Methods of preparing a composite having elastomer and filler

A method of preparing a composite, comprising:

• (a) charging a mixer having one or more rotors with at least a solid elastomer and a wet filler comprising a filler and a liquid present in an amount of at least 15% by weight based on total weight of wet filler;
• (b) in one or more mixing steps, mixing the at least the solid elastomer and the wet filler to form a mixture and removing at least a portion of the liquid from the mixture by evaporation, and in at least one of said mixing steps conducting said mixing wherein at least one of the following applies:
• (i) the mixer has at least one temperature-control means that is set to a temperature, Tz, of 65° C. or higher, and
• (ii) the one or more rotors operate, for at least 50% the mixing time, at a tip speed of at least 0.6 m/s;
• and
• (c) discharging, from the mixer, the composite comprising the filler dispersed in the elastomer at a loading of at least 20 phr, wherein the composite has a liquid content of no more than 10% by weight based on total weight of said composite,
• wherein the one or more rotors is mechanically coupled to a mixer motor, and at least a portion of the mixing in step (b) is performed under power control in which the rotational speed of the one or more rotors is controlled by a controller that (i) calculates a difference between a measured mixer motor power and a power set point and (ii) adjusts the rotational speed of the one or more rotors if the measured mixer motor power deviates from the power set point.