Abstract: A component-feed nozzle for a reaction-mixing head of a reaction injection device includes a housing having a component inlet and a component outlet. Received in the housing is a closing and flow restriction member which is movable by a linear drive between at least two positions. In a first position, the closing and flow restriction member closes the component outlet, and in a second position clears the component outlet, thereby establishing a flow communication between the component inlet and the component outlet. The closing and flow restriction member has at least a first area and a second area, which generate forces in opposite directions, when the component pressure is applied, wherein the areas are sized in such a way that the opposing forces substantially offset one another.

Abstract: A mixing head includes a mixing device which is secured to a housing and has a mixing chamber for mixing at least two plastic components to form a material mixture. Received in a recess of the housing is a cleaning device which has a cleaning piston for back-and-forth movement in relation to the mixing chamber between a first position in which the cleaning piston is retracted from the mixing chamber and a second position in which the cleaning piston extends into the mixing chamber. The cleaning device has a barrier which interacts with a housing wall for pushing the material mixture radially outside. The barrier has a flank which has an incline which is steeper than an incline of the housing wall.

Abstract: A component-feed nozzle for a reaction-mixing head of a reaction injection device includes a housing having a component inlet and a component outlet. Received in the housing is a closing and flow restriction member which is movable by a linear drive between at least two positions. In a first position, the closing and flow restriction member closes the component outlet, and in a second position clears the component outlet, thereby establishing a flow communication between the component inlet and the component outlet. The closing and flow restriction member has at least a first area and a second area, which generate forces in opposite directions, when the component pressure is applied, wherein the areas are sized in such a way that the opposing forces substantially offset one another.

Abstract: A mixing head includes a mixing device which is secured to a housing and has a mixing chamber for mixing at least two plastic components to form a material mixture. Received in a recess of the housing is a cleaning device which has a cleaning piston for back-and-forth movement in relation to the mixing chamber between a first position in which the cleaning piston is retracted from the mixing chamber and a second position in which the cleaning piston extends into the mixing chamber. The cleaning device has a barrier which interacts with a housing wall for pushing the material mixture radially outside. The barrier has a flank which has an incline which is steeper than an incline of the housing wall.

Abstract: A mixing head for mixing at least two reactive starting materials includes a feed passageway for introduction of a high-viscosity starting material, and a return passageway for the high-viscosity starting material for allowing circulation of the high-viscosity starting material. The high-viscosity starting material can be introduced into a mixing chamber for subsequent mixing with a via at least one injection port. A switchover device is provided for selectively establishing a flow communication between the feed passageway and the mixing chamber and a flow communication between the feed passageway and the return passageway, wherein the flow communication between the feed passageway and the mixing chamber is provided upstream of the at least one injection port.

Abstract: A mixing head includes an integrated shot counting apparatus. The shot counting apparatus is hereby implemented as an integrated circuit with a detector for ascertaining an operating parameter of the mixing head, and an electric acquisition and storage unit operatively connected to the detector and having a counter and a non-volatile memory device which is operatively connected to the counter.