Abstract: Apparatus for high pressure impingement mixing includes a mixing chamber and aftermixer chamber located on opposite sides of, and perpendicular to, a transfer dispense chamber. Two or more reactive components are injected into the mixing chamber. The resultant mixture is directed across the transfer dispense chamber into the aftermixer chamber, and from the aftermixer chamber back into the transfer dispense chamber and around the crossing mixture to the outlet of the transfer dispense mixer for dispensing. Each chamber includes a plunger which is actuated sequentially to interrupt mixing and clean the respective chamber. The device provides effective and intimate mixing of the reactive components and dispenses a stable emulsion so that the device can be used in applications presently suitable only for low pressure mixing devices. It may also be used in existing high pressure applications but without the need for conventional aftermixer devices and gating systems disposed in the forming molds.

Abstract: A mixing head for a high velocity reaction injection apparatus for mixing and dispensing two or more liquid components. The mixing head includes a mixing chamber with two or more inlets for the separate components and an outlet for dispensing the mixed components, and an injection housing for injecting each component through a corresponding inlet. Component flow is directed through a flow accelerating passage in the injection housing prior to injection into the mixing chamber, for imparting a pressure drop in the component on the downstream side of the passage, and means are provided for selectively blocking the inlets for terminating the dispensing of the mixed components and thereby increasing the component pressure in the injection housing downstream of the passage.