Appts. for multicomponent plastics, esp. polyurethane, prodn. - in which each component is accurately metered using metering pump regulated by flow measuring device

摘要

A device for producing multi-component plastics comprises a mixing chamber for each separate component and a metering pump to supply the component from this chamber through a volumetric measuring device to the receiving point, leading to the mixing chamber for all the components. The measuring device is equipped with a servomotor and the torque to this servomotor is regulated by pressure measurements upstream and downstream of the metering device, so that there is no difference between these pressures. The measuring device typically comprising a bladed rotor providing exact volumes of the flow of material, operates with no pressure difference across it, so that no errors occur due to difference in pressure and leakage past the blades.