MXPA97000873A - Procedure for manufacturing a r cover with natural or synthetic wood coating, and obteni products - Google Patents

Abstract

Method for the manufacture of a natural or synthetic wood floor covering characterized by a single-stage assembly, a backing face forming the backing sheet, a middle layer composed of a mixture of fine organic particles and a substantially non-combustible adhesive. crisscross that forms the core of the floor covering, a decorative face and optionally a sheet that forms the surface of use, the assembly is compressed at high temperature and under high pressure, causing the adhesive to cross over.

Description

'? 0CEDII1IENT0 PflRfl Lfl MANUFACTURING OF A FLOOR COVER WITH NATURAL OR SYNTHETIC WOOD COATING, AND PRODUCTS OBTAINED FIELD OF THE INVENTION The present invention relates to a process for the manufacture of a floor covering comprising a r and t of natural or synthetic wood. J.U The present invention refers to ambien a ob + floor coverings through the procedure, including either a natural wood cladding or a synthetic cladding.

L5 TECHNOLOGICAL BACKGROUND Recently, numerous floor coverings that mimic parquet or wooden floors have appeared on the market. They turn the shape of a core produced from 0 particle and / or agglomerated pound boards and, on the one hand, on the upper face, the decorative reverse that can consist of either a sheet of wood veneer or a sheet of paper treated with printed paper or a synthetic sheet and, on the other hand, a contingent sheet of paper or of balance on the reverse side. To increase strength, particularly in use, an additional layer is often placed on the decorative coating, either by depositing a polyurethane varnish or optionally by depositing a plastic sheet. from melamí to tran lúci a. The manufacturing technique is carried out as follows: first a mixed body is constructed, intended to produce the support board or core, preferably with the aid of a mixture of particles and / or wood fibers with adhesive. This adhesive may consist, for example, of fiamolic resins or of aminoplastic resins, einamalim, urea ormaldehyde). LO This mixed body is then subjected to suitable temperatures and pressures to obtain a crosslinking of the adhesive. Then, the method consists of covering both sides of the support board with adhesive to make two sheets of coating adhered thereto, on the one hand on the side of the face, and on the other hand, on the reverse side. The mixed body obtained is optionally subjected to another step of finishing or finishing (cutting into strips, milling, etc.), the cover thus obtained preferably being in the form of thin strips which, when assembled, can give Or printing a wooden floor or a parquet floor.

For this purpose, the edges are milled on each side respectively in the form of a groove and a tongue to make it easier to place. However, the covers obtained by this 2b procedure have a number of disadvantages, the main ones of which are insufficient resistance to use, poor resistance to mdentacion and a high sensitivity to moisture. < Improvements to the general procedure have been described especially in documents KZP-f: i-0329154 and EP-fi-0355829, more particularly in order to improve abrasion resistance. The method described in these documents consists essentially in incorporating hard particles in the use layer. 1 document P-2658750 describes a procedure for the manufacture of floor coverings that includes sheets of Lü wood veneer. To increase the resistance to use, hardening of said wood sheets is carried out by means of vacuum impregnation, this being carried out by slow hardening with the aid of printing resins. L5 FR-FI-2658750 discloses a procedure for the manufacture of particle boards that include an annotation consisting essentially of sheets of plastic material or paper sheets that are impregnated with ream and bonded thereon in a intermediate layer consisting of "> 0 a fibrous mat that is easier to press than the particle support pad. This manufacturing process allows to improve the appearance of the surface and reduce the use of material .. The different procedures described are ? b essentially procedures that require the succession of several stages, and this can increase the losses of time and ^ uLere relatively large production spaces. In addition, different techniques have been proposed to produce decorative planks intended for furniture and that can be part of the "formica" plank category. These boards could in no case be used for floor coverings. In particular, its resistance to use is insufficient. In addition, these planks generally have a poor moisture content. The fluid procedures among these techniques can be mentioned. LU US-A-2, 83 L, 794 discloses a process for the production of planks having a recess and whose core is made up of small wood particles. The procedure consists essentially of applying a first coating on which an adhesive is deposited in the form of Lh powder, and then the core of the plank is produced by mixing the wood particles with a binder that is in a constant form and keeping everything.; i? a press working relatively low pressures (of the order of 7 g / cm2) at a temperature of between 35U and 1? 5 ° C. It is appropriate to note that although a migration of the dry adhesive to the core is described in this document, no migration is observed towards the coating of the adhesive that is in the coating / core interface. DE ~ f? - 1904362 describes a procedure for the production of decorative tiles in which said decorative board is produced by pressure and heating e, a single stage. The procedure consists in impregnating the decorative ho with a ream containing elarnine, and then placing the wet mat on this ho and subjecting it to pressures not exceeding hO |.-G / cm2 in the case of temperatures b of the order of 160 ° CH-A-46L792 discloses a process for the manufacture of a mixed-body plank from a core consisting of plant fibers or particles. 'lomer das, which is obtained by application by sprinkling of inelapuna or urea resin in aqueous solution. According to this procedure, one or a number of decorative paper sheets are placed immediately on this core, on both sides, and they are also impregnated with urea or ream. Everything is placed in a press operating at Lb pressures between 12 and 80 kg / cm2 in the case of a maximum temperature of 150 ° C. f-this procedure allows it to be produced • * > > \ panol in a single stage. DE-A-20607 7 describes a process for the manufacture of components from a core consisting essentially of organic materials, inter alia as wet wood flour with a liquid agglutinator such as an arninoplastic or the like, and which is placed a cover that can be paper or any other equivalent, being all gone to compression with heating in a single b stage. The pressures mentioned in this document are in re 20 and JO g / cm2 and sometimes reach 50 kg / e? N2 ,.

