Michelin Recherche Et Technique S.a.

Compagnie Generale Des Etablissements Michelin

Compagnie Generale Des Etablissments Michelin

Jérémy Toussain

Sébastien Rigo

Thibaud Pottier

Emmanuel Custodero

Jacques Gauthier

A method of manufacturing a metal cord with two concentric layers of wires is provided. The cord includes an internal layer of M wires, M having a value from 1 to 4, and an external layer of N wires. The cord is rubberized from within in situ. That is, during manufacture of the cord, the cord is rubberized from inside. According to the method, the internal layer is sheathed with rubber or a rubber compound by passing the internal layer through an extrusion head, and the N wires of the external layer are assembled around the sheathed internal layer to form a two-layer cord rubberized from the inside. The rubber is an unsaturated thermoplastic elastomer that is extruded in a molten state, and preferably is a thermoplastic styrene (TPS) type of thermoplastic elastomer, such as an SBS or an SIS block copolymer, for example.

Method of manufacturing a two-layer metal cord rubberized in situ using an unsaturated thermoplastic elastomer

A metal cord has an M+N construction with two concentric layers. An internal first layer or core includes M wire(s) of diameter d, M having a value from 1 to 4. An external second layer includes N wires of diameter dand is positioned around the core, the N wires being wound in a helix. Between the wires of the two layers are gaps, some or all of which include a filling rubber based on an unsaturated thermoplastic elastomer. The filling rubber may be, for example, based on an SBS or an SIS block copolymer. When used in a molten state, the thermoplastic elastomer presents no problem due to unwanted stickiness if the filling rubber overspills outside the cord after manufacture. The unsaturated and therefore (co)vulcanizable nature of the thermoplastic elastomer makes it compatible with diene rubber matrices used as calendering rubber in metal fabrics intended for reinforcing tires.

Two-layered metal cord rubberized in situ by an unsaturated thermoplastic elastomer

Method of manufacturing a multi-layer metal cord having a plurality of concentric layers of wires, comprising one or more inner layer(s) and an outer layer, of the type 'rubberized in situ. The method includes the following steps: at least one step of sheathing at least one inner layer with the rubber or the rubber composition by passing through at least one extrusion head; and an assembling step in which the wires of the outer layer are assembled around the inner layer adjacent to it, in order to form the multi-layer cord thus rubberized from the inside. The rubber is an unsaturated thermoplastic elastomer extruded in the molten state, preferably a thermoplastic elastomer of the thermoplastic stirene (TPS) elastomer type such as an SBS, SBBS, SIS or SBIS block copolymer for example.

Method for the production of a multi-layer metal cord that is rubberized in situ using an unsaturated thermoplastic elastomer

Method for manufacturing a metal cord with three concentric layers including a first layer of diameter dmade up of M wire(s) of diameter d, around which layer are wound together as a helix at a pitch p, as a second layer, N wires of diameter d, around which are wound as a helix at pitch p, as a third layer, P wires of diameter d. The N wires of the second layer are assembled around the layer to form, at a point called 'assembling point', an intermediate cord called 'core strand' of M+N construction; upstream and/or downstream of the assembling point, the layer and/or the core strand is sheathed with a rubber or rubber composition by passing through at least one extrusion head; then the P wires of the third layer are assembled around the core strand to form a cord of M+N+P construction thus rubberized from the inside.

Method for the production of a three-layer metal cord of the type that is rubberized in situ

Method of manufacturing a metal cord with three concentric layers (C, C, C), of the type rubberized in situ, i.e. incorporating a composition made of rubber in the uncrosslinked state referred to as 'filling rubber', the said cable comprising a first, internal, layer or core (C), around which there are wound together in a helix, at a pitch p, in a second, intermediate, layer (C), N wires of diameter d, N varying from 3 to 12, around which second layer there are wound together as a helix at a pitch p, in a third, outer, layer (C), P wires of diameter d, P varying from 8 to 20, the said method comprising the following steps: a first sheathing step in which the core (C) is sheathed with the filling rubber; a first assembling step by twisting the N wires of the second layer (C) around the core (C) thus sheathed in order to form, at a point named the 'assembling point', an intermediate cord named &#x201c;core strand&#x201d; (C+C); downstream of the said assembling point, a second sheathing step in which the core strand (C+C) is sheathed with the filling rubber; a second assembling step in which the P wires of the third layer (C) are twisted around the core strand (C+C) thus sheathed; a final twist-balancing step.

Method and device for producing a three-layer cord

Method of manufacturing a metal cord with three concentric layers (C, C, C), of the type rubberized in situ, i.e. during its manufacture comprising a first, internal, layer or core (C), around which there are wound together in a helix, at a pitch p, in a second, intermediate, layer (C), N wires of diameter d, N varying from 3 to 12, around which second layer there are wound together as a helix at a pitch p, in a third, outer, layer (C), P wires of diameter d, P varying from 8 to 20, the said method comprising the following steps: a sheathing step in which the core (C) is sheathed with a rubber composition named 'filling rubber', in the uncrosslinked state; an assembling step by twisting the N wires of the second layer (C) around the core (C) thus sheathed in order to form, at a point named the 'assembling point', an intermediate cord named a &#x201c;core strand&#x201d; (C+C); an assembling step in which the P wires of the third layer (C) are twisted around the core strand (C+C); a final twist-balancing step.

A device and method for manufacturing a metal cord with three concentric layers, rubberized in situ, of M+N+P construction, wherein the method comprises the following steps which are performed in line: an assembling step by twisting N wires around a first layer to form, at a point named the 'assembling point', an intermediate cord named a 'core strand' of M+N construction; downstream of the assembling point, a sheathing step in which the M+N core strand is sheathed with a rubber composition named &#x201c;filling rubber&#x201d; in the uncrosslinked state, an assembling step in which P wires of the first layer are twisted around the core strand thus sheathed, and a final twist-balancing step.

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Clermont-Ferrand, France

Jérémy Toussain