FR2763880A1 - Resilient wall or floor covering composite production from e.g. waste rubber granules - Google Patents

Abstract

The novel continuous process makes special coverings for floors or walls. A layer (2) of polymer binder mixed with elastomeric particles or granules is deposited on a base material carrying it along. The layer is continuously compressed and hardened, passing it through an oven (13). Novel features include the substrate, which is permeable to steam injected through it and the layer as they pass over, prior to or during compression of the elastomeric layer. Also claimed are: a plant to carry out the process; a synthetic grass covering, including blades of synthetic grass; a flexible underlayer for sports areas; and a band of covering material for walls or floors. This has improved sound deadening properties and is made with woven or non-woven fabric layers.

Description

The present invention relates to the continuous manufacture of a coating which is in the form of a strip comprising at least one layer formed from a mixture of at least one polymeric binder and particles or aggregates of elastomers, and more particularly, but not exclusively, of crushed rubber waste. The invention more particularly finds its application in the low-cost manufacture of floor or wall coverings having improved phonic properties, from a simple textile fabric, or also in the manufacture of flexibility underlay for sports ground or synthetic turf with integrated flexibility underlay.

We have already proposed in the European patent application
EP-AO 135 595 a process for continuously manufacturing a floor covering from a pasty or semi-pasty mixture consisting of at least one binder and particles or aggregates of recovery products, and in particular rubber waste. According to the method described, the above-mentioned mixture is deposited in its pasty form on the surface of the belt of a conveyor. The mixture is distributed over the entire width of the conveyor belt, is compressed by means of a calendering roller immediately after being deposited, and continuously passes through an oven being driven by the belt conveyor, so as to harden the mixture layer by polymerization of the binder. In a particular variant of embodiment, it is taught to deposit continuously on the mixing layer, upstream of the inlet of the oven, a textile covering layer, which will constitute the visible upper face of the floor covering, the mixing layer after hardening constituting a flexibility sublayer. The use of particles or aggregates of recovery product to produce the undercoat advantageously makes it possible to produce a floor covering at low cost which has very good properties of flexibility and shock absorption.

 In the aforementioned process, the hardening of the mixture layer by polymerization of the binder being obtained only by the heating action in the oven, the time of stay of the mixture in the oven must be long enough for the binder to reach during its passage through the oven a sufficient degree of polymerization. With this process, it is therefore limited in production rate, unless of course increasing the length of the oven to prolong the action of heating, which is detrimental in terms of cost. In addition, when the method of document EP-A-0135595 is used to produce a floor covering with textile covering layer, the mixture constituting the underlay between the conveyor belt is sandwiched and the textile covering layer. As a result, the heating of the mixture constituting the sublayer is less effective, which is detrimental to the hardening of the sublayer, by polymerization of the binder, and consequently obliges to reduce the production rate.

 The aim of the present invention is to propose a process for the continuous production of an elastomeric coating which overcomes the aforementioned drawbacks of the process described in European patent application EP-A-0435595, in that it allows comparatively to increase the production rate while obtaining a good quality elastomeric coating.

 This object is achieved by the process of the invention which, in a manner known by European patent application EP-AO 135 595, consists in depositing on a drive support a layer called an elastomer layer, of a mixture of at least one polymer binder and particles or aggregates of elastomers, to continuously compress the elastomer layer, and to harden the compressed elastomer layer by ia scrolling in an oven.

 Characteristically according to the invention, the drive support is permeable to water vapor and water vapor is injected through the elastomer layer in movement, before or simultaneously with the compression of the elastomer layer . The injection of water vapor according to the invention advantageously makes it possible to humidify and heat the elastomeric layer and to trigger the polymerization of the binder before the passage of this layer in the oven, which allows faster hardening. of the elastomeric layer. In addition, the compression combined with the injection of water vapor makes it possible to obtain better stabilization of the elastomer layer in the form which is given to it by compression.

 Advantageously, the method of the invention can be implemented to produce a composite coating by superposition of at least one textile strip and an elastomer layer before the operations of injecting pressurized steam, compression and of heating. In a preferred embodiment, the mixture layer is deposited on the surface of the textile strip which acts as a drive support and which is driven while being held taut by its selvedges transversely to its direction of advance.

 Another subject of the invention is an installation For the implementation of the method of the invention, which in a manner known by European patent application EP-A-0.135.595 comprises a drive support, a mixing plant and dispenser which contains a mixture of at least one polymeric binder and particles or aggregates of elastomers and which is arranged above the drive support, at least one calendering cylinder which is rotatably mounted above and near of the drive support, and a baking oven traversed by the drive support. Typically according to the invention, the drive support is permeable to water vapor and the installation comprises, near the calendering cylinder, at least one nozzle for injecting pressurized water vapor, which is arranged near the drive support and which is oriented transversely to the drive support.