UO-A-9013403 discloses a process for the manufacture of components molded from fibers containing ceLulose, such as wood fibers and a binder, which is a condensation, ie ream or soil in liquid form. A viscous binder is then placed on the surface of the core in order to cause the adhesive to bond the papers. The document mentions the following operating conditions of 1 < £ * press. 70 bars at 14 ° 0 for 20 minutes ,. In conclusion, all these documents describe procedures for the production of planks in which the core is obtained from a mixture consisting of vegetable matter with a liquid binder and on which decorative sheets are placed, covered optionally with Lb adhesive. iodine is subjected to pressure, preferably in one stage, with pressures that are always less than 00 kg / cm2 and less than 60 ° C. residual moisture present in the produced boards with the help of the different procedures described, it is probably eliminated during heating, which takes place at a relatively low pressure.

OBJECTIVES OF THE INVENTION The present invention is intended to provide a process for the manufacture of floor coverings with n natural or synthetic wood materials exhibiting improved wear resistance and resistance to mdentation. The present invention is also intended to provide a method for the manufacture of floor coverings that mimic, for example, floorings, which exhibit improved humidity performance. A further objective of the present invention is that of manufacturing that makes it possible to limit the manufacturing stages of floor coverings.MAIN CHARACTERISTIC ELEMENTS OF THE PRESENT INVENTION The present invention relates to a method lh "for the manufacture of floor covering with coating of natural or synthetic wood characterized by - the assembly in a 5a 'the stage of a reverse side acting as a cont'-balance coating, an intermediate layer destined to form the core of the cover and which is elaborated essentially of a mixture of fine organic particles and an essentially uncrosslinked powder adhesive, a decorative and optional coating between a sheet intended to form the use layer, all being held under a press at high temperature and at high pressure in order to provoke the 2b and recult) slow of adhesion. The working temperature at which the o - sane is made is preferably between 120 and 200 ° O, depending on the nature of the adhesive used, while the pressure is between 30 and 150 kg / cm2, and particularly between 85 and 150 kg / cm2. These conditions are subject to change as a function of the cycle times to adapt to the production unit. During the assembly stage, the adhesive moves towards the surface of the intermediate layer or the influence of heat and heat and, on the other hand, makes solidifying the sound and, on the other hand, ba effect of its migration towards the surface, obtain the adhesion of the leaves that form the lining and the counter-frame. According to a first embodiment of the present invention, the intermediate layer destined to form the core consists simply of a dry mixture of fine organic particles and non-entwined powder adhesive, which is packaged lightly so that it can be it is possible to deposit on it successively the decorative lining and optionally the sheet destined to form the use layer. However, it is observed that when the press is closed, the air contained in the mixture of fine organic particles and adhesive escapes, entraining paiticuias or dust, running < ts? the risk of contamination of the decoration. In addition, the application of pressure and the densification caused by this application of pressure produce tensions in the flour and adhesive, which finally is expressed in considerable distortions in the finished product. With the aim of improving the qualities of the finished product and according to another preferred embodiment of the present invention, it is possible to contemplate the intermediate layer made in the form of a "cake" obtained during a preliminary stage to the stage of assemble, moistening the mixture of fine organic particles and powdered adhesive essentially < * crisscrossed at low temperature and under pressure. This does It is possible, while working at a low temperature, to melt the adhesive by avoiding the time it takes to recirculate. The quantities used for this preliminary stage of manufacture of the "cake" is preferably between 50 and L00 ° C, while the pressure is between 30 and 100 kg / e? N2. This procedure also makes it possible, advantageously, to obtain practically complete degassing. This step is avoided as the tension is released during the application of pressure during the assembly stage, which may result in increase to distortions in the product finished. In general, it is of course possible to adapt the composition of the core to the use to which it is made, and in particular as a function of the desired properties (higher or lower density, hardness and water resistance), [n ' > In particular, the fine organic particles consist of wood flour and / or fibers such as cellulose fibers, to which other synthetic particles are added more harshly. The pulverized adhesive used in the process according to the present invention is preferably a b adhesive of plastic or phenolic or ammoplastic or polyurethane. In accordance with the present invention, it is observed that it is necessary to use additional adhesive to join the cross-sections. In accordance with another embodiment of the present invention it is also possible to stratify the core to save on the amounts of adhesive used and the interventions in the process. In general, it has been observed that Lh is advantageously obtained by a decrease in the number of manufacturing steps in relation to a more conventional procedure ft * \ 'to produce sewing covers. The present invention also relates to the products obtained by the manufacturing process described above. The floor covers according to the invention are characterized in that they successively include a counter-stitching forming the reverse side of the cover, a core obtained from A mixture of fine organic particles and powdered adhesive, a coating that forms the decorative layer and optionally an additional layer that fills the use layer. The coating can consist of either a sheet of wood or a paper treated with printed labeling. In the particular case of a sheet of wood veneer it was observed that the adhesive originating from the core partially degrades the actual wood veneer. The combination of the two phenomena of impregnation and densification by compression advantageously makes it possible to increase the properties <; < the sheet metal hoop and more particularly harden- and reinforce the coating consisting of the veneer, and this allows it to be even less sensitive to moisture.

