Process for producing flowable polymer compounds for the reaction injection moulding of solid bodies of plastic and apparatus for carrying out the process

摘要

The invention relates to a process for producing flowable polymer compounds for the reaction injection moulding of solid bodies of plastic and an apparatus for carrying out the process, each component of the compound being injected through a separate nozzle (4) under pressure into a mixing chamber (1) - if appropriate provided in its outlet with a movable baffle barrier - after this pressure has been built up for each component in advance in a separate circuit comprising accumulator (6), feedline (10) with pump (7), nozzle (4) with opening and closing mechanism and return line (49) with throttling device (48). The opening and closing mechanism preferably comprises a hydraulic piston-cylinder arrangement (29), the piston (27) of which is enclosed between two - or two groups of - outlets (23, 24) of a servo valve (21), which for its part is driven by the output signals of a pressure sensor (14) by means of a suitable open-loop and closed-loop control unit (15). The principle of pressure-controlled regulation of the nozzle opening (13) is also used for regulating the throttling device (48) and - if there is one - the position of the baffle barrier in the outlet of the mixing chamber (1).