FR2500025A1 - Reinforced particulate rubber strip for laying sports surfaces - prefabricated for laying as consistent long strips from rolls - Google Patents

Abstract

A prefabricated sports surface comprises a flexible sheet of resin bonded particles of chopped natural or polyurethane rubber incorporating a layer of mesh of strong, inextensible filaments as reinforced adjacent to the underside of the sheet. Typically the sheet is 3-15 mm thick and the reinforcement mesh is of glass coated with PVC or of synthetic filament of similar strength and stiffness. The mesh pores are 3-10 mm across, pref. are slightly larger than the chopped rubber particles. Thick sheets may be laid up in two more layers, opt. of contrasting colours, e.g. using relatively cheap black rubber for a reinforced substrate and red or green particles for a superficial layer: opt. additional reinforcement may be included at the layer interface. Suitable for laying tennis courts or other surfaces using strips typically 100 m long and 2.4 or 3 m wide. Stronger than unreinforced sheets, requires less delicate handling during lay-up. Prefabrication avoids interference with build-up or curing conditions by external variations in temp., dampness etc.

Description

 The subject of the present invention is coatings of improved quality capable of being used in particular for the construction of outdoor or undercover sports areas.

 We know coatings for sports fields in the form of a compressible elastic sheet made from waste natural or synthetic rubber, polyurethane or other grains of a similar synthetic material, which grains are connected and agglomerated together by a suitable binder of the polyurethane type in particular.

 These coatings, when correctly placed on a properly prepared bituminous base support or in cellular concrete have many and undeniable qualities. On the other hand, the technique of their implementation is relatively delicate and they are relatively fragile in particular if one evolves there with unsuitable shoes.

 On the other hand, when it comes to constituting open-air land, one is dependent on the weather conditions of the moment to proceed with the laying in good conditions of the coating, which strikes the cost prices and constitutes a handicap serious for the establishment of the installation schedule.

 The conventional manufacturing technique consists in spreading onto the underlying base support previously and suitably prepared (bituminous coating or cellular concrete in particular) a paint or synthetic adhesive for adhesion on which a mixture of synthetic elastic grains and a suitable binder ensuring, after polymerization, the good resistance of the elastic granular layer on the underlying support. This in situ manufacturing technique requires experience and good know-how, while the quality of the product obtained also depends on current weather conditions (humidity, temperature, etc.).

 In order to avoid these constraints, attempts have been made to produce coatings in the form of a compressible elastic sheet which can be rolled out on the spot based on elastic grains agglomerated together by a binder, said sheet being manufactured in the factory. Polymerized rubber cylinders were thus produced which were then cut and unrolled into sheets according to a technique close to the preparation of veneers by unrolling wooden balls. This technique is complicated, uses very expensive manufacturing machines and gives mediocre results as to the quality of the sheet obtained which also has internal stresses originating from its manufacturing process.

 The invention relates to a new improved coating allowing simple factory manufacture of a high quality product, the installation of which will be facilitated and the performance of use improved.

 According to a characteristic of the invention, the coating being in the form of an elastic compressible sheet which can be rolled out on site based on waste of natural or synthetic rubber, polyurethane or other grains of a similar synthetic material connected and agglomerated together by a suitable binder of the mono or bi-component polyurethane type, polyols, polyether and toluene diisocyanate is characterized in that it is formed on a lattice or mesh reinforcement embedded in it on its underside, substantially rigid, non-elastic, very resistant mechanically. Advantageously, said reinforcement is formed by a mesh with fine meshes of crossed glass fibers coated with PVC or synthetic fibers of equivalent mechanical quality. With such a structure, the elastic properties of compressibility of the coating are preserved, giving it the comfort of desired use, but a mechanical resistance is obtained simultaneously opposing in particular the tearing.

 The invention also relates to a method of manufacturing a said coating sheet, the method being characterized in that said sheet is formed on a plane factory manufacturing area, said area being previously covered with a sheet, by example of a non-stick geotextile based on polypropylene or polyester, on which said reinforcement is placed and over which said elastic sheet of elastic grains agglomerated by a binder and comprising one or more layers is formed. In this way, it is possible to manufacture in the factory, under cover and in well-defined ambient conditions, a product of very improved quality, far superior to the coatings produced according to the conventional technique in situ.

 According to another characteristic of the invention, the laying of a first lost layer is carried out on said manufacturing area without intermediate insertion of an anti-adhesion sheet, which makes it possible to radically eliminate all the manufacturing defects due to surface defects in the work area. Advantageously, the operation is repeated several times by forming several sheets superimposed on the same area by interposing between two successive sheets an anti-adhesion separation sheet, which makes it possible to best use the available manufacturing area and the machine allowing the manufacture of the sheet.

