FR2578188A1 - Method for manufacturing agglomerated covering panels - Google Patents

Abstract

THE PRESENT INVENTION RELATES TO A PROCESS FOR THE MANUFACTURING OF COATING PLATES BASED ON HARD MATERIALS, PREVIOUSLY REDUCED TO GRAIN AND POWDER, AGGLOMERATED USING SYNTHETIC RESINS, SAID COATING PLATES BEING ESPECIALLY INTENDED FOR COATING. ACCORDING TO THE INVENTION, ON A CONTINUOUS MOVING BELT 1, IN PARTICULAR PREVIOUSLY COATED WITH A RELEASE AGENT, SUCCESSIVELY TWO LAYERS OF BINDER 5 AND 8 BASED ON SYNTHETIC RESINS OF DIFFERENT COMPOSITIONS, THE OUTER SIDE OF THE SIDING PLATE. OF COATING BEING THE FACE 27 IN CONTACT WITH THE BELT 1. THEN IS DISTRIBUTED SELECTIVELY IN THE BAND 22 THUS FORMED BY THE TWO SUPERIMPOSED LAYERS, TWO TYPES OF PELLETS 10 AND 15 SUCH AS THE FIRST 10 DESCEND IN THE FIRST LAYER OF BINDER 5 AND THAT THE SECOND 15 OCCUPY THE SECOND LAYER OF BINDER 8.

Description

The present invention relates to a method of manufacturing plates

  of agglomerated coating. More particularly, the invention relates to a method of manufacturing coating plates based on hard materials, previously reduced in grains and powder, agglomerated with synthetic resins. It will find particular application in the field of construction and building to obtain cladding plates, particularly for the

exterior wall cladding.

  It is known a number of methods for making plates made of synthetic resins and stones, marble, granite or any other

  hard material previously reduced to grains or powder.

  In some of these processes, coating plates of varying size, width and thickness are obtained by molding. A dyed dough is prepared by incorporating fillers and granules into resin and then the dough is molded at high pressure, the resulting plates then undergoing different treatments, such as

  drying, polishing and grinding.

  By this type of process, one obtains wear-resistant coating plates, of decorative appearance, which can imitate the natural stone, the marble, but it does not allow to produce industrially-such plates which are thin,

rigid and flat.

  Furthermore, there is also known a method of manufacturing coating plates based on hard materials previously reduced in grains or powder, agglomerated with synthetic resins, which can produce industrially and continuously a product that has good flatness and good rigidity. In addition, this process solves the problems of material withdrawal occurring

  especially during the polymerization of the resin.

  In this known method of continuous manufacture of coating plates, the practice is as follows: - a thin layer of synthetic resin-based binder is deposited on a continuously moving conveyor belt, previously coated with a release agent; of hard powdery materials, of very regular thickness, - is deposited on this binder layer granules of - materials selected and mixed in specific proportions, - these granules are penetrated into the binder layer, - this layer is finally covered thus obtained from a layer of sole granules which adhere to the surface of the ribbon, - the wall thus formed is subjected to additional operations such as in particular drying in a furnace of

  polymerization, cutting into plates, polishing of the plates.

  The product thus obtained by this process has excellent qualities of strength and flatness which are particularly intended for use in soil materials. On the other hand, because of the use of granules of noble materials, these granules having to constitute all the thickness of the layer of the coating plate, its cost is relatively important and therefore, excludes its use to the coating of large areas such as

exterior wall coverings.

  In order to reduce the cost price of the cladding boards and to be able to use them for exterior wall claddings, it is necessary to use less noble materials than marble or granite but, as a result, the aesthetic quality of the finished product is diminished. To achieve a compromise, it is then possible to imagine using cladding plates consisting of two layers, the first intended to be the outer facing face comprising noble materials, such as in particular marble, the second being made of materials more poor, such as for example common black marbles or granules from crushed local stones. But then the application of the method described above can no longer be implemented because it is necessary to selectively distribute in the band continuously the types of

different materials.

