FR2497725A1 - COATED PANEL FOR PREPARING MOLDS AND CONCRETE FORMWORK, AND METHOD FOR MANUFACTURING THE PANEL - Google Patents

Abstract

COATED PANEL FOR CONFECTION OF CONCRETE MOLDS AND ITS MANUFACTURING PROCESS. IT IS CHARACTERIZED IN THAT IT CONSISTS OF A SUBSTRATE (1) FORMED BY PLYWOOD OR AGGLOMERATOR OF PARTICLES OR FIBERS, ETC .; A LAYER 2 OF A HIGHLY ADHESIVE THERMOPLASTIC COPOLYMER BONDED TO THE UPPER FACE OF THE SUBSTRATE (1); THIS THERMOPLASTIC COPOLYMER BEING AN OLEFINIC COPOLYMER CHOSEN FROM THE GROUP INCLUDING POLYETHYLENE COPOLYMERS DENATURED BY AN ACRYLATE, POLYPROPYLENE COPOLYMERS DENATURED BY AN ACRYLATE AND DENATURATED BY DENATURED BY POLYPROPYLENE AND DENATURED BY ACRYLATE FROM ACRYLATEDRYLETHYLETHYLETHYLETHYLETHYLETHYLETHYLETHYLETHYLETHYLATE AND DENATURED BY ACRYLATE WITH DYERETHYLETHYLETHYLENE AND DENATURATED BY DENATURED BY ACRYLATE AND DENATURED BY ACRYLATE DENETHYLETHYLETHYLATE ETHYLENE. THE INVENTION ALSO DESCRIBES A PROCESS FOR PRODUCING SUCH A COATED PANEL.

Description

The present invention relates generally to a panel

  coating for making molds or concrete forms and more particularly for a coated board used to produce such molds or forms which comprises a substrate of wood or a cellulosic material and a layer of a thermoplastic copolymer adhered thereto. The invention

  also relates to a method for producing such a panel.

  Wood panels or planks have been widely used in public works and construction to make molds and concrete forms. These panels include cellulosic materials, such as plywood and agglomerates of particles and fibers. However,

  these materials tend to adhere to the concrete as it hardens.

  here, because the fresh concrete penetrates and becomes embedded in the surface of the

  trat. As a result, cured concrete fragments attach to the mold panel, unless fragments of it break off and stick to the surface of the concrete at the time of demolding, thus preventing repeated use of the panel or deteriorating the appearance of cast concrete. Some

  thermoplastics, such as polyolefins, especially poly-

  ethylene and polypropylene, have been found to have satifi-

  These materials can be easily removed from molded concrete on the cellulosic substrate, which means that these materials can be easily removed from the molded concrete without flaking off. However, these thermoplastics have the defect of sticking with difficulty, directly on the surface of the substrate, by the sole application of heat and pressure, and even when they adhere to it in the form of a layer, this requires a relatively long time of application of heat and pressure, to which is added that the adhesive force is insufficient for practical uses, the resulting layer easily peeling off the substrate at the time of use. Although these common thermoplastics can be applied to a substrate with a bonding agent, there is no

  no less than a problem in the manufacture of mold panels because the soil

  harmful agent that may be contained in this binding agent will evaporate during the bonding or bonding process, polluting the environment

of the workplace.

  The present invention is based on the discovery that certain copoly-

  thermoplastic matrices such as those of the olefinic group, for example

  acrylate-denatured polyethylene polymer, acrylate-denatured polypropylene copolymer, ethylene vinyl acetate copolymer, ethylene-ethylacrylate copolymer, etc., exhibit a bond strength, that is to say a greater adhesion when they are directly adhered to the surface of a wood substrate or the like by an application

  heat and pressure, while having good separating properties.

  when you want to remove them from the molded concrete surface. These particu

  are extremely useful for forming concrete structures whose

  face is discovered after the demolding and in the case where the molds having

  served for this purpose must be reused a number of times. These copoly-

  Thermoplastic matrices also have good properties of resistance to water and chemical agents, properties that are useful in the case of molds

  concrete to be used repeatedly.

