Abstract: A process for preparing organopolysiloxane compositions (A) having a viscosity measured at 25° C. of at least 500 Pa·s., wherein organopolysiloxanes (O) and fillers (F) are mixed and kneaded in a first process stage in a kneading cascade having at least two kneading chambers arranged in series adjacent one another, each containing kneading tools having parallel axes and capable of being driven in co-rotating or counter-rotating directions, the chambers connected to one another by means of openings through which material can pass in a direction transverse to the axes of the kneading tools, with the first kneading chamber having a feed opening and the last kneading chamber having a discharge opening, to give raw mixtures, and the raw mixtures are kneaded and degassed in a reciprocating kneader in a second process stage.

Abstract: A process for the continuous production of organopolysiloxane compositions which vulcanize at elevated temperature and have a viscosity of at least 500 Pa·s at 25° C., involves mixing and homogenizing high-viscosity organopolysiloxanes and crosslinking additives in a kneading cascade having at least two kneading chambers arranged in series proximate one another, containing two axially parallel kneading tools which can be driven in the same or opposite directions, and which are connected to one another by means of openings transverse to the axes of the kneading tools, with the first kneading chamber having a feed opening and the last kneading chamber having a discharge opening, and the temperature in the kneading chambers containing crosslinking additives being not more than 95° C.

Abstract: A process for preparing organopolysiloxane compositions (A) having a viscosity measured at 25° C. of at least 500 Pa·s., wherein organopolysiloxanes (O) and fillers (F) are mixed and kneaded in a first process stage in a kneading cascade having at least two kneading chambers arranged in series adjacent one another, each containing kneading tools having parallel axes and capable of being driven in co-rotating or counter-rotating directions, the chambers connected to one another by means of openings through which material can pass in a direction transverse to the axes of the kneading tools, with the first kneading chamber having a feed opening and the last kneading chamber having a discharge opening, to give raw mixtures, and the raw mixtures are kneaded and degassed in a reciprocating kneader in a second process stage.

Abstract: The invention relates to a process for preparing rubber compositions which include gas-containing solid material, in which the solid material is compacted by degassing immediately prior to mixing with rubber base polymer.

Abstract: The invention relates to a process for the continuous preparation of HTV silicone compositions, which comprises mixing and homogenizing 100 parts by weight of diorgano(poly)siloxane which has a viscosity of 50 to 100,000 Pas at 25.degree. C. with at least 20 parts by weight of finely divided silicon dioxide which has a tamped density of more than 0.01 kg/l in an oscillating single-shaft pilgrim-step kneader.