摘要 |
<p>1. A mixing head for mixing at least two inter-reacting, liquid plastics components, comprising metering means (2) for each liquid plastics component and a mixing chamber (3) which has inlets (7, 8) for the individual components and an outlet (9) for the mixture of components, as well as a control member (4), by means of which the inlets (7, 8) can be connected to recycle lines (10, 11) synchronously with their being shut off from the mixing chamber (3), wherein a venting line (12) is connected to the suction side of the metering means (2) ; the venting line (12) is connected to the recycle line (10, 11) concerned ; and a pressure which is lower than in the recycle line (10, 11) can be set up in the venting line (12), the difference in pressure being produced by a liquid jet pump (13) arranged in a bypass (14) of the recycle line (10, 11), and a check valve (15) being arranged in the recycle line (10, 11), parallel to the liquid jet pump (13).</p> |