Cladding blade with a hydrophobic coating, manufacturing process for a coating compound and cladding blade coating installation.

Abstract

TITLE: Cladding blade with a hydrophobic coating, method for manufacturing a coating compound and a cladding blade coating installation. Cladding blade having pairs of long sides and short sides with assembly profiles, LG, RG, joined at the top by bearing surfaces (11, 21) in the joining plane (PJ) of the blades above the assembly profiles themselves. The bearing surfaces (11, 21) have a coating of natural, water-immiscible, oily, and opaque compounds; this coating combination is applied in a molten state with a penetration and dissolving agent, texturizer and drying agent, a tackifier, a hot melting temperature and viscosity control agent, and a cold texturizer and antioxidant. Figure 1

Description

Title of the invention: Coating blade with hydrophobic coating, method for manufacturing a coating compound and a coating installation for coating blades. FIELD OF INVENTION

[0001] The present invention relates to a cladding panel whose sides have assembly profiles provided with a hydrophobic coating, as well as a method for manufacturing such a coating compound and a panel coating installation. PRIOR TECHNOLOGY

[0002] It is known to improve the sealing of MDF or HDF plank floor coverings to prevent moisture that could enter the planks through their assembly profiles.

[0003] To achieve this, wax is incorporated into the mass of the panel cut into strips. However, the percentage of wax is limited because it reduces the mechanical properties of the panel or the strips cut from it. It is therefore necessary to apply a hydrophobic product to the strip assembly profiles. The product used is an impregnating agent applied to the entire profile and penetrating to a certain depth into the material of the strip.

[0004] It is also known to supplement this treatment with a sealing agent containing sodium polycarbonate, which is a so-called superabsorbent material for water. However, the swelling of the profile resulting from moisture absorption is incompatible with the precision machining of the assembly profiles of the cladding blades.

[0005] In summary, current solutions for reducing or avoiding the penetration of moisture and water into the assembly profiles of floor covering boards do not provide the expected solutions because either by swelling of the assembled profiles or by the over-thickness of the profiles to be assembled, we arrive at results contrary to those sought.

[0006] PURPOSE OF THE INVENTION

[0007] The present invention aims to develop a cladding panel made of MDF and HDF with profiled sides for edge-to-edge assembly by the shape of the panels, and without a surface coating on the profiles that could alter the machined profile, particularly through swelling, but rather with a coating that guarantees the impermeability of the profile. The coating formulation must be applicable to the panel profiles on the profile machining line.

[0008] DESCRIPTION AND ADVANTAGES OF THE INVENTION

[0009] To this end, the invention relates to a hydrophobic coating formulation for an MDF and / or HDF cladding panel having a pair of long sides and a pair of short sides with complementary assembly profiles,

[0010] formulation characterized in that it comprises

[0011] compounds of natural origin, immiscible with water, oily and covering, melted to be mixed while hot, mixture which, upon returning to room temperature, is in a solid state.

[0012] In particular, this coating formulation comprises a compound having the function of (a) penetrating and dissolving agent of the formulation, texturizer and drying agent, selected from the group comprising: triglycerides, hemp oil, sterol ester, perilla oil, linseed oil;

[0013] a compound having the function of a tackifying agent (b), selected from the group comprising: resin ester, terpene, shellac, gum arabic, mastic resin;

[0014] a compound having the function of a (c) melting temperature and hot viscosity control agent, selected from the group comprising: beeswax, camauba wax, glycerol ester, and

[0015] a compound having the function of cold texturizing agent (d) and antioxidant, camauba wax.

[0016] This coating formulation avoids the addition of additives such as fungicides, chemical antioxidants.

[0017] This coating formulation made from natural compounds makes it possible to make the assemblies of coating blades hydrophobic.

[0018] The coating of the upper supports does not interfere with the handling of the blades when the coating has cooled.

[0019] The penetration of the formulation into the upper supports of the blade is sufficient; it creates a flexible surface joint, once the coating has dried.

[0020] Particularly interestingly, in the coating formulation agent (a) is linseed oil, agent (b) is rosin, agent (c) is beeswax, agent (d) is camauba wax.

[0021] In the case of this combination, compounds a, b, c represent the respective weight proportions of between 40 and 50% for agent (a), between 20 and 30%, in particular between 22 and 28% for agent (b), between 20 and 25% for agent (c), between 4 and 6% for agent (d).

