INDUSTRIAL FLOOR COMPRISING A RELIEF-STYLE METAL SHEET

Abstract

The invention relates to a floor (30), particularly for industrial vehicles, comprising a textured sheet (10) having on its upper face (11) a plurality of raised patterns, each raised pattern comprising one or more projecting parts (20), said raised patterns being arranged periodically, discreetly, and in an orderly fashion, the height h of said raised patterns being between 0.3 and 3 mm, and on its lower face (12) a rough-rolled surface with a maximum roughness Rmax of less than 8 µm, a wooden support (30) characterized in that the lower face of the textured sheet is bonded to the wooden support with a two-component, unbaked adhesive (31) comprising a resin component including at least an epoxy resin and a hardening agent component, and its manufacturing process. The use of a floor according to the invention in an industrial vehicle, preferably a refrigerated vehicle, is advantageous. Abstract figure: Fig. 2

Description

Title of the invention: INDUSTRIAL FLOOR COMPRISING A RELIEF-STYLE METAL SHEET technical field

[0001] The invention relates to an industrial floor comprising a metal sheet having on one of its faces a plurality of relief patterns arranged periodically, each pattern itself consisting of one or more protruding parts, which we will call "reliefs" and a wooden support. Previous art

[0002] Numerous models of sheet metal with repetitive embossed patterns, or "embossed sheets," are already available on the market. According to standard EN12258-1, the term "embossed sheet metal" refers to a sheet "printed with an embossed pattern on one face by rolling." These patterns are described, for example, in standard NF-EN-1386 and are often referred to evocatively (checkerboard, barleycorn, almond, diamond, rice grain, checkerboard 2, checkerboard 5, etc.). The "checkerboard 5" pattern, also called "quintet," frequently used for industrial flooring, features a group of five elongated, semi-ovoid, parallel bumps surrounded by four identical groups, each derived from the first group by a 90° rotation. Sheet metal with this "quintet" pattern is highly wear-resistant but has only average anti-slip properties. Fig. 1 represents a relief plate according to standard EN1386.The height of the raised pattern is the difference, h, between the maximum thickness measured to the top of the pattern and the thickness t of the adjacent area without relief.

[0003] The "rice grain" pattern, described in patent FR 2 747 948, is also used for the production of aluminum alloy sheets for industrial floors, which have satisfactory performance properties, in particular because they have good wear resistance and offer friction contact conditions which allow pedestrians to walk without risk of slipping and trolleys to roll without skidding.

[0004] Patent application WO2011 / 121191 describes a metal sheet for the making of floors, in particular of industrial vehicles, on which trolleys are to circulate, having a plurality of patterns, the reliefs of which have a maximum height of between 0.2 and 1.5 mm and a friction surface, which has, whatever the direction in which it is measured, an average width of at least 1 mm.

[0005] Patent application WO2020 / 180386 describes methods for treating metallic substrates and articles comprising a phosphonate functionalized layer.

[0006] Patent application WO2022074320 relates to a metal sheet for flooring, particularly for industrial vehicles, said sheet having on its upper surface a plurality of embossed patterns, each embossed pattern comprising one or more protruding parts, said embossed patterns being arranged periodically, discreetly, and in an orderly fashion, the height of said embossed patterns being between 0.3 and 3 mm, characterized in that it has on its lower surface, intended to be bonded to a substrate, a rough surface with a maximum roughness (Rmax) of between 10 mm and 250 mm. In this document, the tests were carried out after bonding with a well-known polyurethane adhesive, "Korapür 666," a trademark.

[0007] The embossed sheets have on the upper face, intended to form the floor and to be in contact with persons or handling vehicles used for example in the industrial vehicle, said repetitive embossed patterns.

[0008] The underside of the embossed sheet metal is most often bonded to a substrate, for example, a wooden board typically made of plywood, to form the floor of the industrial vehicle. To obtain sufficient adhesion between the underside of the sheet metal and the substrate, a surface treatment is carried out, according to the prior art, typically involving degreasing and the application of a primer, such as a varnish. This treatment is effective; however, it necessitates additional operations, resulting in a high cost.