  Accordingly, the main object of the invention is to produce a coated board for concrete molds covered with a thern copolymer. oplastic which is directly and firmly adhered to the surface of this substrate, but which can be easily detached from the surface of the hardened concrete, thus avoiding

  the coating peels off or peels off when the panel is removed after

  thus producing on the concrete a satisfactory finished surface, all

  by allowing many reuses of the mold.

  Another object of the invention is to provide a method for producing a coated panel comprising a layer or a coating consisting of a thermoplastic copolymer which can be uniformly and firmly bonded to

  the surface of the celluiesic substrate without buckling during solidification.

  tion. Such a curl of the thermoplastic layer occurs when the thermoplastic material, after being melted, solidifies relatively quickly on

  the substrate whose surface is exposed to ambient air, as it is generically

  the case in conventional mold board production processes having thermoplastic coatings adhered by the application of the

  heat and pressure. In other words, a relatively slow cooling

  of the molten thermoplastic material causes a relative shrinkage

  important, so that the solidified layer or coating pre-

  There is a tendency for buckling or warping which may weaken the bond between the thermoplastic layer and the substrate. In the process of the present invention, the thermoplastic polymer

  substrate of a protective or release film or an outer layer

  thermoplastic copolymer, which is superimposed directly on the substrate, the thermoplastic copolymer layer being protected by the release liner or by the outer layer which is exposed to ambient air during the entire gluing procedure. Thus, the thermoplastic copolymer cools more slowly and has less tendency to shrink, providing a uniform and solid bond between it and the substrate surface. Other features and advantages of the invention will emerge

  description which will be given below by way of example, which is in no way

  with reference to the accompanying drawings in which: - Figure I is a schematic sectional view of a coated panel having a protective or release film according to a preferred embodiment of the present invention; FIG. 2 is a diagrammatic sectional view of a coated panel comprising a release liner in accordance with another preferred embodiment of the present invention; FIG. 3 is a schematic perspective view of a portion of the coated panel of FIG. 2; Figure 4 is a schematic sectional view of a coated panel without a release liner, in accordance with another preferred embodiment of the invention; FIG. 5 is a schematic view of an installation for practicing the principles of the present invention and which makes it possible to

  depositing a composite material comprising a sheet of a thermo-

  plastic and an outer sheet of a thermoplastic polymer on the substrate - Figure 6 is a schematic sectional view of a coated panel o

  plywood, which has a coating of a thermo-

  plastic, is glued to a number of lower plywoods to form a coated laminate; and - Figures 7 to 9 are schematic views illustrating different examples for covering the upper plywood of a coating comprising

  a sheet of a thermoplastic copolymer.

  Referring to Figure 1, there is shown a plate or a coated panel according to the invention, which comprises a wood substrate or the like.

  surface adheres a layer or coating 2. Panel I is a counter

  plated about 12 mm thick, but it could just as well be another woody material, for example agglomerated chips, fibers, etc. The coating 2 is made of a highly adhesive thermoplastic material, for example an olefinic copolymer. The preferred olefinic copolymers are those obtained by denaturing olefinic resins with an acrylate, by

  polyethylene copolymers denatured with an acrylate,

  polypropylene denatured polypropylene matrices, as well as copolymers

  vinyl acetate and ethylene or ethylacrylate and ethylene. The coating

  2 has been bonded to the surface of the wood substrate I by application of heat and pressure. The coating 2 covers the entire upper face of the substrate 1, its thickness being a function of the needs, this thickness being preferably between about 0.1 and 0.2 mm. This coating may contain antistatic and / or anti-fading agents. In order to produce this coated panel, the thermoplastic copolymer is placed on the upper surface of the substrate I in the form of a sheet or a powder, and then a protective film 3 made of paper impregnated with a silicone resin is applied to the substrate. sheet or the powder layer so that it is interposed between the latter and the substrate 1. This "sandwich" is then heated above the melting point of the copolymer while applying a pressure, in order to melt it , but not the protective film 3. After heating, the whole is allowed to cool to room temperature leaving the protective film 3 in place, so that the copolymer cools slowly by sticking or welding to the surface of the substrate 1. More specifically, the copolymer resolidifies while its outer face is protected by the film 3, which avoids that cooling, it lose too quickly its heat, that is to say, that is done an idle cooling which avoids the curl of the coating 2 bonded to the substrate 1. In fact, such a curl would inevitably have occurred if the copolymer had cooled while its surface is in contact with the air, because under these conditions, internal stresses would have developed in the copolymer because of the difference in the contraction rates between the latter and the substrate. As a result, the coating 2 glues uniformly and firmly to the substrate I and is not likely to peel off when the hardened concrete is demolded. After the coating 2 has solidified, which is normally completed in a few seconds, the protective film 3 can be detached from the adhered coating on the substrate 1. Thus,

