Method for producing thermoplastic moulding compounds

A method for producing thermoplastic molding compounds, comprising:

• (a) feeding a dispersion containing a rubber and a precipitation solution into a precipitating container, to generate an aqueous suspension containing rubber particles;
• (b) optionally sintering the rubber particles contained in the aqueous suspension containing rubber particles, to give larger particles;
• (c) mechanically dewatering the aqueous suspension containing rubber particles, to obtain rubber particles containing residual moisture and a liquid phase containing finely divided rubber;
• and
• (d) feeding the rubber particles containing residual moisture into an extruder,
• wherein the extruder comprises:
• an intake zone, into which the rubber particles containing residual moisture are fed;
• a dewatering section, in which a liquid phase containing residual rubber is removed from the rubber particles containing residual moisture;
• at least one feed section for at least one further polymer and/or additives;
• a mixing section, in which the rubber particles containing residual moisture and the at least one further polymer and/or additives are mixed together to give a melt of the thermoplastic molding compound;
• and
• a discharge zone, through which a melt strand is extruded from the extruder,
• wherein the liquid phase containing residual rubber that is removed in the dewatering section is collected in a buffer container, and
• wherein the buffer container comprises at least one stirrer with which the liquid phase containing residual rubber is stirred to prevent accumulation of the rubber particles still contained in the liquid;
• and
• (e) returning the liquid phase containing residual rubber collected in the buffer container to the precipitating container.