 Other characteristics and advantages of the invention will appear more clearly on reading the description which will now be made of an installation and its implementation for the manufacture of a textile covering with an integrated elastomer layer, which description is given by way of nonlimiting example and with reference to the appended drawing in which - FIG. 1 is a schematic view of a preferred variant embodiment of an installation according to the invention, - FIG. 2 is a view of above the installation of FIG. 1, FIG. 3 is a schematic sectional view of the surface of a sports field on which strips of synthetic grass have been laid with an underlay of integrated flexibility, produced by of the installation of FIGS. 1 and 2, and FIG. 4 illustrates another example of the implementation of a flexibility underlay for a sports field produced by means of the installation of FIG. 1.

 The installation of FIG. 1 makes it possible to continuously manufacture a composite coating which is in the form of a textile strip and an elastomer layer 2, with an insulation and / or flexibility function.

The elastomer layer 2 is produced in a manner known per se in a mixing and distribution center 3, from a complex composed of aggregates or particles of elastomers (for example natural rubber / NR butadiene styrene copolymer / SBR, polybutadiene / BR, copolymer of ethylene and propylene / EPM, terpolymers of ethylene, propylene and a dith / EPDM, ...), and one or more polymeric binders allowing after aggregation to agglomerate the aggregates or elastomer particles. Preferably, the particles or aggregates of elastomer will come from the grinding of recovered rubber waste. The mixture could however also contain particles or aggregates of new rubber, as well as particles or aggregates of new or used cork. The binder used will be, for example, polyurethane. At the outlet of the mixing plant 3, a pasty or semi-pasty mixture 4 is obtained. The advantage of the aforementioned complex is that it makes it possible to produce a layer of flexibility and / or insulation at very low cost, which allows to produce coatings having a significant thickness of elastomer layer at a lower cost.

 In the installation of FIG. 1, the textile strip 1 is initially wound on a rotary mandrel 5 for its feeding, and is unrolled continuously at a constant linear speed up to a rotary storage mandrel 6 disposed at the outlet of the installation. The scrolling of the textile strip 1 in the installation of FIG. 1 is carried out in such a way that the face 1a of this strip 1, referred to below as the front side, is oriented downwards. At the outlet of the food mandrel 5, the textile strip 1 passes over a coating table 7 at the level of which the mixture 4 intended to constitute the layer 2 is deposited on the reverse side 1 b of the textile strip 1.

 If one refers to FIG. 2, the deposition of the mixture 4 is not carried out over the entire width L of the textile strip 1, but is carried out over a limited width l slightly less than the width L so that the two selves îc of the textile strip 1 are not covered by the mixture. To this end, the installation comprises, at the level of the coating table 7, two vertical walls 8a disposed above and centered relative to the textile strip 1 so as to form a feed corridor for the mixture 4.

 At the feed corridor formed by the walls 8a is mounted a double vibrating bar 9 making it possible to distribute the mixture 4 evenly over the entire width! on the reverse side 1 b of the textile strip 1.

 At the outlet of the coating table 7, the composite coating formed by the textile strip 1 and the elastomer layer 2 is taken up for its drive by a row of pins 10. This type of drive device is already known in the textile field to thermofix a textile support after coating, at a predetermined width. Referring to FIG. 2, the studded train 10 comprises in known manner two endless chains 11 parallel and positively driven in rotation at the same speed. Each endless chain is fitted over its entire length with a succession of pins 1 2.

The spacing d between the two endless chains 1 1 is adjustable. This spacing is adjusted so that the pins 12 of each endless chain 1 1 respectively pass through the selvedges 1 c of the covering textile layer 1. The two endless chains 1 1 thus make it possible to drive and support the 'stretched state in the direction of its width, that is to say transversely to its direction of advance, the coating via the edges 1c of the textile strip 1. If one refers to Figure 1 , the covering is supported by the row of pins 10 between the coating table 7 and the oven 13 and during the entire transport phase inside an oven 13, which has the function of heating the layer 2 in order to harden it by polymerization of the binder contained in the mixture 4.