  for example, this film can be removed immediately after the

  2, only on the construction site, to prevent the surface from being damaged before.the final use. The protective film

  could be a fabric impregnated with silicone or a film

made of this material.

  Figures 2 and 3 show another preferred embodiment

  of the present invention in which the outer layer of a thermally

  plastic was superimposed on the coating 2 consisting of a thermoplastic compolymer. The thermoplastic material forming the outer layer 4 must have a melting point higher than that of the copolymer constituting the

  coating 2, this material being an olefinic polymer of a monomer corresponding to

  which is the basic component of the thermoplastic copolymer above.

  In other words, polyethylene is used as material for the outer layer 4 when the copolymer used for the coating 2 is an acrylate-denatured polyethylene copolymer, a copolymer of vinyl acetate and ethylene, or a copolymer of ethyl acrylate and ethylene, while polypropylene is used when the copolymer is an acrylate-denatured polypropylene. These olefinic polymers are preferably used in the form of an oriented film. The above thermoplastic copolymers retain excellent properties, such as mechanical strength, chemical resistance, electrical insulation, etc., which are inherent in these olefinic polymers, and these copolymers, by melting, are incorporated into the corresponding olefinic polymers being softened, so that the molten copolymer readily welds to the corresponding polymers when

  they are heated together so as to melt the first and soften the second.

  The outer layer 4 and the coating 2 are applied to the substrate 1 in the form of a sheet approximately 0.1 mm thick while the latter

  is in contact with the upper face of the substrate I and the film is applied

  3 above mentioned on the outer face of the outer layer 4 so as to interpose the latter and the coating 2 between the protective film 3 and the substrate 1. Then, the sandwich thus formed is subjected to the action of the heat and pressure between the platens of a press, in order to melt the cover copolymer, by softening the polymer of the outer layer, and then allow the whole to cool to room temperature so that the surface in contact with the the substrate 1, as well as the outer layer 4, solidify by sticking. Under these conditions, the outer layer 4 cooperates with the protective film 3 to slow the solidification and to ensure a solid attachment of the coating 2 on the

  substrate I and on the outer layer 2, for the reasons indicated above.

  The protective film 3, after the cover copolymer has become

  completely solidified, can be peeled off at any time, when it is necessary

  sary. The cover material can be applied to the substrate I in the form of a sheet or powder and in the first case, the cover sheet is preferably welded to the outer sheet 4 at appropriate points in order to avoid any risk of slipping between these two sheets

  during the application of heat and pressure.

  FIG. 5 schematically represents a preferred installation for cutting and gluing the cover sheet 2 consisting of a thermoplastic copolymer and the outer sheet 4 made of a cheap thermoplastic polymer, on the substrate 1. The sheets 2 and 4 are debited with continued

  rollers 6 and 7 and are placed against the outer face of a roll.