[0022] Where appropriate, the formulation also contains a compound having the function of texturizing agent (e) and melting temperature control agent, chosen from the group comprising: paraffin, paraffin wax, ozokerite wax in a weight ratio of 2 to 3% of the total mass of the formulation.

[0023] The invention also relates to a cladding blade having a pair of long sides and a pair of short sides with complementary assembly profiles, and the joining of the sides under the top decorated and non-permeable surface being made in the upper part of the profiles of the two blades by high bearing surfaces in the plane of joining the blades, above the assembly profiles proper which make the assembly by the form of two successive blades, this blade being characterized in that it comprises a coating of the high bearing surfaces with a coating formulation of natural origin compounds, immiscible with water, oily and covering, this coating combination being applied in the molten state and in particular a formulation such as defined above.

[0024] In general, the hydrophobic coating applied to the blade profile allows for a solid thickness but remains deformable, respecting the precision of the profile and guaranteeing ease of assembly.

[0025] This sealing layer compensates for any gaps in the joints due to manufacturing defects; it prevents the profile from swelling. Because the coating hardens quickly, this facilitates cleaning of the production line and prevents contamination of the line by dirt that could end up on the products.

[0026] Since the coating formulation is a combination of natural compounds, it It benefits from the multiple effects of this natural complexity without the harmful health effects of petroleum-based formulations. Furthermore, this coating formulation is important for the recycling of cladding boards.

[0027] The coating formulation, according to the invention, imposes temperature limits so as not to destroy the naturally occurring compounds, which in turn has the advantage of having to work at lower temperatures to avoid this destruction and thus results in savings compared to working at higher temperatures which would have to be applied to petroleum-based products.

[0028] The invention also relates to a method for preparing such a coating formulation, this method consisting of:

[0029] - heat the compounds to a melting temperature between 70°C and 85°C and particularly at 78°C, by mixing them and

[0030] - allow to cool to room temperature to obtain a coating formulation at the solid state.

[0031] Advantageously:

[0032] - the formulation is prepared in the molten state by adding the compounds in the order increasing from their respective melting points;

[0033] - each compound is added after the complete melting of the added compound previously and the temperature is raised according to the melting point of the compound to be added.

[0034] The invention also relates to a coating installation for applying a hydrophobic coating, as defined above, to the upper supports of cladding boards, and, where applicable, the short sides, this installation comprising:

[0035] - a melting pot receiving the coating formulation for its melting in the liquid phase,

[0036] - one or more coating heads installed on the blade transfer line,

[0037] - a pressurized liquid coating formulation supply, connecting the melting pot at each coating head and comprising:

[0038] * a pump connected to the melter

[0039] * a conduit connected to the coating head,

[0040] the equipment between the outlet of the melter and each coating head being maintained at a temperature close to the coating temperature.

[0041] In this coating installation, the temperature of the coating formulation in the coating head for its application on the blades is lower than the viscosity at which microdroplets appear during the projection of the formulation onto the blade.

[0042] This imposed coating temperature prevents the formation of mist during the application of the formulation to the blades, thus preventing or significantly reducing fouling of the profile machining equipment by mist condensate. Brief description of the drawings

[0043] The present invention will be described in more detail below with reference to an embodiment of a coating blade and a method for applying the coating, shown in the accompanying drawings in which:

[0044] [Fig-1] section of a blade according to the invention showing the shape of the long sides,

[0045] [Fig.2] diagram of the coating installation.

[0046] DESCRIPTION OF AN IMPLEMENTATION METHOD

[0047] According to [Fig. 1], the invention relates to a rectangular thin-walled cladding board 1, made of HDF or MDF, intended for installation in parallel rows. The board 1 has a pair of long sides and a pair of short sides, each consisting of complementary profiles LG, RG which allow the long side LG, having a tongue, to be joined to the other long side RG, having a groove; the short sides with complementary profiles (not shown) are assembled by snapping when the board 1 is inserted in an inclined position by its tongue 23 into the groove 13 of a row of boards 1' in the row already installed and is folded down into the installation plane to engage and hook onto the sides with aligned grooves RG of boards in the row already installed; this tilting movement causes the short side to snap into the short side of the corresponding profile of the previous board in the row being installed.

[0048] The profiles of the long sides LG, RG are cross-section profiles of a blade.