 The invention also relates to a machine allowing the implementation of the aforementioned manufacturing process, said machine being characterized in that it comprises two parallel rails on which rolls one behind the other a finishing frame and a steamroller , said finishing frame comprising at least one heating smoothing rule comprising height adjustment means, that is to say thickness of the layer, and said steamroller comprising height adjustment means and / or adjustment means of the applied load. It is thus possible to manufacture covering sheets of the most appropriate thickness and having been subjected to the most appropriate compression ratio.

The invention will appear more clearly with the aid of the description which follows, made with reference to the appended drawings illustrating by way of example a preferred embodiment. In these drawings
FIG. 1 shows in cross section, schematically and on a large scale, a covering sheet made up according to the invention,
FIG. 2 shows in perspective view with cutaway and on a large scale how the junction between two adjacent strips is advantageously carried out,
- Figure 3 shows schematically in perspective a machine for manufacturing factory sheets of coating.

 - Figure 4 shows in side section the section of the sliding heating rule used on the machine illustrated in Figure 3.

 According to the embodiment illustrated in FIG. 1, a covering sheet 1 essentially consists of a layer 2 formed of waste natural or synthetic rubber, polyurethane or other grains of a similar synthetic material connected and agglomerated together by a suitable binder known in the art, for example of the polyurethane mono or two-component type, polyols, polyether and toluene diisocyanate for example, this layer 2 having towards its lower face 2a a frame formed of crossed films 3, 4 in lattice or mesh embedded in layer 2. In the example illustrated in FIG. 1, the reinforcement is made up of orthogonal crossed wires welded at their junction points. This fine mesh trellis can be made up of crossed glass fibers coated with PVC or synthetic fibers of equivalent mechanical quality, giving the sheet good mechanical resistance, in particular to elongation in all directions. The meshes of the trellis preferably have dimensions slightly greater than those of the grains which constitute the layer. The dimensions of the meshes will advantageously be between 3 and 10 millimeters approximately for coatings with a thickness of the order of 3 to 15 millimeters for example.

 To constitute thick coatings, that is to say of thickness greater than approximately 8 millimeters, the layer of the coating will advantageously be made up of two superimposed thicknesses 5, 6 as illustrated in FIG. 2. The lower layer 5 will comprise at its part lower reinforcement 7 consisting of crossed wires with passage above and below in the example illustrated in FIG. 2 of the weft 8 and warp 9 wires of the reinforcement 7.

 The two layers 5, 6 are interconnected in any suitable manner, for example by a binder, the layer 6 can be deposited on the layer 5 before complete polymerization of the latter. The lower layer 5 may consist of rubber waste (used tires) of black color, while the upper layer 6 will be of better quality and of the appropriate color, for example green or red. If the coating is thick, and if we want to give very good mechanical resistance to the coatings, we can between layers 5 and 6 interpose another frame (not shown) which will be embedded between the two layers and secured to them.

 As will be explained below, advantageously the long ones are produced according to the invention which are unrolled in situ and juxtaposed to form the coating of the desired surface.

 At the junction of two juxtaposed strips, so as to avoid weakness of the coating resulting from the interruption of the underlying frame 7, advantageously, as illustrated in FIG. 2, a strip 10 of armature of nature is placed. similar to that of the frames 7 and which may have a width of a few centimeters for example. On this strip laid even on the underlying support (cellular concrete, floor or asphalt for example), we just stick as well as on the underlying support the juxtaposed strips, the reinforcing strip 10 restoring the resistance of the carpet of the covering at the junction point.

 In order to ensure a perfect junction on the surface of the strips and to avoid differences in quality, in particular of rebound if it is a question of constituting tennis courts, the contiguous edges of two strips are hollowed out or cut in size by forming a groove 11 for example by means of a device known for resculpting used tires. The groove 11 can have a depth for example of 4 to 5 millimeters and a width of about 10 millimeters. In this groove, a coating is poured which infiltrates in the lower part between the two strips and waterproofs the junction. Then, we fill the throat with a product (mixture of elastic grains and binder) of quality similar to that of the coating layer 6 and then we proceed to the flattening of this junction 12 for example by means of an iron, which provides perfect continuity of the coating at the junction of two strips - and very good cohesion of the diaper.

 In the case where it is desired to obtain a composite sheet of the type illustrated in FIG. 2 which is impermeable, use is made to ensure the junction of the two layers 5, 6 with a sealant-pore binder which infiltrates into the lower layer 5 and ensures waterproofing the sheet. The upper layer 6 remains permeable and protects the lower layer by its thickness against the phenomena of punching, especially for sports fields on which spiked shoes can be used.