[0009] The flooring must withstand the poultice test. The poultice test was originally developed for steel and has gradually become the standard for evaluating bonding performance, even for assemblies including aluminum alloy sheets. For the production of wood and aluminum flooring, the poultice test is considered one of the most stringent bonding requirements. The poultice test consists of an overlap shear test (e.g., according to EN-1465 or ISO-4587) after aging the samples under harsh conditions, such as several days at 70°C in saturated humidity (100% RH) followed by freezing conditions such as -20°C for several hours.

[0010] The problem that the present invention seeks to solve is to obtain a floor comprising a textured sheet and wood and having improved adhesion, particularly resistant to the poultice test, without requiring a surface treatment operation and deposition of a primary adhesion layer or an operation significantly modifying the roughness of the underside of the textured sheet, with an economical process. Description of the invention

[0011] A first object of the invention is a floor, in particular of industrial vehicles, comprising a relief sheet having on its upper face a plurality of relief patterns, each relief pattern comprising one or more protruding parts, said relief patterns being arranged in a periodic, discreet and orderly manner, the height h of said relief patterns being between 0.3 and 3 mm and on its lower face a rough rolling surface with a roughness Rmax less than 8 pm, a wooden support characterized in that the lower face of the relief sheet is glued to the wooden support with a two-component, non-baking adhesive comprising a resin component comprising at least an epoxy resin and a hardening agent component.

[0012] A second object of the invention is a method for manufacturing a floor comprising (i) a rolling step using an engraved rolling cylinder having engraved cavities to obtain a relief sheet having raised patterns on its upper face, and a rough rolled surface with a roughness Rmax of less than 8 pm on its lower face, (ii) a step of non-baking bonding the underside of the relief sheet thus obtained to a wooden support with a non-baking two-component adhesive comprising a resin component including at least an epoxy resin and a curing agent component.

[0013] Yet another object of the invention is the use of a floor according to the invention or obtained by the process according to the invention in an industrial vehicle, preferably a refrigerated vehicle. Figures

[0014] Fig. 1 is a schematic cross-sectional representation of a relief sheet useful for the floor according to the invention.

[0015] Fig. 2 is a schematic cross-sectional representation of a floor according to the invention.

[0016] Fig. 3 is a schematic representation of the overlap shear test.

[0017] Fig. 4 is a presentation of the results of Example 1.

[0018] Fig. 5 is a presentation of the results of Example 2. Detailed description of the invention

[0019] The floor according to the invention, typically a vehicle floor, comprises a textured sheet metal bonded to a wooden support. According to the common definition, sheet metal is a rolled product with a generally rectangular cross-section and an average thickness not exceeding 1 / 10th of its width. The floor is the part of a construction or of a vehicle that constitutes a horizontal platform, the upper face of which forms the ground. The roughness parameter Rmax is defined as the greatest difference between the highest peak and the lowest trough over the analyzed length. The analyzed length has a direction perpendicular to the rolling direction of the sheet and has a value dependent on the Rmax value as described below: 0.025 pm < Rmax < 0.1 pm typical analyzed length: 0.08 mm 0.1 pm < Rmax < 0.5 pm typical analyzed length: 0.25 mm 0.5 pm < Rmax < 10 pm typical analyzed length: 0.80 mm 10 pm < Rmax < 50 pm typical analyzed length: 2.50 mm 50 pm < Rmax < 250 pm typical analyzed length: 8.00 mm.

[0020] The parameter Rmaxest is notably mentioned in the BS 1134 2010 A2 standard in which the above definitions can be supplemented if necessary.

[0021] The embossed sheet metal of the floor according to the invention has, on its upper surface, intended to form the upper surface of the floor, embossed patterns comprising one or more protruding parts which, like the unit cell of a crystal lattice, repeat periodically and in an ordered manner. An embossed pattern is therefore a piece of sheet metal that repeats indefinitely by translation along two directions of the plane of the sheet metal. This piece of sheet metal may comprise only one protruding part, but it may also comprise several protruding parts which may have different shapes or orientations. It does not appear advantageous to have protruding parts of different heights, but this is not excluded a priori. The height h of these embossed patterns is between 0.3 mm and 3 mm. The height of the embossed pattern is the difference, h, between the maximum thickness measured to the top of the pattern and the thickness t of the adjacent area without relief.Advantageously, particularly with regard to embossed aluminum alloy sheets, it is between 0.3 and 1.5 mm, preferably between 0.4 and 0.8 mm.