[0049] Fig. 1 shows two blades 1, 1 joined by the profile on the LG side of one blade 1 engaged and locked in the profile on the RG side of the other blade 1, with the indication of the junction plane PJ perpendicular to the laying plane which is that of the underside 1b of the blades.

[0050] The profile of the large side RG comprises, from top to bottom, from the top to the bottom, 1b of the blade:

[0051] - a high support 11 located in the junction plane PJ,

[0052] - a groove 13 and then,

[0053] - an advance of 14,

[0054] - a hydrophobic coating 15 of the upper support 11.

[0055] The profile of the long side LG of the blade 1, whose shape is complementary to that of the long side RG, comprises, from top to bottom, 1b:

[0056] - a high support 21 in the junction plane PJ continuing as follows:

[0057] - a rounded tab 23,

[0058] - a hydrophobic coating of the upper support 25.

[0059] The meeting of the profiles of the LG / RG sides results in particular in the contact between the hydrophobic coatings 15, 25 of the upper supports 11, 21.

[0060] The coating 15, 25 is a bead of coating applied in a molten, hot state to the upper supports 11,21 on both sides of the blade 1.

[0061] The hydrophobic coating is a combination of water-immiscible, oily and covering compounds, forming a dry and flexible film adhering to the surface of the high supports 11,21 and also constituting a waterproof layer.

[0062] Thus, the coating is a combination of compounds having the following functions respectively:

[0063] - agent (a): penetration, melting and texturizing function,

[0064] - agent (b): tackifying function,

[0065] - agent (c): fluxing function, melting temperature control and viscosity when hot,

[0066] - agent (d): cold texturizer and antioxidant function.

[0067] Agents a, b, c, d are chosen from groups of compounds having partly analogous properties:

[0068] agent (a): selected from the group comprising: triglycerides, hemp oil, sterol esters, perilla oil, linseed oil,

[0069] agent (b): selected from the group comprising: resin esters, terpenes, shellac, gum arabic, mastic resin,

[0070] agent (c): selected from the group comprising: beeswax, glycerol esters,

[0071] agent (d): camauba wax.

[0072] And more specifically, the coating is a combination of the following agents (a, b, c, d), providing the particular characteristics through synergy between the compounds:

[0073] agent (a): linseed oil.

[0074] Its function as a penetrating agent improves the penetration of the coating into the wood. It thins the solution when hot and promotes the dissolution of the other compounds into a single phase. It is a drying agent, meaning it dries by polymerization, hardening upon contact with air and wood, forming a dry and flexible film that retains the other compounds.

[0075] agent (b): rosin.

[0076] Its tackifying agent function improves immediate adhesion to a substrate, i.e., the material of the blade and the stability of the formulation.

[0077] agent (c): beeswax.

[0078] Its function is that of a flux to control the melting temperature and hot viscosity. Its melting temperature is the lowest among the coating compounds; it controls the melting temperature by its proportion in the overall formulation and the viscosity of the formulation in the molten state.

[0079] agent (d): camauba wax.

[0080] Its function is that of a texturizing agent in its molten state, providing a certain viscosity that is advantageous for projecting the formulation onto the surface to be covered, preventing the formation of microdroplets that create a mist. In this respect, its function is analogous to that of rosin, but it allows for more flexible control because, conversely, the precision of the rosin formulation is very critical.

[0081] Depending on the case, the coating formulation is supplemented by a heterogeneous agent (e), which is microcrystalline wax (derived from petroleum). This microcrystalline wax acts as a texturizing agent and controls the melting temperature, and also has a supercooling effect; it maintains the melting state at a temperature below the melting temperature, preventing phase separation of the formulation, i.e., the premature precipitation of one compound while the others remain in the liquid state.

[0082] The above compounds are preferably combined in the following weight percentages relative to the total mass:

[0083] agent (a) in particular linseed oil, percentage between 40 and 50%,

[0084] agent (b) in particular rosin, combined in a proportion of 20 to 30%, and in particular 22 to 28%.

[0085] agent (c) in particular beeswax, combined in a proportion of 20 to 25%.

[0086] agent (d) combined camauba wax according to 4 to 6%.

[0087] agent (e) microcrystalline paraffin wax added at 2 to 3% to allow a precise control of the melting temperature.

