Method and High-Pressure Mixing Device for the Co-Injection of Polymeric Components

A method for mixing a first and at least a second polymeric reactive component by a self-cleaning high-pressure mixing device comprising a pressure chamber configured with a forwardly converging fore portion in fluid communication with a mixing chamber through a settable co-injection orifice;

• comprising the steps of:
• feeding the first and at least the second reactive components into the pressure chamber maintaining the reactive components inside the pressure chamber at a same pressure and in an unmixed state;
• flowing the reactive components at said pressure and in the unmixed state, into the pressure chamber and into the forwardly converging fore portion to increase the flow velocity;
• configuring the co-injection orifice in the form of an elongated restriction longitudinally extending to the mixing chamber, transversely oriented and intersecting the forwardly converging fore portion of the pressure chamber;
• adjusting the pressure of the unmixed reactive components in the pressure chamber, setting an open section of the elongated restriction of the co-injection orifice by adjusting, in respect to the same co-injection orifice, the fore end position of the second cleaning member at the retracted condition thereof;
• and
• co-injecting the unmixed reactive components into the mixing chamber, causing a pressure drop and mixing the reactive components, while they are flowing through the set open section of the co-injection orifice and into the mixing chamber of the mixing device;
• and
• ejecting the remaining unmixed reactive components from the pressure chamber and from the forwardly converging fore portion, and ejecting a remaining mixture from the mixing chamber, by first and respectively second cleaning members having a fore end, the cleaning members being reciprocable between a retracted and an advanced condition in the pressure, respectively in the mixing chamber of the mixing device.