  the upper water 8 o they come into contact with each other, the sheet 2 facing the substrate 1. The upper roller 8 is heated so that the temperature of its surface is greater than the point of fiusicn of ef'uii The sheets 2 and 4, thus in contact with one another, are then continuously applied to the upper surface of the substrate, which is driven on a conveyor 9, and they are pressed against the surface of the conveyor. 1 between the upper roller 8 and a lower reuleau 10 having an elastic outer surface, so that the cover sheet 2 is subjected to the action of heat and pressure -ar the upper roller 8

  and thus sticks to the outer sheet 4 and aus bstrati. The LemFgra-

  The surface area and the speed of rotation of the upper roller 8 must of course be chosen according to the maturity of the sheets 2, 4 used and the state of the surface of the substrate 1. The outer layer 4 also contributes, as it has been indicated above, to slow the solidification of the coating material to produce a strong bond of the coating layer 2 to the substrate 1 and to the outer layer 4. The sheets 2, LA could be applied in a laminated form produced by a suitable preumatic method. In the above method, to prevent the outer layer 4 from adhering to the upper roll 8, the surface of the latter could be treated with a fluorocarbon polymer or else. a non-sticking agent could be sprayed on the surface of the outer layer 4. The layers 2 and 4 which were thus continuously adhered to the substrate 1, are finally cut according to the contours of the substrate 1 a2in to produce a coated panel, as the one shown in FIG. 4, the outer layer 4 of which has undergone a

  finishing treatment giving it a uniform thickness and a smooth surface.

  Referring to Fig. 6, there is shown a plasterboard which consists of an upper plywood 12 having a layer of coatings 2, made of a very adhesive thermoplastic copolymer, and several lower plywoods. The upper 12 and lower 13 plywoods are 0.5 to 3 mm thick and are bonded together by means of a suitable thermosetting resin such as a melamine or diailyl phthalate resin, by a

  conventional method cou-amnet-nt used in the manufacturel contrepIaqués.

  The thermoplastic copolymer can be applied in the form of a powder or a film of about 0.1 μm thickness on the upper plywood 12, and this covering material is fixed by a heat application. and of

  pressure on plywood siphers 12. The coating or covering

  ture 2 could be covered with an outer layer 4 of a thermo-

  plastic, as explained above.

  Fig. 7 shows the structure of the upper coated ply-conifer 12, which has been produced by placing a sheet 14 of a thermoplastic copolymer on the upper plywood 12, dispersing a release agent such as silicone, under the form of a powder or an emulsion, uniformly over the entire upper face of the plywood 12, so as to cover the sheet 14 with a layer 15 of this agent, then applying pressure and heat to the resulting superimposed assembly, between the two plates 16 and 17 of a press, in order to melt the thermoplastic copolymer, so that it sticks to the upper plywood 12, thereby producing the coating layer 2 by resolidifying. The top plate of the press can be easily removed from the coating layer thus formed, thanks to the anti-adhesive agent

above.

  Figures 8 and 9 show other structures of the plywood above

  12 having composite coatings comprising the thermoplastic layer 2 and the corresponding thermoplastic polymeric layer 4, as described above. Each layer is applied to the upper plywood 12,

  in the form of a sheet 18, 19, and then the resulting laminate is subjected to

  both to the action of heat and pressure between the trays 16 and 17, to bond the outer sheet 19 to the upper plywood 12 by

  intermediate of the cover layer 18 which is welded to the counter

  12 and to the sheet 19. In order to be able to easily remove the upper plate 16 from the finished surface of the plywood 12, a

  Silicone 3 release film could be superimposed over the entire

  16, as shown in FIG. 8, or an emulsion 20 of a release agent could be applied over the entire surface of the sheet 19, as shown in FIG. 9. The top panel thus coated prepared is then bonded to a number of lower plywoods 13 using as adhesives the thermosetting materials mentioned above, which have the reference 22 in Figure 6, to form a plywood with a cover layer 2 made of a thermoplastic copolymer. In this method, the coating 2, which has already solidified on the upper plywood 12, is again subjected to the action of heat and pressure, which promotes the uniformity of its surface and the its adherence thereto to the upper substrate or plywood 12. Consequently, even in the case where the coating 2 would not have been sufficiently firmly adhered to the upper plywood 12 during

  of the first operation, that is, if a few points of the

  12 had not been welded to the surface of the plywood 12, this

  production of plywood brings additional heat and

  to the coating layer 2, possibly defective, so as to bond

  this one completely to the upper plywood 12.

  The following examples, which of course have no limiting character,

  will better understand the particularities of the invention.