 Will now be described with reference to Figures 3 and 4, a method and a machine preferably used according to the invention for the manufacture of the composite layers described above.

 In order to overcome meteorological constraints and also obtain better quality coatings and at better prices, the above-mentioned coatings are manufactured flat in the factory on manufacturing areas constituted by perfectly flat raceways. which may for example be 100 meters in length and 2.40 or 3 meters in width.

 On each side of the raceway 13, constituting the surface for manufacturing the covering, are arranged two rails 14, 15 on which rolls one behind the other a finishing frame 16 and a steamroller 17.

 During the manufacture of the coating, the finishing frame 16 is driven forward in the direction of the arrow 18 by an electric motor 19 for example driving a shaft 20 driving a toothed pinion 21 rolling on each side of the path 13 on racks formed on the rails 14, 15. On the frame 16, is fixed in front of it a rule 22 serving to equalize the height of the rough coating (mixture of elastic grains and binder) poured as the advancement of the machine in front of the frame 16. The height of this rule is adjustable on the frame 16 allowing the thickness of the formed layer to be adjusted.

 A little behind the fixed rule 22, a smoothing heating rule 23 is formed, the section of which more clearly matched in FIG. 4. This rule comprises means shown diagrammatically at 24 of micrometric height adjustment. In addition, it includes its own drive means such as an electric motor 25 allowing its movement to move from left to right inside the circulation path 13.

This rule further comprises (not shown) internal circulation channels allowing it to be heated, for example by oil circulating in communication with a tank 26 maintained at the appropriate desired temperature.

 As illustrated in FIG. 4, the leading edge of the rule 23 is slightly inclined, rising for example by an angle equal to 50 relative to the horizontal plane of formation of the sheet in the direction of advancement of the frame. . Thus, a good smoothing effect is obtained and a first compression of the sheet after forming behind the heating rule.

 Behind the finishing frame advances the compression roller 17 which, like the frame 16, includes means 27 making it possible to adjust its height above the raceway.

 At 28, the various electrical controls of the machine are shown diagrammatically.

 We will now describe the use of the machine for the implementation of the method of manufacturing a coating according to the invention.

 The raceway 13 comprises a foundation 29 and on this foundation 29 a layer as even as possible, for example concreted. On this concrete layer 30, first of all, for example, is produced in two successive passes an equalizing coating using the machine, that is to say by applying a reinforcement to the bottom 30 and then the mixture of elastic grains and binder to form a first layer then on this first layer a second layer constituted in the same way, and in the manner which will be described in more detail below. Thus, there is available on the raceway 13 a surface 32 which is plane but also elastic constituting an excellent support for receiving the coating layer to be formed in the factory. it therefore appears that the layers 31, 32 are "lost" layers remaining permanently on the path 13.

 On the surface 32, a sheet 33 of a nonwoven geotextile is applied, for example made of polypropylene and polyester fiber which will prevent any adhesion to the layer 32 of the covering which will be formed.

 On the geotextile 33, the basic reinforcement of the sheet is unwound, after which a first thickness of the covering layer is formed by pouring in front of the finishing frame 16 the appropriate quantities of pulverulent elastic grains and binder after having adjusted at a suitable thickness, the height of the finishing frame 16. Rule 22 ensures a first regular spreading of the product, while the heating smoothing rule animated with a back and forth movement relative to the frame which advances slowly 16 ensures good polymerization and a first compression of the coating layer formed. Behind the finishing frame 16, and at a certain distance, follows the steamroller 17, the height of which is adjusted above the rails 14, 15 and the weight so that it provides compression of determined intensity and size. excellent results are obtained by making three successive compressions of 10% of the thickness of the coating.

 In this way, an unconstrained coating is obtained having excellent qualities of elasticity and tensile strength in all directions, the grains which constitute the coating not being subject to creep or to move.

 As described above, it is possible to form a second layer on a first coating layer, for example to form a composite coating of the type illustrated in FIG. 2. In this case, the lower coating layer 5 is advantageously formed from black waste of second quality, the upper layer 6 being formed of the noble coating of red, green or other suitable color. The connection between the two layers can be obtained automatically during the manufacture of this second layer on the first. If we want to obtain a reinforcement of the multi-layer sheet, we can put a new reinforcement beforehand. If we want to get waterproofing of the multi-layer sheet, we spread on the sheet 5 formed a sealant pore which will seal the interstices and will make the whole waterproof.

 When the machine has reached the end of the runway, the upper surface of the coating that has just been formed will be used as the casting surface for a new sheet with the interposition, obviously, of a non-stick geotextile sheet. We will proceed as described above, starting in the other direction, the finishing frame obviously preceding the steamroller. We can for this purpose use two rollers, one on each side of the frame, the roller being disposed in front of the frame not participating in the operation.

