing the cettutose mass, putting internal rein- forcements of the element inside the mold.

As already noted, the internal reinforcements may be plates of metal, wood, cardboard or strips of bamboo, wood, vegetable fibers, webs or iron rods. They serve to in- crease the tensile strength of the element.

When manufacturing prefabricated walls, conduits for electric installation and water tubes may be included at this step.

Step e) Introduce the cellulose mass into the mold.

Step f) Dry the mass outdoors in the open air, in an oven, by hot air, vapor, elec- tric resistance or in any other suitable way.

Figure 1 shows a mold pierced by removable tubes 2, in order to create hollow spaces in the element. Inside these tubes, a flow of hot fluid may be applied such as hot air, or an electric resistance in order to accelerate the process of drying the mass.

It is important to point out that, while drying, the element may undergo contrac- tion of up to 50% with respect to the perpendicular direction of the fibers depending on the percentage of water with respect to the cellulose fibers and the amount of fillers. The more random and perpendicular the arrangement of the fibers among themselves, the lower the contraction while drying and the lower the density achieved. This can be achieved in step"b" of removing the excess water by creating a vacuum in different positions with respect to the mass to be shaped, or by directing the cellulose fibers by a mass-aligning jet through webs before they are shaped. After drying, the cellulose mass assumes the configuration of a solid foam.

Step g) Inject ceramic in a localized manner inside the cellulose mass.

After the ceramic is injected, it may remain in the form of massive plates or cylin- ders inside the cellulose mass in the direction arranged longitudinally, transversely or in the direction of the thickness of the element. Thus, the ceramic remains applied at determined places, whereas in the element known from the prior art the ceramic impregnates it alto- gether, which increases the cost and the weight and reduces the sound and heat insulation characteristics.

As already stated, the ceramic may be selected from, for instance, sodium sili- cate, potassium silicate or fluorosilicate.

Step h) Remove the element from the mold and apply a layer of ceramic with or without fillers throughout its surface. This application is possible, since in this step the ce- ramic is dissolved in a solution (sodium silicate, potassium silicate or fluorasilicate solution), and so, after the solution has dried, the ceramic adheres to the surface of the element.

Step i) Place the external reinforcements on the surface of the element.

The placing of external reinforcements may be preferably carried out by gluing.

As already noted, the external reinforcements may be plates of metal, plastics, formica, wood, cardboard, paper or tissue. The external reinforcements serve to increase the mechanical and chemical resistance (strength), and also to beautify the element.

Alternatively, according to the application of the element, an external reinforce- ment may be not required. Thus, the surface of the element can be impermeabilized.

The impermeabilization may be effected by impregnating the element with one or more impermeabilizing agents such as metallic oxides, synthetic or natural waxes, industrial soaps, oils, fatty acids, inks, varnishes or bitumen.

Optionally, the external reinforcements may be placed on the walls of the mold in step"c"prior to the introduction of the cellulose mass. In this way, while the cellulose mass dries, the external reinforcements adhere to the mass, thereby making step"i"unnecessary.

However, this procedure should only be used if the element does not need any surface layer of ceramic, which may occur depending on the purpose for which the element is designed.

It should be pointed that the process described above details the steps of manufacturing a complete element. Therefore, depending upon the purpose for which the element is intended, some steps may be canceled. For instance, the element may be a brick for civil construction. In this case, it requires only the internal reinforcements (step c) and the surface layer of ceramic (step"h"). In such instance, steps "e", "f' and "i" may be canceled.

It should also be stressed that the above process is only one of the ways of manufacturing the element, and the order of the steps may be modified. Some steps may be suppressed, as already noted, and others may be added. For example, only the cellulose foam may be prepared and, after it has completely dried, it may be mechanically processed (cutting, chipping off, piercing, etc. ), in order to include the internal reinforcements.

Therefore, the process described above only represents a preferred process for manufacturing the element.