EXAMPLE 1

  A sheet 0.1 mm thick of a thermoplastic copolymer is placed

  a highly adhesive tick, which is an acrylate-denatured polyethylene having a melting point of about 1250C and which is sold commercially as CMP-HA50 by the Japanese company "Toner Petrochemical Industries Ltd", on

  a plywood 12 mm thick measuring 900 mm by 1800 mm, and superimposed

  lay evenly on the whole surface of this sheet a protective film

  non-stick coating made from commercially available silicone impregnated paper

3

  under the name DN-TP-APZ-S (DE-3) and weighing 130 g / cm. The assembly is then heated to a temperature of 1700C at a pressure of 8 kg / cm 2 between

  platters of a press for 2 minutes. During this operation, an aerator

  may be carried out, if necessary. After cooling for a few seconds at room temperature, the protective film is removed from the

  polymer surface that adheres to the plywood.

EXAMPLE 2

  A low pressure polyethylene sheet having a

  thickness of 0.1 mm and a melting point of 190C and the same

  strongly adhesive plastic (CMP-HA50) than that used in Example 1, on a plywood having the same dimensions as in Example 1, so that the above copolymer sheet is interposed between the sheet of polyethylene and plywood, and a release sheet, as above, is applied to the polyethylene sheet. The laminated assembly thus produced is then heated to a temperature of 1700.degree.

  12 kg / cm for 3 minutes between the same trays as in Example 1.

  A few seconds after the assembly has cooled to room temperature, the protective film is removed from the surface of the polyethylene sheet

  which is glued, via the copolymer, to the plywood.

EXAMPLE 3

  The procedure is as in Example 2, except that a sheet of

  polyethylene having a melting point of 1500C and heating the whole

  applied at a temperature of 1600C.

EXAMPLE 4

  A 0.1 mm thick sheet of a thermoplastic copolymer is placed

  strongly adhesive, which is acrylate-denatured polypropylene, having a melting point of about 1270C and which is commercially sold under the trademark CMP-HA20 by the aforementioned company, on a plywood having the same

  dimensions as in Example 1. The same anti-scratch film is then applied.

  adhesive than in Example 1 over the entire surface of the sheet. Then, the whole is heated to a temperature of 190 ° C. under a pressure of 15 kg / cm 2 for 3 minutes, using the same press as in Example 1. After cooling for a few seconds, the anti-film is removed. -adhesive

  the surface of the sheet stuck to the plywood.

EXAMPLE 5

  A sheet 0.1 mm thick of a thermoplastic copolymer is placed

  strongly adhesive, a copolymer of vinyl acetate and ethylene having a melting point of 950C, on plywood with the same dimensions

  than before, and apply the same protective film or anti-

  adhesive on the entire surface of the sheet. Then, the whole is heated to a temperature of 130 ° C. under a pressure of 10 kg / cm 2 for 2 minutes.

  the same way as in example 4. A few seconds after cooling down

  at room temperature, remove the protective film from the

  surface of the sheet glued to the plywood.

EXAMPLE 6

  The procedure is as in Example 5 but using, for the highly adhesive thermoplastic material, an ethylene ethylacrylate having a point

  melting point of 90 ° C to produce a plywood with an ethyl acetate

ethylene crylate.

EXAMPLE 7

  A sheet of 0.1 mm thick of a very adhesive copolymer, which is an acrylate-denatured polyethylene having a melting point of 90 ° C. and which is sold under the brand name ADMER VE300 by the Japanese company Mitsui Petrochemical Industries Ltd., and a sheet 0.1 mm thick of a polyethylene having a melting point of 180 ° C and placing the assembly formed of these two different sheets on the upper face of plywood 12 mm thick by means of a heated rotary roller, the surface of which is covered with a fluorocarbon polymer and whose temperature is maintained at 2300C. Then, compressing the above assembly against the upper face of the plywood between the heated rotary roller and a roller which is in contact with the underside of the plywood,

  while the latter passes between these rollers at a speed of 20 m / min.