 With the aim of compressing the coating layer 2 to a predetermined thickness, the installation of FIG. 1 further comprises a first calendering cylinder 14 engraved with grooves, which is placed above the coating table 7, and the axis 14a of which is preferably adjustable in height with respect to the coating table 7. A first continuous compression of the layer 2 of the coating is thus produced between the cylinder 14 and the coating table 7. This first cylinder calendering 14 is followed by a second calendering cylinder 14 ′ whose axis 14 ′ a is also adjustable in height relative to the coating table 7. In the preferred alternative embodiment of FIG. 1, the installation comprises also three successive pairs of calendering cylinders (15a, 15b), (16a, 16b), and (17a, 17b), which are mounted just upstream from the inlet of the furnace 13. The two calendering cylinders of the same pair are mounted on each side and on the other re of the coating, and thus make it possible to carry out a complementary compression of the layer 2. Advantageously, the distances between the axes e1, e2 and e3 of the three successive pairs of calendering rolls will be adjustable, and adjusted to decreasing values so as to achieve progressive, increasingly tight compression of the layer 2 before entering the furnace 13.

According to the invention, the installation of FIG. 1 comprises a first injection nozzle 18a, which is connected to a central unit 21 producing steam under pressure, and which is arranged at the level of the first two cylinders of calendering 14 and 14 '. This nozzle has the function of injecting pressurized water vapor through the permeable coating, during the compression of the layer 2 by the calendering cylinders 14 and 14 '. Referring to FIG. 2, the nozzle 18 has an outlet orifice 18a, which in the example illustrated is of substantially rectangular shape, and which extends substantially over the entire width l of the layer 2. This orifice 18a of the nozzle 18 arrives in the immediate vicinity of the front face of the coating 1. For this purpose, a light (not shown) is provided in the coating table 7, in order to allow the passage of the nozzle 1 8 and to bring the outlet orifice 18a of this nozzle as close as possible to the face face la of the textile strip 1 in movement. In the particular example illustrated, the orifice 18 of the nozzle 18 is situated substantially between the two calendering cylinders 14 and 14 '. However, in another variant, the nozzle 18 could also be placed immediately upstream of the first cylinder 14 or even immediately downstream of the second cylinder 14 ', knowing that in general it is sufficient for this nozzle to be disposed near these two calendering cylinders 14,14 ', so that the steam injection can act simultaneously with the compression of the mixture by the calendering cylinders 14,14'
The injection of water vapor advantageously makes it possible to initiate the polymerization reaction of the binder (s) contained in the mixture 4 forming the layer 2. In addition, by compressing the layer 2 simultaneously with the injection of steam, a better result is obtained. stabilization in the form of layer 2 after compression.

 In the particular example of FIG. 1,1, the installation also comprises two complementary injection nozzles 19 and 20 which are also connected to the steam generator 21. The injection nozzle 19 is placed substantially halfway between the second calendering cylinder 14 'and the first pair of calendering cylinders 1 Sa, 1 5b.

The injection nozzle 20 is positioned between the first two pairs of calendering cylinders (15ê, 15b) and (16a, 16b). Similar to the nozzle 18, each nozzle 19 and 20 is positioned below and near the right side of the textile strip 1 of the covering and has the function of spraying water vapor through the layer 2 of the coating.

 It is up to the person skilled in the art to adjust the flow rate of water vapor supplying the nozzles 18, 19 and 20 as a function of the geometry of the nozzles, their distance from the coating, the type of coating, and in particular the layer 2 thickness. In the example illustrated, each nozzle 18, 19 or 20 is supplied with steam via a regulating valve 22. In practice, the flow of water vapor supplying a given nozzle 18,19 is adjusted manually. or 20 by means of the associated control valve, and increasing the flow rate until it is visually observed that the water vapor coming from the nozzle passes through the coating.

 The main advantage of the process of the invention is that it allows the continuous production at high speed of a coating whose elastomer layer 2 is perfectly stabilized in shape. In a specific embodiment, the production rate of the installation of FIG. 1 was of the order of 2 m / minute, the length of the oven 1 3 was worth 8 m, and the temperature of the oven 13 was between 150 ° C. and 160 C.

 As an indication, to obtain a thin layer 2 (3 to 6 mm), small aggregates (0.6 to 1.8 mm) are used with 1 1 to 1 2% by weight of polyurethane. For larger thicknesses (7 to 12mm), aggregates of 1.8 to 4mm are used with 8 to 10% by weight of polyurethane.