BRIEF DESCRIPTION OF THE FIGURES Figure L depicts a photograph taken (with an LCO electron microscope) of a sectional view of the decorative fiber-coating interface in the case of a pLSo cover obtained by the method according to the invention in the case of a coating Mien or made of wood Figures 2, 3 and 4 are photographs taken also with the electronic microscope, showing the change in the wood cladding as a function of the treatment.

DESCRIPTION OF EXAMPLES OF THE MODALITY OF THE PRESENT INVENTION Example 1: Synthetic coating 5 A 90/10 homogeneous mixture of wood flour and substantially uncrossed phenolic adhesive powder (for example Peracit H23B14) is prepared in a barrel mixer. Prior to this step it is desirable to carry out an additional drying or drying of the powder adhesive. [The wood / adhesive bead mixture is then uniformly distributed on a flat mold consisting of a metal ruaca and a re-rotable frame. The amount of mixture used is calculated as a function of the thickness and the density of the product to be processed, and the mixture is introduced into a press and positioned under the punch. for 2 minutes under a pressure of 00 kg / crn2 (for example) The mold is taken out of the press After removing the mold, a plank of drivable wood particles called a "cake" is obtained. They form the product are stacked on a sheet of metal conveyor: The counter balance of paper b The plank or cake preaglomerada Ll decorative coating made of treated paper c < -_? me 1 am ina inp re so. of use made of paper treated with impregnated rnelarni at ransparent.The mixed body is covered with a ho whose face is in contact with the use layer that is structured with an imitation of wood grain.It is all introduced under a press and agglomerates in block s at 160 ° C for 8 minutes under a pressure of 125 kg / crn2 jf *? r example). 10 When removed from the press, the mixed body rapidly cools between 2 hot plates. The metal sheets are removed and reintroduced into the circuit. Fl plank or terudo is cut into strips that are milled into tab and slot to facilitate placement. Ib Example 2: Wood veneer '* "The particle board was prepared as in the example 1, but using a mixture 80/20 wood flour - adhesive in p? Lvo. 0 On a sheet of metal transporter-a are placed s u c a i n a n t < - > s The oddly shaped wooden counter (sheet metal). Fl able or cake p rea g.l agglomerated orne rada. L: l decorative cover (sheet metal) .. b The use layer made of paper treated with niel ami a re nothing.