EXAMPLE 8

  The procedure is as in Example 7, except that the thermoplastic copolymer

  strongly used adhesive is a polypropylene denatured with acrylate

  Late having a melting point of 1200C and which is sold commercially as ADMER NE 050 by the aforementioned company, in place of ADMER VE300 sheet, and a polypropylene sheet having a melting point of 200 C in place of the polyethylene sheet: hylene. The surface of the roll was heated

  at 250 ° C. and the plywood leaves this roll at a speed of 30 m / min.

EXAMPLE 9

  The procedure is as in Example 8, but using a polypropylene having a melting point of 140 ° C. and a heated roll whose surface is

maintained at 190 C.

EXAMPLE 10

  A composite sheet produced by a pneumatic method consisting of a 0.1 μm thick sheet of an adhesive thermoplastic copolymer, which is an acrylate-denatured polyethylene having a melting point of 123 ° C., is used. and which is sold commercially as CMP-HA40 by Japanese company Tonen Petrochemical Industries Ltd., and a 0.1 mm thick sheet of polyethylene having a melting point of 175 ° C and compressed on a plywood 12 wm thick as in example 7. The surface of the roll was heated to 230 C and the plywood

  coating was leaving the roll at a speed of 30 m / min.

  EXAMPLE 11 The procedure is as in Examples 7, 8, 9 and 10 but using

  agglomerated panels 10 nm thick.

EXAMPLE 12

  The procedure is as in Examples 7, 8, 9 and 10, but using 10-μm thick fibreboard.

EXAMPLE 13

  The procedure is as in Example 10 with a 12 mm plywood using a heated iron roll having no surface layer of fluorocarbon polymer, but using a 130 g / cm 3 silicone impregnated release paper sold in trade as DN-TP-APZ-S (DE-3), on the composite set above. This non-stick paper is removed from the composite assembly bonded to the plywood a few minutes after

this one left the roll.

EXAMPLE 14

  The same high-strength thermoplastic copolymer sheet as used in Example 1 is placed over the entire upper face of a plywood of 1.6 mm thickness measuring 900 mm by 1800 mm, and a powder of a release agent sold commercially as Lubron L-5 by the Japanese company Daikin Kogyo Co., Ltd., uniformly over the entire surface of the sheet. Then, the plywood is heated with the sheet and the non-stick powder which it carries at a temperature of 160 ° C.

2

  a pressure of 5 kg / cm, between the plates of a press for 30 seconds.

  A few seconds after the assembly has cooled down to room temperature, this plywood is glued with the sheet welded to it and a number of other plywoods having the same dimensions by means of a melamine resin while operating at a temperature of 120 ° C for 50 minutes under a

  pressure of 10 kg / cm, to form a plywood coated.

EXAMPLE 15

  A highly adhesive thermoplastic sheet, similar to that used in Example 1, is superimposed and a sheet 0.1 mm thick

  low pressure polyethylene having a melting point of 1900C on a counter

  plated with a thickness of 1,6 mm measuring 900 mm by 1,800 mm so that the sheet

  copolymer is interposed between the polyethylene sheet and the counter

  plated, and the same release paper as in Example 13 was placed over the entire surface of the ethylene sheet. Then, the assembly thus formed is heated at a temperature of 1700C under a pressure of 10 kg / cm 2 for 40 seconds, between the plates of a press. The same procedure as that described in Example 14 was shown with the plywood thus coated to form

  a corresponding coated laminated plywood.

EXAMPLE 16

  The same laminate product as that described in Example 15 was prepared except that a silicone emulsion sold under the trade name KM 742 by the Japanese company Shin-Etsu Chemical Industry Co., Ltd., was dispersed over the entire area. surface of the polyethylene sheet instead of the release agent powder. This layered product is treated in the same way as

  in Example II to form a coated plywood.

  All the layers of coatings thus formed on the substrates in the preceding examples could not be peeled off from them by hand and were found to have excellent strength properties.

  bonding and uniformity of the surface, compared to

  are used for concrete molds in which the thermo-

  plastic cover is directly bonded to the same substrate by the action of heat and pressure, all these layers nevertheless retaining the same properties of water resistance, hardness, etc., as those of the panels

  conventional compositions comprising thermoplastic polymer coatings. As a result

  As a result, the coated panel of the present invention has remarkable durability

  and can be reused a greater number of times than traditional

tional.