  Knowing the state of the art, it could have been obvious to those skilled in the art to carry out the following process: a first layer of binder is produced in which a first type of hard material is dispensed and then a second layer of binder is produced; in which a second type of hard material is dispensed, the two

  layers and polymerization is carried out.

  The implementation of this process seems impossible because there will necessarily be a lack of connection between the two layers of resin, which will make plates

  poor quality coating.

  Another reasoning could have been held by a person skilled in the art by making the coating plates in the following manner: a thick layer of binder is deposited on a continuous carpet, and then a first type of hard material is first dispensed. forming the siding fade and then distributing a second type of hard material to complete the layer, the polymerization then harden the product manufactured. Considering this type of process, one would obtain agglomerated coating plates having a selective distribution of materials in the band but cons no saving compared to the process using a single type of hard material because the fact of using a large binder layer makes this process very expensive, despite the economy

performed on hard materials.

  A last type of manufacture, by which, in a thick layer of binder, a mixture of granules of different qualities would be dispensed, is not conceivable either because one could not selectively orient the

  different types of hard materials in the layer.

  The object of the present invention is therefore to propose a solution to this problem, that is to say the production of coating plates based on hard materials, previously reduced to grains or powder, agglomerated with the aid of synthetic resins, consisting of two layers of

  overlapping materials intimately related to each other.

  Another object of the present invention is to provide a method of manufacturing coating plates

  carried out industrially continuously.

  Another object of the present invention is to provide a method of manufacturing coating plates for obtaining a thin product, having a good finish, good flatness and good mechanical strength and whose cost is substantially lowered compared to known manufacturing processes. One of the aims of the present invention is also to produce coating plates whose external appearance is very decorative, being able to

  to imitate in particular marble or other noble materials.

  Other objects and advantages of the present invention

  will appear in the following description, which will

  is given as an indication only and is not intended to limit it. According to the present invention, the method of manufacturing coating plates based on hard materials, previously reduced in grains and powder, agglomerated with the aid of synthetic resins, said coating plates being in particular intended for external wall covering, is characterized in that: a) a continuously moving mat, in particular previously coated with a demoulding agent, is deposited on: - a first layer of binder based on synthetic resin whose face in contact with the carpet is intended to be the outer facing surface of said coating plate, - a second layer of binder based on synthetic resin of different composition from the first, the two layers being superimposed and having an interface, b) selectively distributing in the continuous strip, formed by the two layers of binders: - a first type of granules in the first layer of binder by accelerating the descent from the material through the second layer of binder to the first layer to the facing side; - a second type of granules in the second layer of binder avoiding the descent of the material in the first layer;

binder layer.

  The invention will be better understood on reading the

  following description with accompanying drawings from

  which: - Figure 1 schematically illustrates an overview of the apparatus for implementing the present invention; - Figure 2 shows a sectional view of the plate;

  coating made according to the present invention.

  In the installation illustrated in FIG. 1, allowing the implementation of the method of the present invention, use is made of an endless belts (1) made of steel, at variable speed and of sufficient length for all subsequent operations can be performed in the travel time of a carpet length. In some cases of manufacture, the carpet (1) can be pre-coated

  a release agent at the station (2).

  Then, above the belt (1) are arranged successively different product supply stations and work ncebsires the manufacture of the coating plates. Firstly, a first binder distributor (3) containing, in particular, the so-called noble synthetic resin (4) so as to constitute the first binder layer (5) so-called

"noble layer".

  Then, a second binder distributor (6) containing in particular another synthetic resin (7) called poor, for producing the second layer of binder (8)

called "poor layer".

--7 2578188

  Then there is a first metering hopper-distributor (9) containing a first type of hard material (10) in particular consisting of so-called "noble" raised granules. Under the hopper (10) are arranged a distributor (11) consisting essentially of a bundle of metal blades with decreasing section and two superimposed sieves (12) and (13), the latter for distributing and sprinkling the

granules in a homogeneous way.