[0088] The manufacturing process for the coating formulation is carried out under the following conditions:

[0089] - heat the compounds to a melting temperature between 70°C and 85°C and particularly at 78°C, by mixing them and

[0090] - allow to cool to room temperature to obtain a coating formulation at the solid state.

[0091] In particular, according to the process, the formulation is prepared in the molten state by successively adding the compounds in increasing order of their respective melting temperatures:

[0092] - a compound is added after the complete melting of the previously added compound and we raise the temperature according to the melting point of this newly added compound.

[0093] The cooled formulation, in solid state, is waiting to be used later according to the needs of the coating installation to be melted and feed the coating head.

[0094] Figure 2 shows a diagram of a coating installation 200 for precisely applying a hydrophobic coating to the upper supports 11, 21 of the profiled sides of the coating blade 1 coming from the machining stations 51, 52 on a transfer line 220 equipped with a sensor 221 that detects the presence and passage of a blade 1 to control the coating. The blades 1 arrive from the machining station discontinuously, blade by blade, the presence of which (front end, rear end) must be detected to control the activation and deactivation of the nozzles 213, 213a which apply the coating to one or two sides of the blade 1 to obtain the blade 1' at the output.

[0095] The blades 1 are guided and driven precisely in their movement in the coating installation 220 to allow precise and homogeneous coating; for example, the surfaces to be coated have a height ranging from 0.5 mm to 4 mm and the coating nozzles have, for example, a circular orifice with a diameter ranging from 0.2 to 0.7 mm; the nozzles are spaced from the sides of the blades at distances of 15 to 150 mm.

[0096] The coating head(s) 213, 213a are installed on either side of the transfer line 220.

[0097] The installation 200 includes a melter 210 which receives the coating formulation in solid state. The melter melts the formulation and keeps it in liquid phase to supply each coating head 213, 213a equipped with a nozzle which applies the coating formulation exactly onto the upper supports of the blades 1 which pass through the installation.

[0098] The melter 210 operates at the lowest possible melting temperature to maintain the homogeneity of the molten and liquid formulation during its transfer and application by the coating heads 213, 213a, maintaining the formulation at a sufficient viscosity to avoid the production of microdroplets that cause the formation of fog which is disruptive to the operation of the installation and its cleaning.

[0099] Each coating head 213, 213a is connected to the melter 210 by a pump 211 at the melter outlet which supplies the coating heads 213, 213a by a conduit 212, 212a provided with insulation 214, 214a.

[0100] The pump 211 pressurizes the coating liquid. The coating head 213, 213a opens for an opening time that is dynamically adjusted according to the speed of the blade 1.

[0101] The coating is applied along the length of the blade but it can also be applied, if necessary, to the width of the blades.

[0102] The operation of the installation 200 is managed by a control unit 250 possibly integrated into the overall control of the blade manufacturing installation.

[0103] The control unit 250 receives the control signals Sx representing the operating parameters such as the outside temperature, the operating temperature of the melter 210 and the coating heads 213, 213a, the general parameters of the blades (dimensions, height of the upper supports 11,12 etc).

[0104] It also receives the global control signal Sy from the entire installation and emergency stops.

[0105] The sensor 221 provides the specific signals, relating to each blade 1, moving along the transfer line 220 corresponding dynamically to the instantaneous position of the blade 1 and its speed of movement, to precisely activate the start and end of the opening of the nozzle of each coating head 213, 213a; the control of their supply by the pump 211, and the temperature of the melter 210 so that the application temperature is constant and the appropriate viscosity avoids the formation of microdroplets generating mist.

[0106] The control unit 250 emits control signals C210, C211, C213, C213a to control the operation and temperature / temperature rise of the melter 210, the operation of the pump 211 for supplying coating liquid at the pressure which, depending on the operating state of the nozzles, is the control of the stopping / closing of the nozzles 213, 213a.