[0022] These patterns are also repeated discreetly, as such a configuration is favorable to the anti-slip properties of the floor. Indeed, the raised areas act as indenters on the surface of the sole or tread of the wheel: under the weight of the pedestrian or trolley, the surface deforms and "sinks" around the raised area to a certain height, on the order of one, two, or three tenths of a millimeter. A discontinuous raised area promotes the formation of a ridge around the top edge of the sole or tread, which facilitates the "grip" of the sole, tread, or tire on the floor. Furthermore, discreetly repeating patterns facilitate cleaning, as the flow and removal of fluids are more efficient. easy. The embossed sheet metal of the floor according to the invention must therefore not have a continuous relief.

[0023] The raised patterns on the upper face are obtained by rolling using an engraved rolling cylinder characterized in that it has engraved cavities allowing the raised patterns to be obtained on the sheet metal.

[0024] The underside of the embossed sheet metal, intended to be bonded to a wooden substrate, has a rough rolling surface with a maximum roughness (Rmax) of less than 8 µm, advantageously at most 5 µm and preferably at most 3 µm. In one embodiment, the maximum roughness (Rmax) of the underside is from 0.1 µm to 6 µm and preferably from 0.5 µm to 3 µm.

[0025] The present inventors have observed that by using a two-component, no-bake adhesive comprising a resin component including at least one epoxy resin and a curing agent component, it is possible to obtain excellent poultice test results without surface treatment or modification of the roughness of the underside of the embossed sheet metal. The two-component, no-bake adhesive comprising a resin component including at least one epoxy resin and a curing agent component cures at room temperature, which is typically in the range of approximately 5 to 40 °C, preferably approximately 10 to 35 °C. Curing begins with the mixing of the two components by means of a chemical reaction. Bonding is typically carried out under vacuum or using a hydraulic press, the platen of which may optionally be heated to 50 °C or 60 °C.Curing occurs at room temperature and typically takes from a few hours to a few weeks, for example, between 1 and 7 days. The duration depends, among other things, on the temperature, the reactivity of the components and their stoichiometry, as well as the presence of accelerators. Thus, unlike some one-component epoxy adhesives, for example, no curing oven is required, which notably makes the manufacturing process more efficient. Surprisingly, two-component, no-cure adhesives, comprising a resin component with at least one epoxy resin and a curing agent component, can bond to a non-degreased surface and appear to absorb surface oil. Preferably, the curing agent in the adhesive contains amines.

[0026] Advantageously, the raised floor plate according to the invention is an aluminum alloy plate. Advantageously, the plate is made of an aluminum alloy belonging to the group comprising aluminum alloys of the Ixxx, 3xxx, 5xxx, and 6xxx series according to the Aluminum Association designation, as well as alloys of the 7xxx series, comprising less than 0.4% Cu. Preferably, the alloy is selected from the list consisting of AA1050A, AA3003, AA3103, AA5026, AA5052, AA5083, AA5086, AA5754, AA6061, AA6082, and AA7020.

[0027] Fig. 1 schematically represents a relief plate 10 of the floor according to the invention having on its upper face 11 a relief pattern comprising a projecting part 20, of height h and on its lower face 12, a rough rolling surface with a roughness Rmax less than 8 pm.

[0028] Fig. 2 schematically represents a floor 30 according to the invention comprising a relief sheet 10 glued onto a wooden support 32 using a two-component, non-baking adhesive 31 comprising a resin component including at least an epoxy resin and a hardening agent component.

[0029] The method for manufacturing floors according to the invention comprises (i) a rolling step using an engraved rolling cylinder having engraved cavities to obtain a relief sheet 10 having relief patterns 20 on its upper face 11, and a rough rolling surface with a roughness Rmax less than 8 pm on its lower face 12, (ii) a step of non-baking bonding the lower face of the relief sheet thus obtained to a wooden support 32 with a non-baking two-component adhesive 31 comprising a resin component including at least an epoxy resin and a curing agent component.

[0030] The two steps are carried out successively, without an intermediate step such as surface treatment, varnishing or electrochemical milling treatment, mechanical milling, brushing, or deformation typically sandblasting, shot blasting, rolling, embossing, debossing allowing to modify the roughness of the underside.