  Then there is disposed a second metering hopper (14) which contains a second type of hard material (15) - in particular consisting of washed granules called "poor". This hopper (14) is constituted in a manner similar to the hopper (9), it has a distributor (16)

as well as two sieves (17) and (18).

  After the hopper (9), the carpet (1) is equipped with a

  section subjected to vibrations of a vibrating table (19).

  Then there is a dispensing hopper (20) containing sole granules (21) for depositing on the ribbon (22) in motion, constituted by the two layers

  (5) and (8) superimposed, a grain mat (23).

  Then there is a vibro-compression device (24) for adhering to the

  surface (22) the outsoles (21).

  The moving ribbon is then directed to an oven

polymerization (25).

  Finally, a suction system (26) retrieves all the surplus sole granules, that is to say those which

could not adhere to the ribbon.

  The ribbon is then directed to other workstations not shown in FIG. 1, in which the finishing steps are carried out, that is to say cutting, grinding.

and polishing.

  This installation, as just described, allows in particular to implement the coating plate manufacturing process of the present invention. According to the present invention, the method of manufacturing coating plates based on hard materials, previously reduced in grains and powder, agglomerated with synthetic resins, said coating plates being in particular intended for external wall covering,

  comprises the successive steps described below.

  First of all, a first layer of binder (5) based on synthetic resins (4) is deposited on the mat (1) in continuous motion, in particular previously coated with a release agent at the station (2). The face (27) of this layer (5) in contact with the carpet (1) is intended to be the face

  outer facing of said cladding plate.

  This first layer of binder (5) called "noble layer" is deposited on the carpet by means of the first binder distributor (3) which allows through shaped rollers

  of gears, to obtain a layer of regular thickness.

  The synthetic resin (4) used is in particular constituted by isophthalic type pasty polyester resin. This resin is prepared in a station not shown in FIG. 1, in which the resin is mixed, fillers of hard powdery materials, catalysts and

possibly dyes.

  Then, above this first "noble layer" (5), a second layer of binder (8) based on synthetic resins (7) of different composition is deposited.

9 2518188

  first layer, the two layers (5) and (8) then presenting a

interface (28) common.

  This second binder layer (8) called "lean layer" is in particular constituted by a synthetic resin (7) of orthophthalic type polyester. It is prepared in a station not shown in Figure 1 in which the resin is mixed, pulverulent fillers, catalysts and in particular

dyes.

  This poor binder layer (8) is deposited on top of the noble binder layer (5) by means of the second binder distributor (6). This second splitter is of the same constitution as the first splitter (3) which allows

  in particular to deposit a layer of regular thickness.

  According to a preferred embodiment of the present invention, it should be noted that the two superimposed layers (5) and (8), based on synthetic resins respectively (4) and (7) are pasty, of different viscosity but immiscible. Moreover, they have close and compatible chemical compositions to avoid withdrawals and to obtain

  an inter-reaction between them during the polymerization.

  Then, the strip (22) formed by the two layers of binder (5) and (8) being constituted, selectively distributing in the continuously moving strip the materials

  in particular in the form of washed granules.

  FIG. 2, showing the band (22) whose layers have been enlarged for comprehension, shows the

  selective distribution of materials.

  Firstly, a first type of "noble" granules (10) is deposited by the first metering hopper

0 0

  (9). These granules (10) will gravity pass through said second "poor" binder layer (8) and will reach said first "noble" binder layer (5) as the web travels through the carpet. The descent of the materials (10)? through the layers (8) and (5) to the facing face (27) can be accelerated by using in particular the vibrating table (19) placed on the

scrolling path of the tape.

  Then, it is always deposited above the strip (22) running, which then already comprises the granules (10) of the first type of material "noble", a second type of

pellets (15) called "poor".

  These granules (15) are intended to penetrate into said layer of binder (8) called "poor". They will descend into this layer by gravity and also, in particular, by the action

of the vibrating table (19).