[0107] NOMENCLATURE OF PRINCIPAL ELEMENTS

[0108] 1 Blade

[0109] 1 ' Coated blade

[0110] the top of the blade

[0111] 1b Underside of the blade

[0112] LG Large side: tongue profile

[0113] RG Large side: grooved profile

[0114] PJ Junction Plan

[0115] 11 High support

[0116] 12 Chamfer

[0117] 13 Groove

[0118] 14 Extension

[0119] 15 Hydrophobic coating of the upper support 11

[0120] 21 High support

[0121] 22 Chamfer

[0122] 23 Tongue

[0123] 25 Hydrophobic coating of the upper support 21

[0124] 51 Machining station

[0125] 52 Machining station

[0126] 200 Coating installation

[0127] 210 Melting Room

[0128] 211 Pump

[0129] 212- 212a Conduct

[0130] 213 - 213a Coating head

[0131] 214- 214a Pipe insulation

[0132] 220 Transfer line

[0133] 221 Scroll sensor

[0134] 250 Control Unit

[0135] S221 Sensor signal

[0136] Sx General Settings

[0137] Sy Input control signal

[0138] C210 Melter control

[0139] C211 Pump control

[0140] C213 - C213A Coating head control signal

[0141] MDF Medium Density Fiberboard

[0142] MHF High-density fiberboard

Claims

Demands

1. Hydrophobic coating formulation for an MDF and / or HDF cladding board having a pair of long sides and a pair of short sides with complementary assembly profiles, formulation characterized in that it comprises natural, water-immiscible, oily and covering compounds, melted to be mixed while hot, mixture which, upon returning to room temperature, is in a solid state.

2. A coating formulation according to claim 1, characterized in that it comprises: - a compound having the function of an agent (a) penetrating and dissolving the formulation, texturizing and drying agent, this agent (a) being selected from the group comprising: triglycerides, hemp oil, sterol ester, perilla oil, linseed oil, - a compound having the function of a tackifying agent (b), selected from the group comprising: resin ester, terpene, shellac, gum arabic, mastic resin, - a compound having the function of an agent (c) controlling the melting temperature and hot viscosity, selected from the group comprising: beeswax, carnauba wax, glycerol ester, and - a compound having the function of a cold texturizing and antioxidant agent (d), being carnauba wax.

3. Coating formulation according to claim 2, characterized in that - agent (a) is linseed oil, - agent (b) is rosin, - agent (c) is beeswax, - agent (d) is carnauba wax.

4. Coating formulation according to claim 3, characterized in that compounds a, b, c, d are combined, in the respective weight proportions, between 40 and 50% for agent (a), between 20 and 30% in particular between 22 and 28% for agent (b), between 20 to 25% for agent (c), between 4 to 6% for agent (d).

5. Coating formulation according to claims 1 to 4, characterized in that it also contains a compound having the function of texturizing agent and melting temperature control agent, chosen from the group comprising: paraffin, paraffin wax, ozokerite wax in a weight ratio of 2 to 3% of the total mass of the formulation.

6. A method for preparing a hydrophobic coating formulation according to any one of claims 1 to 5, consisting of - heating the compounds to a melting temperature between 70°C and 85°C and in particular to 78°C, mixing them and - allowing them to cool to room temperature to obtain a coating formulation in the solid state.

7. A preparation method according to claim 6, characterized in that - the formulation is prepared in the molten state by adding the compounds in increasing order of their respective melting temperatures: - each compound is added after the complete melting of the compound added previously and the temperature is raised according to the melting temperature of this new compound to be added.

8. MDF and HDF cladding board having a pair of long sides and a pair of short sides with complementary assembly profiles, - the joining of the sides under their upper surfaces (la) decorated and non-permeable being made in the upper part of the profiles of the two boards by bearing surfaces (11, 21) in the joining plane (PJ) of the boards, above the assembly profiles proper which make the assembly by the form of two successive boards, characterized in that the bearing surfaces (11, 21) are covered with a formulation made up of compounds of natural origin, immiscible with water, oily and covering, according to any one of claims 1 to 5 and applied in the molten state.

9. Coating installation (200) for applying a hydrophobic coating formulation to the upper supports (11, 21) of a cladding blade (1) according to any one of claims 1 to 5, characterized in that it comprises - a melter (210) receiving the coating formulation for its melting in the liquid phase, - at least one coating head (213) installed on the transfer line (220) of the blades (1), - a pressurized liquid coating formulation supply, connecting the melter (210) to each coating head (213) and comprising: * a pump (211) connected to the melter (210) and supplying a * a line (212) connected to the coating head (213), the equipment between the outlet of the melter (210) and the coating head (213) being maintained at a temperature close to the coating temperature.

10. Coating installation (200) according to claim 9, characterized in that the coating temperature of the coating formulation in each coating head (213) for its application on the blades (1) is lower than the viscosity at which microdroplets appear during the projection of the formulation onto the blade.

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