Mixing additives-plastics with removal of volatiles - by downwardly introducing additives, then upwardly introducing plastic into extruder

摘要

Incorporation of (I) additives, e.g. fillers, plasticisers, pigments, stabilisers or lubricants, into (II) plastic matls. is affected with simultaneous elimination of volatile components, in a horizontal extruder for heating, mixing, transporting and extruding the mixt. by (a) initially introducing (I) into the extruder (1) in a downwards direction (4) in the advancement direction of the prod. (b) next introducing (II) as a molten mase, soln. or dispersion in an upwards direction (b), and (c) allowing the major part of the volatile components to escape from the extruder by an orifice (8) placed vertically above the feed orifice (b) for (II). Process combines efficient removal of volatiles with rapid mixing, transport and extrusion of the prod. with low heat/energy ratio.