  According to the present invention, the granules (15) will be distributed only in the binder layer (8) without

  reaching said first layer (5).

  To avoid the descent of the granules (15) in the binder layer (5) is played on various parameters, such as in particular the speed of travel of the carpet, the vibration, the particle size, the viscosity of the layers, the relative disposition of the various positions working along the carpet. Similarly, to distribute the first granules (10) selectively in the layer of "noble" binders (5), it also acts on

these different parameters.

  It should be noted that, in order to promote the penetration of the various granules into the layers of binders, the granules are previously coated with a monomer of the following type:

styrene or acrylic.

  The band (22) thus formed is thus directed to the next station (20) by which is distributed above the band a mattress (23) of sole granules (21). The vibro-compression device (24) makes it possible to adhere on the surface of the strip (22) said sole granules (21). During this operation, the deposition of the granules is saturated so as to have a layer of sufficient thickness constituting an insulating blanket to prevent heat shock due to heating and cooling during the polymerization. Thanks to this mattress

  insulation, the withdrawal problems are considerably reduced.

  The belt (1) continues its advance and directs the strip (22) thus coated in the oven (25) and at the outlet of the oven to a vacuum cleaner (26) which recovers all the granules of

  excess sole that did not adhere to the band.

  It should be noted that the polymerization of the resins is carried out cold by addition of catalysts and accelerators, and is completed by a heating

  allowing to have a total polymerization.

  At the end of this manufacturing cycle, the tape is directed to traditional workstations to

  forms the coating plates and polishes them.

  This method makes it possible to obtain coating plates, in particular intended for external wall covering, which is thin, rigid, flat and of a very substantially reduced cost price. By implementing this method, it is possible to realize

2578 1 88

  plates with different types of characteristics and

  especially the product whose example follows.

  A "noble binder layer" (5) is deposited with a base of isophthalic polyester resin of a very small thickness of the order of a few tenths of a millimeter to one millimeter. very thin, the release agent can be included in the layer and not deposited beforehand.In addition, to deposit this layer, one can use the binder distributor (3) but alternatively, one can apply this layer by means of

sprayers.

  Above this first layer of binder (5) is deposited the binder layer (8) "poor" based orthophthalic type polyester resins of greater thickness which may be of the order of one millimeter to twenty millimeters. These two types of different resins are prepared beforehand by mixing hard powdery fillers, catalysts, accelerators and

possibly dyes.

  The noble resin used is particularly resistant to aging but has a relatively high cost price, while the second resin has lower qualities but has the advantage of lowering the

  total cost of the resin layer.

  The belt (1) which moves at a linear speed of the order of 0.5 to 2 meters per minute, then directs the strip (22) formed of the two superposed layers (5) and (8) to the

  metering hoppers (9) and (14).

  The first hopper (9) distributes a first type of granules (10) "noble" which can be constituted in particular by white marbles or cduleur renamed and very selected, whose origins are distant and the cost of which is quite important. By cons, the second hopper (14) distributes a second type of granules "poor" - (15), including consisting of common black marbles or crushed stones

local, whose price is cheap.

  In order for the coating plates obtained to be plates of homogeneous materials and not bi-layers and to avoid the different problems of shrinkage of the two layers during the polymerization, it is necessary that the particle size of the materials (10) and (15) be similar. Thus, the layers will have similar withdrawals, but it should be noted that the more "noble" binder layer (5) is thin,

  at least withdrawal issues will be important.

  It is conceivable to produce a mixture of two-thirds of large granules, that is to say with a particle size of between five and eight millimeters, and one-third of fine granules, that is to say with a particle size of between two and five millimeters, to constitute on the one hand the "noble" mixture (10)

  and on the other hand the "poor" mixture (15).

  Depending on the thickness of the "noble" binder layer (5), the particle size of the mixture of noble materials (10) can be reduced. In this case, to prevent the deposited materials from flowing outside the layer, that is to say the side of the carpet, because the decrease in particle size facilitates the descent of the grains, it will increase the viscosity of the layer of

"noble" binder (5).

