A rubber composition manufacturing method comprises an operation in which at least rubber, silica, and silane coupling agent are kneaded in an internal kneader at not less than a temperature lower limit for a coupling reaction between the silica and the silane coupling agent to proceed. For at least a portion of time during which that operation is being carried out, a compressed gas is delivered to the kneading chamber while the ram is in a nonpressing state.

A method for producing a rubber composition containing a rubber wet master batch has a masticating process. The masticating process comprises step 1 of charging the rubber wet master batch into an enclosed kneading chamber that has a stirring rotor showing a rotation speed controllable automatically through a control unit and that is capable of detecting and outputting an internal temperature, step 2 of setting a first control time and a first target temperature in the control unit, and step 3 of stirring the inside of the kneading chamber while making a PID control for adjusting an actually measured temperature in the kneading chamber to the first target temperature through the control unit on the basis of information on the actually measured temperature and the first target temperature, thereby automatically controlling the rotation speed, until the first control time elapses after the completion of the two steps.

The invention is directed to an apparatus for making a finished rubber mixture which includes a reactive additive. The apparatus includes a tandem mixer with an upper machine having an upper mixing chamber and a lower machine having a lower mixing chamber. The lower mixing chamber is larger than the upper mixing chamber and there are rotors disposed in each mixing chamber. Mixture components are introduced into the lower mixing chamber via a loading shaft of a loading unit. The loading unit has at least two metering devices, a cutting or preheating unit connected upstream of a metering device and a first conveyor belt to the loading shaft. All conveyor belts of the apparatus can be switched on and off automatically, such that mixture components weighed in can be held in a “wait position” thereon.

A rubber extruding device for kneading and extruding unvulcanized rubber material, the rubber extruding device includes a mixer for kneading unvulcanized rubber material in a substantially closed mixing chamber, and an extruder comprising a rotatable screw shaft for kneading further the unvulcanized rubber material received from the mixer and for extruding the same, and at least one deaerator for sucking up a gas in the extruder.

A kneader includes a kneader main body including a casing including a kneading chamber and a kneading portion that is disposed in the casing and kneads a material in the kneading chamber. The material supplied to the kneading chamber includes a resin material, an inorganic additive added to the resin material, and a coupling agent for enhancing affinity of the inorganic additive for the resin material. The kneader further includes a kneading monitoring portion that monitors a kneading state of the material by detecting a reaction product that is generated by a reaction between the coupling agent and the inorganic additive.

A sealed kneading machine includes a kneading chamber to which a material to be kneaded is supplied, and a rotor disposed in the kneading chamber to be able to rotate about a rotor shaft. The rotor includes a plurality of kneading blades for kneading the material to be kneaded, and the length of all the kneading blades in the rotor shaft direction of each thereof is 45% or less of the total length of the rotor in the rotor shaft direction.

The invention is directed to an apparatus for making a finished rubber mixture which includes a reactive additive. The apparatus includes a tandem mixer with an upper machine having an upper mixing chamber and a lower machine having a lower mixing chamber. The lower mixing chamber is larger than the upper mixing chamber and there are rotors disposed in each mixing chamber. Mixture components are introduced into the lower mixing chamber via a loading shaft of a loading unit. The loading unit has at least two metering devices, a cutting or preheating unit connected upstream of a metering device and a first conveyor belt to the loading shaft. All conveyor belts of the apparatus can be switched on and off automatically, such that mixture components weighed in can be held in a wait position thereon.

The relative displacement in the axial direction between an outer ring fixing member or casing and an inner ring fixing member or rotor is determined, said outer ring fixing member being a member for affixing an outer ring of a bearing on one side, and said inner ring fixing member being a member for affixing an inner ring of the bearing on the one end side. When calculating a thrust load acting on the rotor by multiplying the determined relative displacement by a conversion coefficient, an axial force measuring bolt is used as a tightening bolt for affixing the bearing on the one end side, said axial force measuring bolt enabling measurement of a load acting in the axial direction. The axial force measured by the axial force measuring bolt and the relative displacement during measurement of the axial force are used to calibrate the conversion coefficient.

A device for measuring a thrust load acting on a rotor of a hermetically sealed kneader includes displacement sensors (19) and a load-calculating member. The displacement sensors (19) are configured to measure relative displacement along the axial direction of an outer ring-fixing member (17), which is for fixing the outer ring (16) of one end of a bearing (6), or a casing (18) with respect to an inner ring-fixing member (20), which is for fixing the inner ring (13) of the one end of the bearing (6), or the rotor (5). The load-calculating unit calculates the thrust load acting on the rotor (5) by multiplying the relative displacement measured by the displacement sensors (19) by a conversion coefficient.

A mixer includes: a casing having an introduction port at an upper portion and having a rotor provided with a blade portion for mixing a material to be mixed, inside thereof; a floating weight which blocks the introduction port; and a floating weight moving mechanism which has a horizontal movement unit capable of horizontally moving the floating weight in a supported state between a delivery position just above the introduction port and a retracted position being lateral to the introduction port, on the upper side of the introduction port, and can move the floating weight separately from the horizontal movement unit from the delivery position to a blocking position at which the floating weight blocks the introduction port.