[0031] The amount of rolling oil on the underside after step (i) and during step (ii) is 0.05 to 4 g / m² and preferably 0.1 to 3 g / m². In one embodiment, the amount of rolling oil on the underside is at least 0.1 g / m², 0.2 g / m², 0.3 g / m², 0.4 g / m², 0.5 g / m², 0.6 g / m², or 0.7 g / m². In another embodiment, the amount of rolling oil on the underside is at most 4 g / m², 3 g / m², or 2 g / m².

[0032] The bonding step is carried out without baking the two-component, no-bake adhesive comprising a resin component including at least one epoxy resin and a curing agent component. The components are mixed using a suitable process, which can be carried out continuously or in batches. If mixing does not take place immediately before application, care must be taken to ensure that not too much time elapses between mixing the components and application. Mixing takes place at ambient temperature, which is typically in the range of about 5 to 40 °C, preferably about 10 to 35 °C. Curing begins with the mixing of the two components by means of a chemical reaction, as described above. Bonding is typically carried out under vacuum or using a hydraulic press. The platform can optionally be heated to 50°C or 60°C. Curing takes place at room temperature and typically lasts from a few hours to a few weeks, for example, between 1 and 7 days. The duration depends, among other things, on the temperature, the reactivity of the components and their stoichiometry, as well as the presence of accelerators. Thus, after step (ii), the resulting floor is not typically heated above 40°C. The absence of baking is advantageous for the simplicity of the process.

[0033] The use of the floors according to the invention in an industrial vehicle, preferably a refrigerated vehicle, is particularly advantageous. Examples

[0034] Example 1

[0035] In this example, the adhesion performance of a 2.5 mm thick AA5086 alloy sheet was compared. The sheet had a rice grain pattern relief on its upper surface, as defined in standard NF EN 1386, and a cold-rolled roughness on its lower surface, with a maximum roughness (Rmax) of less than 3 pm and a rolling oil content of 0.8 g / m². Samples were prepared according to the prior art by applying an adhesion primer to the lower surface.

[0036] Samples of sheet metal measuring 100x25 mm were glued rough rolling face to rough rolling face using several glues over a joint length of 16.5 mm. A: Lord® 852 / 25 GB Acrylic Glue B: Sikaforce® 422 polyurethane adhesive C: Dunapol® AD1670 polyurethane adhesive D: Two-component, no-bake adhesive comprising an epoxy resin and a BETAMATE™ 2090 BPA-free curing agent

[0037] A test was also carried out with the polyurethane glue “Korapür 666”, trademark, but the result after the poultice test was not even favorable with adhesion primer (adhesive failure).

[0038] Some samples underwent aging for 14 days in a poultice at 70°C saturated with 100% humidity and for 15 hours at -20°C. Mechanical performance and fracture morphology were evaluated on the original and aged samples using an overlap shear test (e.g., according to EN-1465 or ISO-4587). To pass the test, several criteria must be met, such as the maximum loss value and / or the absence of adhesive failure.

[0039] The results obtained are presented in Table 1 and in [Fig.4]. When the break occurs within the wood or within the glue, the break is said to be cohesive. When the break occurs at the interface between the sheet metal and the glue, the break is said to be adhesive.

[0040] The two-component, non-baking adhesive D, comprising an epoxy resin and a curing agent, exhibits the best results without an adhesion primer, whether after bonding or after a poultice test.

[0041] [Tables 1] Metal-to-metal bonding After bonding After plaster test Loss factor Adhesive primary adhesion Shear strength (MPa) Failure Shear strength (MPa) Failure A No 18 Cohesive 13 Cohesive 28% A Yes 17 Cohesive 18 Cohesive -6% B No 16 Adhesive 4 Adhesive 75% B Yes 20 Cohesive 20 Cohesive 0% C No 7 Adhesive 2 Adhesive 71% C Yes 17 Cohesive 18 Cohesive -6% D No 24 Cohesive 20 Cohesive 17% D Yes 23 Cohesive 18 Cohesive 22%

[0042] Samples of sheet metal measuring 100x25 mm were also glued to the rough rolling face on the face of the plywood boards using the same glues over a joint length of 16.5 mm.