  These two types of material are therefore distributed selectively in the strip by acting on the various parameters, such as in particular the running speed of the belt (1), the viscosity of the layers of binders (5) and / or (8), the vibration carpet and the relative arrangement between the two

  distribution hoppers (9) and (14).

  In particular, the vibration of the carpet after the sprinkling of the grains makes it possible in particular to increase the descent

  by gravity of the granules and "debull" the resin.

  The relative distance between the two hoppers (9) and (14) depends in particular on the weights of the "poor" granules (15) which make it possible to accelerate the descent of the "noble" granules (10) into the "poor" layer (8) . On the other hand, the distance of the hopper (14) from the next work station is such that the "poor" materials (15) can not penetrate the layer (5) beyond the interface (28). ). Indeed, it is necessary to avoid in all the cases that the two types of materials are

  mix in the "noble" binder layer (5).

  The belt continues its movement and is directed to the following positions, in particular for the deposition of the insulation blanket, the heating in the polymerization oven,

  the aspiration of the excess granules.

  It should be noted that the realization of the insulation blanket (23) can be carried out by means of granules of expanded material such as expanded clay or expanded shale, as well as elastic materials, which also makes it possible to improve the acoustic characteristics and

  thermal coating plate.

  On the other hand, it could be envisaged to remove this deposit of insole granules, in this case the insulating blanket would consist of a superabundant and excess deposit of the "poor" granules (15) used for the layer (8). In this case, it will adjust the viscosity of this layer so as to retain a certain surface thickness of these granules. The example which has just been described makes it possible to produce coating plates with good mechanical qualities and advantageous cost, especially intended to be used outdoors in techniques.

  say "wall insulation from the outside".

  It should be noted that, according to the present invention, to obtain cladding plates whose outer facing face has a decorative appearance imitating marble, that is to say including irregular colored veins on the surface, we could interpose in the process which has just been described an additional step consisting in the realization of these veinages in the layer of binders

"noble" (5).

  For this, it would suffice to add at the beginning of the production line, instead of the first binder distributor (3) a different resin distribution station, using a known technique by which these veinings are carried out. This post of vining includes an inclined spreading plan for distributing a resin layer from a slot hopper making the entire width of the sheet of the resin, said inclined plane leading to an inclined tongue or a rectilinear head horizontal approaching the horizontal strip of the carpet for transferring the resin layers of the inclined plane to the carpet. During the lowering of the resin layer on the inclined plane, a liquid resin colored differently from the existing layer on the inclined plane is injected onto the face which will ultimately be the external face of the facing, by means of a movable fitting which makes random drawings representing

the desired veining.

  Naturally, other implementations of the present invention, within the reach of those skilled in the art, could

  to be adopted without departing from it.

Claims (15)