  The highly adhesive thermoplastic copolymer used could

  contain acid anhydride, such as maleic anhydride or anhy-

  druid of phthalic acid. The thickness of the cover layer and the other dimensions may vary within the known usual limits, depending on the application envisaged, the numerical values indicated above having

  an indicative and in no way limitative character.

Claims (10)

  1. Coated panel for making molds or concrete forms, characterized in that it comprises a substrate (1) formed by a plywood   or an agglomerate of particles or fibers, etc .; a layer (2) of a copolymer   strongly adhesive thermoplastic mother bonded to the upper face of the substrate (1); said thermoplastic copolymer being an olefinic copolymer selected from the group consisting of acrylate-denatured polyethylene copolymers, acrylate-denatured polypropylene copolymers, ethylene vinyl acetate copolymers and ethyl acrylate copolymers and ethylene.   2. coated panel according to claim 1, characterized in that it also comprises an outer layer (4) of a thermoplastic material having a melting point higher than that of the highly adhesive thermoplastic copolymer, this outer layer (4) covering any the surface of thermoplastic copolymer.   Coated board according to claim 2, characterized in that   the thermoplastic material is an olefinic polymer produced from the mono-   corresponding mother which is the basic constituent of the thermoplastic copolymer.   Process for producing a coated board, characterized in that it consists in applying a highly adhesive thermoplastic copolymer to the surface of a wood-based substrate, such as plywood, boards   agglomerated particles or fibers, etc .; to cover this thermoplastic copolymer   of a protective or non-stick film so that it is interpolated   between the substrate and the release liner; to apply heat   and a pressure thereon so as to melt the thermoplastic copolymer   tick, without melting the non-stick film; allow the mixture to cool to room temperature with the nonstick film in place to allow the molten copolymer to solidify and stick to the surface   substrate; and detaching the release liner from the copolytic layer   thermoplastic mother formed on the substrate.   5. Method according to claim 1, characterized in that the thermoplastic copolymer is applied in the form of a sheet on the surface of the substrate. 6. Method according to claim 4, characterized in that the thermoplastic copolymer is applied in the form of a powder on the surface of the substrate.   7. Method according to any one of claims 4 to 6, characterized   in that the thermoplastic copolymer is selected from the group consisting of acrylate-denatured polyethylene copolymers, acrylate-saturated polypropylene copolymers, polyvinyl acetate copolymers;   and ethylene and ethylene acrylate and ethylene cepolymers.   8. Process for producing a coated board, characterizes er. what he   consists in applying a sheet of a strong thermoplastic copolymer. : adhere   sif on the surface of a wood-based substrate, such as a plywood panel, an agglomerated panel of particles or fibers. etc .; covering the sheet of the thermoplastic copolymer with an outer layer of a thermoplastic material having a higher melting point than that of the highly adhesive thermoplastic copolymer so as to interpose the sheet of the eopolymer between the outer sheet and the substrate; to apply heat and a   pressure to this set so as to melt the heat-polymer c-polymer   plastic while softening the outer sheet; and to have cool this   together at room temperature to allow the thermolabile copoliine   previously melted tick to solidify and stick to the laws at the surface   of the substrate and to that of the outer sheet.   9. Method according to claim 8, characterized in that the sheet   thermoplastic copolymer and the outer sheet of the thermo-   plastic were welded together at appropriate points in order to be able to be placed together on the substrate.   10. Process according to claim 8 or 9, characterized in that the thermoplastic copolymer is believed to be in the group comprising eopolymers.   of polyethylenes denatured by an acrylate, the polypropylene copolymers dementia   by an acrylate, the zopolyaeres of vinyl acetate and ethylene and lta   copolyners of ethyl acrylate and ethylene; and that the thermoplastic material   tick forming the outer leaf is a final key polynomial produced from   corresponding monomer which is the basic constituent of the thermopias copolymer. tick.