Elastomer masterbatch is processed in a continuous compounder having multiple parallel elongate rotors axially oriented in an elongate 
processing chamber. Optionally, additional materials are compounded into the 
masterbatch, e.g., additives, other elastomeric compositions, etc. Preferably, the 
masterbatch then is further processed in an open mill. Excellent control of 
Mooney Viscosity is achieved.In certain preferred embodiments, 
elastomer composites are produced by novel 
continuous flow methods and apparatus in which fluid streams of particulate filler and 
elastomer latex are fed to the 
mixing zone of a coagulum reactor to form a coagulated mixture in semi-confined flow continuously from the 
mixing zone through a coagulum zone to a 
discharge end of the reactor. The particulate filler fluid is fed under 
high pressure to the 
mixing zone, such as to form a 
jet stream to entrain 
elastomer latex fluid sufficiently energetically to substantially completely coagulate the elastomer with the particulate filler prior to the 
discharge end without need of adding acid or 
salt solution or other coagulation step. The coagulated elastomer and particulate filler composite is fed into the aforesaid continuous compounder for 
processing and control of its 
moisture level and 
Mooney Viscosity. Novel 
elastomer composites are produced. Such novel 
elastomer composites combine material properties and characteristics, such as choice of filler, elastomer, level of filler loading, 
moisture level, 
Mooney Viscosity, balance between molecular weight and amount of bound rubber, and 
macro-dispersion not previously achieved.