The invention relates to a multiple extrusion press head for producing tread profiles of tyres, comprising: a base body (12) having a first supply opening (22) for connecting a first extruder, a second supply opening (24) for connecting a second extruder, a third supply opening (26) for connecting a third extruder, and a fourth supply opening for connecting a fourth extruder; a first head part (14) which is mounted such that it can swivel in relation to the base body, and which has a receiving means (32) that is open in the direction of the base body (12); a second head part that is mounted such that it can swivel in relation to the base body (12); at least one flow channel insert (18, 20) that is mounted such that it can swivel in relation to the base body (12), wherein the first head part (14) and the second head part (16) can be brought into a closed state, in which the head parts (14, 16) are connected to one another in a pressure-tight manner, and a first flow channel (34), a second flow channel (36), a third flow channel (38) and a fourth flow channel (40) are formed in the multiple extrusion press head (10), wherein every flow channel is connected to a supply opening. According to the invention, the base body (12) has a fifth supply opening (30) for connecting a fifth extruder, and the multiple extrusion press head (10) has a second flow channel insert (20), which, independently of the first flow channel insert (18), is mounted such that it can swivel in relation to the base body (12), and borders a fifth flow channel (42) that is connected to the fifth supply opening (30).

The invention relates to a multiple extrusion press head for producing tread profiles of tyres, comprising: a base body (12) having a first supply opening (22) for connecting a first extruder, a second supply opening (24) for connecting a second extruder, a third supply opening (26) for connecting a third extruder, and a fourth supply opening for connecting a fourth extruder; a first head part (14) which is mounted such that it can swivel in relation to the base body, and which has a receiving means (32) that is open in the direction of the base body (12); a second head part that is mounted such that it can swivel in relation to the base body (12); at least one flow channel insert (18, 20) that is mounted such that it can swivel in relation to the base body (12), wherein the first head part (14) and the second head part (16) can be brought into a closed state, in which the head parts (14, 16) are connected to one another in a pressure-tight manner, and a first flow channel (34), a second flow channel (36), a third flow channel (38) and a fourth flow channel (40) are formed in the multiple extrusion press head (10), wherein every flow channel is connected to a supply opening. According to the invention, the base body (12) has a fifth supply opening (30) for connecting a fifth extruder, and the multiple extrusion press head (10) has a second flow channel insert (20), which, independently of the first flow channel insert (18), is mounted such that it can swivel in relation to the base body (12), and borders a fifth flow channel (42) that is connected to the fifth supply opening (30).

Aspects of the present invention relate to methods for characterizing a multi-layered tire tread. In one example, a method comprises providing a first rubber composition having a first refractive index and providing a second rubber composition having a second refractive index. The method further comprises determining a difference between the first refractive index and the second refractive index and comparing the difference to a threshold refractive index. In addition, the method comprises adding a refractive index modifier to the first rubber composition and/or second rubber composition in case the comparison provides that the difference is lower than the threshold refractive index, so that the difference is greater than, or equal to, the threshold refractive index.

Aspects of the present invention relate to a tire tread production line and a method for manufacturing a tire tread. The production line comprises a coextruder, a THz sensor and a controller operatively connected to the coextruder and to the THz sensor. The THz sensor is configured to irradiate the multi-layer tire tread extrudate with THz electromagnetic radiation, and receive a response of the multi-layer tire tread extrudate to the THz electromagnetic radiation. The controller is configured to operate the coextruder based on the response of the multi-layer tire tread extrudate to the THz electromagnetic radiation.

A method for forming a composite tread, the method comprising the steps of forming a coextruded strip of a first compound and a second compound, wherein the first compound is a tread compound, and the second compound is formed from a high-wear compound, wherein the tread is formed from winding the coextruded strip onto the tire building drum while varying the ratio of the first compound to the second compound.

A system for the continuous extrusion, molding, and curing of tread rubber is provided. A plurality of discrete mold sectors are arranged adjacent to each other along a longitudinal axis between an in-feed and an out-feed of a mold sector transport mechanism that extends through a heated press. As the mold sectors are continuously advanced along a process direction in steps, rubber material is extruded and placed onto at least one of the mold sectors near the in-feed end such that an elongated strip of rubber material extends over multiple mold sectors along the longitudinal axis. As the strip of rubber material exits the press, the mold sectors are sequentially removed from the rubber material and returned to the in-feed. An extruder outlet positioned near the in-feed can be moved towards or away from the mold sectors to supply rubber material and prevent backflow.

A system for the continuous extrusion, molding, and curing of tread rubber is provided. A plurality of discrete mold sectors are arranged adjacent to each other along a longitudinal axis between an in-feed and an out-feed of a mold sector transport mechanism that extends through a heated press. As the mold sectors are continuously advanced along a process direction in steps, rubber material is extruded and placed onto at least one of the mold sectors near the in-feed end such that an elongated strip of rubber material extends over multiple mold sectors along the longitudinal axis. As the strip of rubber material exits the press, the mold sectors are sequentially removed from the rubber material and returned to the in-feed. An extruder outlet positioned near the in-feed can be moved towards or away from the mold sectors to supply rubber material and prevent backflow.

A system for the continuous extrusion, molding, and curing of tread for tires. An elongated strip of rubber material can be molded and cured shortly after extrusion such that the material retains much of the heat energy of extrusion and does not have to be stored. A plurality of discrete mold assemblies are conveyed adjacent to each other. As the mold assemblies are advanced sequentially, the uncured and unmolded strip of rubber material are extruded and positioned onto the mold assemblies. While the rubber strip advances, individual portions are sequentially molded and cured by passing through a mold press and then a curing press. A plug assembly is used to prevent the backflow of rubber material during the molding and curing.

A system for the continuous extrusion, molding, and curing of tread for tires. An elongated strip of rubber material can be molded and cured shortly after extrusion such that the material retains much of the heat energy of extrusion and does not have to be stored. A plurality of discrete mold assemblies are conveyed adjacent to each other. As the mold assemblies are advanced sequentially, the uncured and unmolded strip of rubber material are extruded and positioned onto the mold assemblies. While the rubber strip advances, individual portions are sequentially molded and cured by passing through a mold press and then a curing press. A plug assembly is used to prevent the backflow of rubber material during the molding and curing.

A tire tread extractor used in the manufacture of treads includes a frame, a first nip roller rotatably associated with the frame, and a second nip roller rotatably associated with the frame. The first and second nip rollers are adapted to engage a tire tread at least partially resident in a mold. A driving mechanism associated with the first and/or second nip rollers operates to impart rotational motion thereto. The frame is configured for longitudinal movement along a substantial portion of a longitudinal length of the mold while maintaining the first and second nip rollers in a spaced relation to the mold.