  1. A method for producing coating plates based on hard materials, previously reduced in grains and powder, agglomerated with synthetic resins, said coating plates being in particular intended for external wall covering, characterized by the a) is deposited on a carpet (1) in continuous movement, in particular previously coated with a release agent (2): - a first layer of binder (5) based on synthetic resin (4) whose face (5) 27) in contact with the carpet (1) is intended to be the outer face of facing of said covering plate, - a second layer of binder (8) based on synthetic resin (7) of a composition different from the first, the two layers (5) and (8) being superimposed and having an interface (28), b) selectively distributes in the band (22) continuously formed. by the two binder layers (5) and (8): - a first type of granules (10) in the first layer of binder (5) by accelerating the descent of the material through the second layer of binder (8) to the first layer (5) up to the facing face (27), - a second type of granules (15) in the second layer of binder (8) avoiding the descent of the material (15)   in the first layer of binder (5).   2. A method of manufacturing coating plates, according to claim 1, characterized in that: a) is deposited on a carpet (1) in continuous motion, in particular pre-coated with a release agent (2). ), a first layer of binder (5), called "noble layer", based on synthetic resin (4) of regular thickness, loaded with material t. hard powder, via a first binder distributor (3), b) is deposited on this noble layer of binder (5), a second layer of binder (8), called "poor layer" based of synthetic resin (7), of regular thickness, filled with hard pulverulent material via a second binder distributor (6), the two superposed layers (5) and (8) being based on synthetic resin ( 4) and (7) pasty, immiscible and of different viscosity, c) is deposited continuously on the layers (5) and (8) thus superimposed materials in the form of washed granules: - a first metering hopper-distributor (9 ) distributes a first type of "noble" granules (10) which will pass through said second "poor" binder layer (8) and reach said first "noble" binder layer (5) by gravity, - a second metering hopper-distributor (14), placed downstream of the first hopper (9) with respect to the direction of movement of the belt (1) in continuous movement distributes a second type of "poor" granules (15) which will penetrate into said second layer this "poor" binder (8) without reaching   said first "noble" binder layer (5).   3. A method of manufacturing coating plates according to claim 1, characterized in that to penetrate the two types of granules (10) and (15) in the superimposed binder layers (5) and (8). ) the running speed of the moving belt (1), the viscosity of the binder layers (5) and / or (8), the particle size distribution of the types granules (10) and / or (15). 19788188   4. A method of fabricating facing plates according to claim 2, characterized in that the section of the belt (1) is subjected to the hoppers (9) and (14) distributing the granules (10). ) and (15), to a vibration to promote the penetration of said granules into the layers binder (5) and (8).   5. A method of manufacturing-coating plates, according to claim 1, characterized in that the first layer of binder (5) has a very small thickness, of the order of a few tenths of a millimeter to a millimeter relative to the thickness of the second layer of binder (8) which is of the order of one millimeter to twenty millimeters. 6. A method of manufacturing coating plates, according to claim 1, characterized in that the synthetic resins (4) and (7) constituting the layers of binder (5) and (8) superimposed are chemical compositions close and compatible to avoid withdrawals and get a   interaction during polymerization.   7. Process for the production of coating plates, according to claim 6, characterized in that the binder layers (5) and (8) are constituted by polyester resins (4) and (7), that of the first layer (5) being of the isophthalic type, that of the second layer being orthophthalinic type.   8. A process for producing coating plates, according to claim 6, wherein the polymerization of the resins is carried out cold by the addition of catalyst and accelerator products, supplemented by a heating device which makes it possible to have a tetra-polymerization. 9. A process for the manufacture of cladding boards according to claim 2, characterized in that the first type of "noble" narn (10) is in the form of a two-thirds mixture of large granules, that is to say five to eight millimeters, and a third of fine granules,   that is, two to five millimeters.   10. A method of manufacturing coating plates according to claim 2, characterized in that the second type of granules "poor" (15) is in the form of a mixture of two thirds of large granules, that is to say, five to eight millimeters, and a third of fine granules, that is to say from two to five millimeters. 11. A method of manufacturing coating plates, according to claim 2, characterized in that the first type of "noble" granules (10) is selected from white marbles or colors very selected and renowned, the second type of granules "poor" (15) is selected from common marbles or among local stones crushed.   12. Process for the production of coating plates according to claim 2, wherein the different granules are coated with a styrene-type monomer or acrylic or other monomer to facilitate their formation.   penetration into the binder layers.   13. A method of manufacturing coating plates according to claim 1, wherein the release agent (2) is included in first layer of binder (5).   14. A process for the production of coating plates according to claim 1, which is achieved by the fact that a colored and irregular veining is carried out on the surface.   outer face (27) of the covering plates.   15. A method of manufacturing coating plates, according to claim 1, characterized in that said strip (22) including both types of granules (10) and (15) is coated with a layer of sole granules (21) which adhere to the surface of the strip, of great thickness to form an insulation blanket (23) to prevent thermal shock due to heating and   cooling during the polymerization.