The invention also refers to a process for manufacturing panels of solid cellulose and ceramic foam, which is quite suitable for utilization at work locations or for the manu- facture of pieces that are of large dimensions. The process comprises the following steps : Step a) positioning at least one shield, which preferably may be a metal plate, a web, a wooden plate, an isopor (Styrofoam) plate or a masonry wall ; Step b) applying onto the shield the cellulose mass containing fillers and adhe- sive agent by means of mass-sprinkling, either manually or with equipment, such as, for in- stance, a pump ; Step c) applying ceramic, optionally mixed with a filler, onto the cellulose mass ; and Step d) applying a coating, which may be, for example, cement or masonry or a Formica plate, onto the ceramic.

Thus, the process is suitable either for manufacturing walls of houses or build- ings at the site where such houses or buildings are being constructed, or for sound and heat isolation of walls, or else for the manufacture of furniture, water reservoirs or large packages.

The invention further refers to a process for insulating a surface with a solid cel- lulose-ceramic foam, which comprises the following steps : a) applying onto the surface, a layer of ceramic containing a filler ; b) applying onto the ceramic layer a cellulose mass containing fillers and adhe- sive agents by means of mass-sprinkling, either manually or with equipment ; and c) applying ceramic, optionally mixed with a filler, onto the cellulose mass.

This process is quite suitable for insulation at a specific site, for example, a tub- ing of an industrial plant or a masonry wall of a house. The first ceramic layer is only neces- sary on surfaces with high temperature. Thus, in the case of the masonry wall, it is not nec- essary.

The invention will now be described in detail, by way of example, with reference to the accompanying figures.

- Figure 1 is a perspective top view of a mold for the manufacture of an element ; - Figure 2 is a perspective top view of an element manufactured with the mold of figure 1 ; - Figure 3 is a perspective top view of a second element ; - Figure 4 is a perspective top view of a piece made up of two elements ; - Figure 5 is a perspective top view of an element with internal reinforcements; - Figure 6 is a perspective top view of a piece made up of various elements joined to each other ;

- Figure 7 is a perspective internal view of an element with the ceramic injected in strips ; - Figure 8 is a perspective internal view of an element with the ceramic injected at specific points or sites, forming rollers.

Figure 1 shows a mold 1 with removable tubes 2, which serves to create hollow spaces in the element to be manufactured, as well as to accelerate the drying of the cellu- lose mass by passing, for instance, a flow of hot air or water through said tubes. This will substantially reduce the time for drying thick pieces, and will even serve to avoid the use of ovens in such cases. The hollow space created with the removal of the tubes serves to re- duce the weight of the element and to improve the flexibility.

Figure 2 shows en element 3 with hollow spaces 4 manufactured with the mold 1 shown in figure 1.

Figure 3 shows an element 5 in the form of a plate which presents a groove 6 on its surfaces 7. In order to manufacture this element, machines known in the paper industry can be used, as well as rollers to achieve the groove configuration.

Figure 4 shows a piece 8 composed of two elements 9 joined together and made in the form of a plate. This procedure is suitable for obtaining thicker pieces by joining ele- ments.

Figure 5 shows an example of an element with internal reinforcement which in this case consists of rectangular plates 10. The plates 10, as stated before, may be, for ex- ample, of metal, wood or cardboard.

Figure 6 shows a piece 11 obtained by joining elements 12,13, 14 and 15. The elements may be joined to each other by means of glue, rivets, screws, pins or other suitable means. This figure also shows an internal reinforcement 16, inserted between the elements 12 and 13, and a hollow space 17, which has been formed by matching each of the recesses of the surface of the elements 14 and 15.

In this manner, as shown in figure 6, it is possible to create complex pieces with numerous configurations by merely gluing elements mechanically processed beforehand.

Figure 7 shows a perspective internal view of an element 18 according to the in- vention, wherein the ceramic has been injected by strips, forming plates 19 inside of the element. This figure also shows a ceramic layer 20, applied only to one face of the element in order to provide a better viewing of the inside of the element.

Figure 8 shows a perspective internal view of an element 21 according to the in- vention with the ceramic injected at specific points, forming cylinders 22.

In addition to the embodiments presented above, the same inventive concept can be applied to other alternatives or possible utilization of the invention. Thus, it will be understood that the present invention should be construed in a broad manner, its compre- hension being determined by the terms of the accompanying claims.