 The use of a pin oar 10 also has several advantages. First of all, the textile strip 1 being maintained in the stretched state in the direction of its width, any risk of retraction of this textile strip is avoided during the injection of water vapor, and during its passage through the oven 13, which makes it possible to obtain a coating having very good dimensional stability. In addition, compared to a solution in which the textile strip 1 would be transported by being placed on the surface of a conveyor, a more efficient and more homogeneous heating of the coating is obtained throughout its volume. Finally, it is avoided that the textile strip 1 is damaged or degraded during manufacture. It thus advantageously becomes possible to use as a textile strip a covering textile fabric whose face face 1a is fragile, which is the case for example for wall coverings.

 At the outlet of the oven 13 and before the winding of the coating obtained on the outlet mandrel 6, the selvages îc of the textile strip 1 which are not covered by the elastomer layer 2 can advantageously be removed automatically by means of saws with ribbon (not shown) arranged at the outlet of the two chains 1 1 of the spiked train 10.

 A first application of the method of the invention is the production of wall coverings having improved sound insulation properties, from a textile support which will be chosen for its aesthetic qualities (printed pattern, particular structure), or for reasons techniques for example a glass cloth to obtain a significant dimensional stability or even a fireproof cloth to obtain a fire resistant coating. It is also conceivable to produce wall coverings having an elastomeric layer of sufficiently large thickness to use this covering by sticking it on a flocking of asbestos so as to constitute an insulating formwork.

 A second application of the method of the invention is the production of an insulating floor mat using as textile band 1 a simple textile fabric or a nonwoven sufficiently thick to itself possess good sound insulation qualities which are added to those obtained by the addition of the elastomer layer. It is, for example, a needle punch with a thickness of between 1.5mm and 5mm, and reinforced with a reinforcing textile fabric (glass or polyester fabric). Such an insulating floor mat can for example be placed between a cement slab on which it will be glued and a covering requiring soundproofing (parquet, tiles, etc.) which will be glued to the insulating mat.

 A third application of the process of the invention is the continuous production of synthetic grass strips 23 for sports grounds, with an elastomer layer 2 of integrated flexibility (FIG. 3). For this purpose, a strip of synthetic turf consisting of a textile support 25 is used as the textile strip 1, on which are strands of synthetic grass 24 formed in known manner forming the face 1a of the textile strip 1. The strips of synthetic grass 23 obtained according to the method of the invention can advantageously be laid on the surface of a sports field as illustrated in FIG. 3, being assembled with respect to each other at their longitudinal edges by means of joining strips 27. The joints 26 between strips will advantageously be filled with glue.

 In this application, the function of layer 2 is to give the synthetic turf sufficient flexibility to absorb shocks.

Another function of the suppleness layer 2 is to ballast the strips of synthetic grass 23, which makes it possible to very significantly reduce the supply of sand which is usually practiced on the face of the side of the strips of synthetic grass to ballast them. . With the synthetic grass strips of the invention, this addition of sand may advantageously be just sufficient to obtain satisfactory penetration of the studs of sports shoes, which makes it possible not only to obtain savings in sand, but also to give the grass a superior aesthetic, avoiding that the sand brought is visible.

 In a fourth application, by means of the installation of FIG. 1, a composite flexible sublayer 28 is produced which comprises an upper elastomer layer 28a and a lower protective textile layer 28b, and which is intended to be interposed for example between a synthetic grass 29 and the irregular surface 30 of the ground, the textile layer 28b coming into contact with the ground. In this application, the textile layer 28b protects the elastomeric layer 28a from irregularities in the ground and in particular pebbles and advantageously makes it possible to extend the life of the elastomeric layer.

In this application, use will preferably be made for the textile layer 28b of a nonwoven or a fabric having a grammage of between 100 and 140 g / m2, and made of a fiber which withstands the temperature of steam and the oven (150 / 160 "C), which gives the final product good dimensional stability. For example, polyester or glass fibers will be used.

 In an alternative embodiment, the method of the invention can also be used to continuously manufacture coatings comprising an elastomer layer 2 sandwiched between two textile strips 1 and 1 '. For this purpose, if one refers to FIG. 1, a textile strip 1 'is successively deposited continuously on the elastomer layer 2, then the textile strip 1 / elastomer layer 2 / textile strip 1' is compressed . In the particular example illustrated, the textile strip 1 'is deposited between the two calendering cylinders 14 and 14'.

In another variant, it can be deposited upstream of the first calendering cylinder 14, or even upstream of the double vibrating bar 9. The textile strip 1 ′ will preferably be a reinforcing textile strip chosen so as to increase the dimensional stability of the product. In an exemplary embodiment, given as a guide, it was a woven grid of high tenacity polyester or glass fibers, having a basis weight between 11 Og / m2 and 1 40g / m2 and a warp density and in a 3-wire weft of 11000 dtex / cm and preferably having undergone an SBR-Latex impregnation.

