Pirelli Pneumatici S.p.a.

Pirelli Coordinamento Pneumatici S.p.a.

Antonio Proni

Daniele Balasso

Gianluigi Hotellier

Renato Caretta

Roberto Pessina

Alan Bottomley

Danile Balasso

A method for mixing a compound in a closed-batch mixer includes predetermining a minimum temperature of a mixer body for starting a mixing cycle; predetermining a preheating temperature for a thermal-regulation system of the mixer as a first set point; predetermining a working temperature for the system as a second set point; predetermining a thermal-hysteresis value of the mixer body; predetermining a first temperature of the mixer body for switching the system from the first to the second set point; predetermining a second temperature of the mixer body for switching the system from the second to the first set point; directly measuring mixer-body temperature using continuous, real-time measurement; comparing the mixer-body temperature to the first and second temperatures; and switching the system from the first to the second set point or from the second to the first set point, if required, as a result of the comparison.

Thermally regulated closed mixer

A closed mixer includes a mixing chamber, a pair of rotors, and a pressing ram. The pressing ram is moveable between a resting condition, which allows introduction of material into the mixing chamber, and a working condition. A method of processing polymer-based mixtures and compounds in the closed mixer includes introducing material into the mixing chamber, moving the pressing ram from the resting condition to an upper end-of-stroke position, and moving the pressing ram from the upper end-of-stroke position to a lower end-of-stroke position. A position-time profile of the pressing ram is controlled during moving the pressing ram from the upper end-of-stroke position to the lower end-of-stroke position.

Closed mixer working process with stroke-control ram

A process for manufacturing a composition of matter from components includes combining the components to produce a blend and combining the blend with a crosslinking system to produce the composition. The components include a polymer base, a silica reinforcing filler, a silica-binding agent, and further product and process additives. Combining the components is carried out in a closed mixer comprising a piston and a pair of rotors. While combining the components, values of at least two indirect parameters and at least two direct parameters are measured at least every two minutes. The at least two indirect parameters comprise blend temperature and power absorbed by the rotors. The at least two direct parameters comprise pressure exerted by the piston and rotations of the rotors. The at least two indirect parameters are maintained within respective ranges of predetermined values by controlling one or more of the at least two direct parameters.

Process for manufacturing a tire compound

A method for processing a rubber mixture or compound for tire manufacturing includes the steps of determining variation tolerances with respect to reference values for process parameters, detecting values of the process parameters, comparing detected values of the process parameters with the reference values and the variation tolerances, attributing an evaluation to a semi-finished product depending on compliance or noncompliance of the detected values with the reference values and the variation tolerances, classifying the semi-finished product on a basis of the attributed evaluation, and establishing successive steps for processing the semi-finished product depending on the classification of the semi-finished product. The processing includes at least a mixing cycle and an extrusion cycle for obtaining the semi-finished product. The cycles are controlled by the process parameters detected during execution of the cycles.

Processing method of a mixture for tire rubber compound

A process for producing a rubber compound for tires, where the ingredients of the rubber compound include: a polymer base containing an unsaturated chain which can be crosslinked with sulphur-based systems; at least one silica-based reinforcing filler; a silica-binding agent including a silane containing at least one sulphur atom; and a vulcanizing system. The process includes the steps of feeding the polymer base, the silica-based reinforcing filler, and the silica-binding agent ingredients continuously into a path for mixing and advancing an ingredient blend, wherein the mixing and advancing of the blend take place together. The path includes an initial stretch, an intermediate stretch, and a final stretch; each stretch defined between respective inlet and outlet sections. The process also includes controlling a heat profile of the blend in the initial stretch to maintain temperature and viscosity values for the blend in the outlet section of the initial stretch within defined ranges, and feeding the vulcanizing system continuously into the inlet section of the final stretch.

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Lodi, Italy

Antonio Proni