 The coatings designed and manufactured according to the invention have numerous advantages over known coatings. Thus in particular, it is possible to form thinner coatings than according to the prior art and which however have superior strength qualities.

The installation of coverings is also greatly facilitated.

It is possible by assembling strips of different colors to obtain the desired delimitations colored in the mass, of the coated areas.

 Coatings can be used to form play and sports areas, but also terrace coverings, soundproofing of partitions, etc.

 Of course, the invention is in no way limited to the illustrated and described embodiments which have been given only by way of example, the invention comprising all the technical equivalents of the means described as well as their combinations if these These are made according to his spirit and implemented in the context of the claims which follow.

Claims (16)

 1. Coating in the form of a compressible elastic sheet which can be rolled out on site based on waste of natural or synthetic rubber, polyurethane or other grains of a similar synthetic material connected and agglomerated with one another by a suitable binder of the mono or polyurethane type. bi-component, polyols, polyether and toluene diisocyanate, said coating being characterized in that it is formed on a frame 3, 4, 7 made of tre-illis or mesh embedded in it on its substantially rigid, non-elastic underside, very resistant mechanically.  2. Coating according to claim 1, characterized in that said frame is formed by a mesh with fine mesh of crossed glass fibers coated with PVC or synthetic fiber of equivalent mechanical quality.  3. Coating according to claim 2, characterized in that the meshes of the mesh preferably have dimensions of a few millimeters, advantageously between 3 and 10 millimeters approximately.  4. Coating according to one of the preceding claims, characterized in that it comprises at least two superposed layers 5, 6 formed of the abovementioned agglomerated elastic grains connected together by a pore-binding binder ensuring the waterproofing of the sheet. .  5. Coating according to one of the preceding claims, characterized in that it comprises at least two superposed layers 5, 6 formed of the above-mentioned agglomerated elastic grains incorporating between them a reinforcement of the aforementioned type.  6. A method of laying a coating according to one of the preceding claims on an underlying underlayment such as concrete, floor, bitumen or the like, characterized in that it is unrolled on site and glues them from the coating on and along a reinforcement strip 10 of a nature similar to that of the reinforcement 3, 4, 7 used for said sheet.  7. Method according to claim 6, characterized in that said reinforcing strip 10 has a width of a few centimeters, for example from 10 to 30 centimeters.  8. Method according to claim 6 or claim 7, characterized in that one digs or cuts in surface the contiguous edges of two strips by forming a groove 11 several millimeters wide and deep and then clogging this groove by reconstituting in situ a strip 12 of the same quality as the covering layer ensuring perfect continuity of the covering at the junction of two strips.  9. A method of manufacturing a coating sheet according to one of claims 1 to 5, characterized in that said sheet is formed on a flat manufacturing area 13 in the factory, said area being previously covered with a sheet, by example of a non-stick geotextile 33 based on polypropylene or polyester, on which said reinforcement is placed and over which said elastic sheet of elastic grains agglomerated by a binder and comprising one or more layers is formed.  10. Method according to claim 9, characterized in that the operation is repeated several times by forming several sheets superimposed on the same area by interposing between two successive sheets an anti-adhesion separation sheet such as a geotextile.  11. Method according to claim 9 or claim 10, characterized in that one carries out the laying of a first lost layer 31, 32 on said manufacturing area 13 without intermediate insertion of anti-adhesion sheet.  12. Method according to one of claims 9 to 11, characterized in that one carries out the manufacture of a sheet in at least two successive passes by laying two layers of agglomerated elastic grains and interposed between these layers a waterproof sealer and / or reinforcement.  13. Machine for implementing the method according to one of claims 9 to 12, characterized in that it comprises  two rails 14, 15 on which roll one behind the other a finishing frame 16 and a steamroller 17,  said finishing frame 16 comprising at least one heating smoothing rule 23 comprising means 24 for adjusting the height, that is to say of the thickness of the layer,  - Said steamroller 17 comprising height adjustment means 27- and / or means for adjusting the applied load.  14. Machine according to claim 13, characterized in that said rule 23 has a slightly inclined leading edge going up for example by an angle d of 50 relative to the horizontal plane of formation of the sheet in the direction advancement of the framework.  15. Machine according to claim 13 or claim 14, characterized in that said smoothing heating rule 23 comprises a drive motor 25 controlling its own drive movement relative to said finishing frame 16.  16. Machine according to one of claims 13 to 15, characterized in that in front of the smoothing heating rule 23, is mounted on said finishing frame an equalizing rule 22.