 The invention is not limited to the production of a textile strip 1 / elastomer layer 2 composite coating, but can also be applied to the production of a strip consisting exclusively of a single elastomer layer 2. In this case, the mixture constituting the elastomer layer 2 will for example be deposited on the surface of a conveyor, the conveyor belt of which will be chosen to be permeable to water vapor. Finally, in the context of the invention, it is also possible to manufacture a textile / elastomeric composite coating by depositing the mixture 4 directly on the surface of a conveyor, the conveyor belt of which is permeable to water vapor and depositing the textile band 1 on the elastomer layer 2, the elastomer layer in this case being sandwiched between the conveyor belt and the textile band 1.

Claims (14)

1. Process for the continuous production of a coating according to which an elastomer layer (2) of a mixture (4) of at least one polymeric binder and of particles or aggregates of elastomers is deposited on a drive support, the elastomer layer (2) is continuously compressed and the compressed elastomer layer (2) is hardened by passing it through an oven (13), characterized in that the drive support is permeable to water vapor and what water vapor is injected through the elastomeric layer (2) while traveling before or simultaneously with the compression of the elastomeric layer (2). 2. Method according to claim 1 characterized in that the compression of the elastomeric layer (2) is carried out immediately after injection of water vapor. 3. Method according to one of claims 1 or 2 characterized in that the injection of water vapor is carried out substantially over the entire width (I) of the elastomeric layer (2). 4. Method according to one of claims 1 to 3 characterized in that a composite coating is produced by superimposing at least one textile strip (1) and an elastomer layer (2) before the successive operations of steam injection of pressurized, compression and heating water. 5. Method according to claim 4 characterized in that the elastomeric layer (2) is deposited on the textile strip (1) which acts as a driving support and which is driven while being held taut by its selvedges (1 c) transversely to its direction of advancement. 6. Method according to claim 5 characterized in that the mixture is deposited (4) on the textile strip (1) so that the edges (1c) of the textile strip are devoid of mixture. 7. Method according to claim 5 characterized in that a continuous textile strip (1 ') is deposited on the elastomer layer (2), and the textile strip (1) / elastomer layer (2) / strip is compressed textile (1 '). 8. Installation for the implementation of the process referred to in one of claims 1 to 7, comprising a drive support, a mixing and distribution center (3) which contains a mixture of at least one polymeric binder and of particles or aggregates of elastomers and which is arranged above the drive support, at least one calendering cylinder which is rotatably mounted above and near the drive support, and a baking oven (13) , characterized in that the drive support is permeable to water vapor and in that the installation further comprises, near the calendering cylinder, at least one nozzle for injecting pressurized steam, which is arranged near the drive support and which is oriented transversely to the drive support. 9. Installation according to claim 8 for the manufacture of a composite coating comprising a textile strip (1) and an elastomer layer (2) characterized in that the drive support consists of the textile strip (1) which is driven by a reamer type driving device with pins (10) designed to support in the stretched state the textile strip (1) by means of its two selvedges (1c). 10. Installation according to claim 9 characterized in that it comprises a coating table (7) at which the mixture (4) is deposited on the textile strip (1), and two successive calendering cylinders (14, 14 ') arranged above the coating table (7) and in that a first injection nozzle (18) is provided near the two calendering cylinders (14,14'). 11. Installation according to claim 10 characterized in that it comprises, upstream of the oven (13), one or more successive pairs of calendering cylinders (15a - 15b; 16a - 16b; 17a - 170, at least one second nozzle d injection (19) of pressurized steam between the two first calendering cylinders (14, 14 ') and the first pair (15a - 15b) of calendering cylinders and at least one third injection nozzle (20) pressurized steam near the pairs of calendering cylinders (15a, 15b; 16a, 16b). 12. Strip of synthetic turf with integrated flexible sublayer obtained by implementing the method referred to in one of claims 4 to 6, with as textile strip (1) a strip of synthetic grass (23) consisting of a textile support (25) on which are fixed blades of synthetic grass (24) forming the front face (la). 13. Flexibility underlayer (28) for a sports field obtained by implementing the method referred to in one of claims 4 to 6 and comprising an elastomer layer (28a) and a protective textile layer (28b). 14. Wall or floor covering strip having improved sound insulation properties, and obtained by implementing the process referred to in one of claims 4 to 6 with a textile strip or a textile strip as textile strip (1). non-woven, itself having good sound insulation qualities, which are added to those of the mixing underlay.