Abstract: An apparatus for mixing and ejecting fluid materials interacting with one another; said apparatus comprises at least a head having a mixing chamber with an outlet opening for the mixture at one end thereof, and having inlet ports, each of which connected to a supply line for a component. Each inlet port is connectable, through a distributing valve, with an orifice opening into the mixing chamber and respectively with an outlet port connected to a return line for a recycle at a first pressure rate of each component to a reservoir. A pin is reciprocable by a first double-acting cylinder to and away from the outlet opening of the mixing chamber; the distributing valves are operated by a second double-acting cylinder parallel connected to said first cylinder, one side of said second cylinder being directly connected to a pressure fluid source, and the other side being connected to pressure source by means of a shut off valve operable by the piston of the first cylinder at the end of its backward stroke.