[0043] The rupture results are presented in Table 2

[0044] [Tables2] Metal / Wood Bonding Adhesive Primer Bonding Failure A Non-Adhesive A Yes Adhesive B Non-Cohesive B Yes Cohesive C Non-Adhesive C Yes Cohesive D Non-Cohesive D Yes Cohesive

[0045] Acrylic A glue did not allow for cohesive break, with or without adhesion primer for wood / metal type bonding, which disqualifies it for the intended application.

[0046] Example 2

[0047] In this example, the adhesion performance of a 2.5 mm thick AA5086 alloy sheet was compared. The upper surface had a rice grain pattern relief, as defined in standard NF EN 1386, while the lower surface had a cold-rolled roughness with an Rmax roughness of less than 3 µm. All samples were degreased, and then a quantity of 1 to 6 g / m² of an industrial lubricant was applied to the surface to simulate, under reproducible conditions, the effect of the amount of residual rolling oil. Samples measuring 100 x 25 mm were bonded, cold-rolled surface to cold-rolled surface, using the two-component epoxy adhesive BETAMATE™ 2090 BPA-free, with a joint length of 16.5 mm.

[0048] Some samples underwent aging for 14 days in a poultice at 70 °C saturated with humidity (100%) and 15 hours at -20 °C. The mechanical performance and fracture morphologies are evaluated on the original and aged samples after an overlap shear test (for example according to EN-1465 or ISO-4587).

[0049] The results are given in Table 3 and in [Fig.5].

[0050] [Tables3] After bonding, after poultice test, loss factor, adhesive, lubricant quantity (g / m²), shear strength (MPa), failure, shear strength (MPa), failure. D1 21 Cohesive 20 Cohesive 5% D2 20 Cohesive 19 Cohesive 5% D3 19 Cohesive 20 Adhesive -5% D4 20 Cohesive 18 Cohesive 10% D5 17 Cohesive 16 Cohesive 6% D6 22 Cohesive 15 Adhesive 32%

[0051] The results obtained are satisfactory up to a lubricant weight of 4 g / m2.

Claims

Demands

1. Floor (30), in particular of industrial vehicles, comprising a relief plate (10) having on its upper face (11) a plurality of relief patterns, each relief pattern comprising one or more projecting parts (20), said relief patterns being arranged in a periodic, discrete and orderly manner, the height h of said relief patterns being between 0.3 and 3 mm and on its lower face (12) a rough rolling surface with a roughness Rmax less than 8 pm, a wooden support (30) characterized in that the lower face of the relief plate is glued to the wooden support with a two-component, non-baking adhesive (31) comprising a resin component comprising at least an epoxy resin and a curing agent component.

2. Floor according to claim 1 in which the roughness Rmax of the lower face (12) is at most 5 pm and preferably at most 3 pm.

3. Floor according to claim 1 or claim 2 wherein the embossed sheet is made of an aluminum alloy belonging to the group comprising aluminum alloys of the Ixxx, 3xxx, 5xxx, 6xxx series according to the designation of the Aluminium Association as well as alloys of the 7xxx series, comprising less than 0.4% Cu.

4. Flooring according to any one of claims 1 to 3 wherein the curing agent component of the two-component, no-bake adhesive comprises amines.

5. A method for manufacturing a floor (30) according to any one of claims 1 to 4 comprising i. a rolling step using an engraved rolling cylinder having engraved cavities to obtain a relief sheet (10) having relief patterns (20) on its upper face (11), and a rough rolling surface with a roughness Rmax of less than 8 pm on its lower face (12), ii. a step of non-baking bonding the lower face of the relief sheet thus obtained to a wooden support (32) with a non-baking two-component adhesive (31) comprising a resin component comprising at least an epoxy resin and a curing agent component.

6. A method according to claim 5 wherein the quantity of a rolling oil on the underside at the end of step (i) and during step (ii) is 0.05 to 4 g / m2 and preferably 0.1 to 3 g / m2.

7. A method according to claim 5 or claim 6 wherein in step (i) the rolling step is carried out so that the roughness Rmax of the lower face (12) is at most 5 pm and preferably at most 3 pm.

8. Use of a floor according to any one of claims 1 to 3 or obtained by the process according to any one of claims 5 to 7 in an industrial vehicle, preferably a refrigerated vehicle.

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