Resilient sole and method for manufacturing same

Abstract

Resilient sole 1 which is attached to a concrete layer ( 2 ) or which is positioned between a concrete layer ( 2 ) and ballast ( 3 ), and which is formed by a layer ( 4 ) of recycled rubber, in the revulcanised state after devulcanisation, and a layer ( 5 ) of structured fibres which is arranged so as to be in contact with the rubber layer, the fibres being partially impregnated in the rubber layer and having a free thickness ( 8 ) of structured fibres, assembly comprising the sole and method for manufacturing same.

1 . A resilient sole, arranged in particular to be attached to a concrete layer or positioned between a concrete layer and a ballast, comprising: a recycled rubber layer, in the revulcanised state after devulcanisation, and a layer of structured fibres, arranged in contact with the rubber layer, said fibres being partially impregnated in said rubber layer and having a free thickness of structured fibres. 
     
     
         2 . The resilient sole according to  claim 1 , wherein the structured fibres have a density of between 150 g/m 2  and 800 g/m 2 . 
     
     
         3 . The resilient sole according to  claim 1 , wherein the fibres are impregnated at a depth of between 0.5 and 2 mm, in the revulcanised state. 
     
     
         4 . The resilient sole according to  claim 1 , wherein said recycled rubber layer in the revulcanised state has a Shore hardness of between 50 and 90, according to the standard measuring model, the durometer. 
     
     
         5 . The resilient sole according to  claim 1 , wherein said fibres are chosen from the group of natural or synthetic materials, like polyester, polypropylene, polystyrene, polyethylene, wool, cotton, hemp, coconut fibres. 
     
     
         6 . The resilient sole according to  claim 1 , wherein said recycled rubber layer comprises the rubber chosen from the group of natural or synthetic materials, like natural polyisoprene, isoprene polymer, polybutadiene, styrene-butadiene copolymer. 
     
     
         7 . The resilient sole according to  claim 1 , wherein said rubber layer has a resistance to traction greater than or equal to 7 MPa. 
     
     
         8 . The resilient sole according to  claim 1 , wherein said rubber layer has an extension to rupture greater than 150%. 
     
     
         9 . An assembly, comprising:
 a concrete layer; and   a resilient sole, comprising a recycled rubber layer, in the revulcanised state after devulcanisation, and a layer of structured fibres, arranged in contact with the rubber layer, said fibres being partially impregnated in said rubber layer and having a free thickness of structured fibres, wherein said structured fibres are further partially impregnated on the free thickness of structured fibres in said concrete layer.   
     
     
         10 . The assembly according to  claim 9 , wherein said fibres are impregnated in the concrete block on a thickness of between 0.3 and 2 mm. 
     
     
         11 . A method for manufacturing a resilient sole comprising:
 devulcanising recycled rubber, including formation of a devulcanised recycled rubber mass,   adding at least one devulcanised recycled rubber additive,   superpositioning a layer of structured fibres and devulcanised recycled rubber, including obtaining of two superposed layers,   hot pressing said two superposed layers at a temperature of between 100 and 180° C. during a predetermined time interval with revulcanisation of the devulcanised recycled rubber and formation of a resilient sole where the structured fibres are at least partially impregnated in said rubber layer during revulcanisation, by forming a revulcanised rubber-fibre interphase.   
     
     
         12 . The method for manufacturing a resilient sole according to  claim 11 , wherein said at least one additive comprises sulphur, or at least one resin, or at least one reaction activator or accelerator, or carbon black. 
     
     
         13 . The method for manufacturing a resilient sole according to  claim 12 , wherein said at least one resin is a resin chosen from the group comprising resins having at least one phenol group, at least one aromatic group, at least one styrene group, and any other resin which could be used with sulphur-vulcanised rubber and their combination. 
     
     
         14 . The method for manufacturing a resilient sole according to  claim 12 , wherein said at least one reaction activator is chosen from the group comprising CBS, stearic acid and zinc oxide. 
     
     
         15 . The method for manufacturing a resilient sole according to  claim 11 , wherein after the addition of at least one abovesaid additive, the devulcanised recycled rubber mass is shaped and in that the layer of structured fibres and the devulcanised, shaped recycled rubber, are superposed so as to form said two layers. 
     
     
         16 . The method for manufacturing a resilient sole according to  claim 11 , wherein during the hot pressing, the structured fibres are totally impregnated in said rubber layer during revulcanisation, the method further comprising superficially brushing the impregnated structured fibres, so as to make these partially free, on a predetermined thickness. 
     
     
         17 . The method for manufacturing a resilient sole according to  claim 11 , wherein the superposition and hot pressing steps are carried out in a mould. 
     
     
         18 . The method for manufacturing a resilient sole according to  claim 11 , wherein said devulcanised recycled rubber has a viscosity less than 70 MU, measured on a Mooney viscometer.