Mixing head esp. for polyurethane foam - has oblique component feed ducts with side nozzles and internal slide valves

摘要

A mixing head for mixing together two or more fluid components, esp. for the mould-foaming of polyurethane, has a long narrow, pref. cylindrical mixing chamber into which nozzles lead transversely from supply ducts. These component supply ducts have their longitudinal axes at an acute angle to the longitudinal axis of the mixing chamber, considered in the discharge direction, and the nozzles lead into the mixing chamber at the point where the supply duct is nearest to the mixing chamber. Pref. the angle between the longitudinal axes of the supply ducts and mixing chamber is less than 45 deg., more specifically approx. 20 deg., and two material supply ducts reach it at the same angle. An internal tube can be axially displaced inside the component supply duct to block the outlet nozzle. Particularly for polyurethane foaming. The apparatus is compact and narrow. In each component supply duct, when the outlet nozzle is blocked, the material can flow back through a recirculating system.