The structured surface plate (grain on the use layer). Everything is transported under a press and agglomerated at 160 ° C for 8 minutes ba or a pressure of 125 kg / cm2. When b is taken out of the press, everything will go quickly between 2 plates. Both sheets of metal are removed and returned to the circuit. The edges of the panel obtained are milled into a tongue and groove shape for the purpose of facilitating 'the c *' '- > eac ion. Figure L shows more particularly a sectional view taken in the electron microscope of the decorative core interface in the case where the reverse consists of a sheet of wood veneer. In order to deploy the impregnation of the Ib sheet of wood veneer with the adhesive it was necessary to prepare a metal stearate, preferably dopa stearate, with this adhesive, with the result that the presence of zinc is observed, preferably in the more porous regions. Immediately, in Figure 1 there is a high concentration of z c between the melamine surface and the sheet metal sheet. From this it can be deduced that the more porous regions of the wood veneer are filled with adhesive, and this allows to improve the properties of said coating. ? b Figures 2, 3 and 4 show the change in the sheet as a treatment function where: Figure 2 shows two views (100 and 900 times respectively) of an untreated sheet. Fig. 3 shows two views (100 and 200 times respectively) of a treated sheet, b "Fig. 4 shows two views (200 and 1000 times respectively) of a channel filled with polymers Also, both in the case of the board (cake) ) As in the case of the synthetic coating and the lining, the improved properties of the water resistance were demonstrated in terms of inflation (Table 1) and in terms of absorption (Table 2), as well as the improved properties in the case of hardness (table 3). In tables 1 and 2 it is seen that the resistance to water in terms of hmchamiento (in percentage) and in terms of l-i absorption (in percentage) increases as a function of the density and the proportion of adhesive used (in "" 'rcent e) "More particularly, in the case of the current board, this increase is by a factor of 30 and by a factor of 50 respectively, for swelling and for absorption in the case of an immersion ion for 24 hours. Similarly, an improvement in the properties of dur-eza (NPa) as a function of the density and the proportion of adhesive used (in percent) is shown in Table 3., > TABLE 1 Resistance to water-Swelling Í3n%) Density j Proportion of adhesive (%) c l culated 10 15 20? R T blón 0 0 Synthetic coating S 0 Wood plank not enamelled b 0 n.rn .: not measurable; destroyed sample TABLE 2 Water resistance-Absorption (in Z) Density Adhesive rate (%) c Filled 5 I 10 1 15 1 20 1 25"ablon Synthetic coating Wood plank non-role Side n. . -. I do not odiLue; destroyed sample TABLE 3 Absorption - Durer (MPa) Density Proportion of adhesive (%) caL culated 10 15 20 25 1 abion Synthetic coating Wooden plank not rolled n.rn,.: not measurable; dostuida

Claims (7)

NOVELTY OF THE INVENTION CLAIMS

1. - Procedure for the manufacture of covers of 5 floor with natural or synthetic wood cladding, characterized in that a reverse side is assembled in a single stage that acts as a contour of a balance, an intermediate layer destined to form the core of the roof and which is essentially made of a mixture of particles The organic elements and a powder adhesive essentially not in recharge, a decorative coating and optionally a sheet intended to form the use layer, all maintaining a high temperature and high pressure press in order to provoke the in recrossing the adhesive. 15 2,. - A method for the manufacture of floor coverings according to claim 1, characterized in that the assembly stage under a press at high temperature and at high pressure is carried out with a tur-a time of between 120 and 200 °. C and a pressure of between 30 and 150 Lg / c? N2, and 20 preferably a pressure between 85 and 150 | g / c? R?

2.

3. Process for the manufacture of floor coverings according to claim 1 or 2 further characterized in that the intermediate layer is intended to form the core consisting simply of a mixture of organic particles and adhesive. In non-crisscrossed powder, this mixture is lightly packed by means of a roller so that it can be possible to deposit successively on the decorative liner and optionally the sheet intended to form the use layer.

4. Process for the manufacture of 5-floor covers according to claim 1 or 2 further characterized in that the intermediate layer consists of a cake obtained before the assembly stage by molding the mixture of organic particles and powder adhesive essentially The process for the manufacture of floor coverings according to claim 4, further characterized because work is done for the manufacturing stage of preparation of the cake at a temperature. between 50 and 100 ° C and a pressure of in re 30 and 100 kg / ern2 .. 15 6.- Procedure for the manufacture of floor coverings of < Onforrnity with any of the referential claims, also characterized by the fact that the fine organic particles consist of flour and / or wood fibers such as cellulose fibers, to which they are added optionally. 20 other harder synthetic particles. 7.- Procedure for the manufacture of floor coverings in accordance with any of the preceding claims, characterized in that the adhesive used in poly is an adhesive of the phenolic plastic type or 2b to inoplast or to polyurethane. - Floor cutout with synthetic coating, obtained by means of the procedure described according to any of the preceding claims, characterized in that it includes successively, a contingent tire designed to form the reverse side, a core essentially made of b a mixture of organic particles, preferably wood flour and solvent-free crosslinked adhesive, a paper treated with a printed mole, and optionally a surface use layer. 9.- Floor cover with wooden reinforcement Natural, obtained by the method described in accordance with any of claims 1 to 6, further characterized in that it includes successively a rare element intended to form the reverse side, a core essentially made of a mixture of particles Ib organic, preferably wood flour and solvent-free crosslinked adhesive, a sheet of wood veneer and CLonalutente a layer of surface use. LO.- Floor covering with natural wood covering according to claim 9, characterized in that this adhesive is also crosslinked in the porosities of the natural wood covering.