Method for introducing an additive into a flowing medium stream

A method for introducing an additive into a flowing medium stream comprising the steps of

• extruding a plastic melt from a front chamber of an extruder into a mold;
• positioning a nozzle with an exit end in fluid communication with the plastic melt;
• introducing an additive from the exit end of the nozzle into said melt at a pressure at least higher than the pressure of said melt and at variably set time periods to pulse discrete quantities of said additive into said melt with sufficient intensity to cause said pulses of additive to penetrate into and subsequently mix with said melt and to result in a substantially homogenous mixture of said additive and said melt;
• said additive being introduced into said plastic melt at a location selected from the group consisting of the front chamber of the extruder, the mold and channels leading to the mold downstream of the extruder.

The method of introducing an additive into a flowing medium stream comprising the steps of

• providing a nozzle having a nozzle bore with an exit end;
• positioning a movable needle within said nozzle bore, said needle having a needle bore and a plurality of outlet orifices communicating said needle bore with said nozzle bore;
• positioning a movable needle valve in said needle bore;
• introducing a stream of medium into said nozzle bore at a first pressure;
• introducing a flow of additive into said needle bore at a second pressure;
• regulating the movement of said needle valve to cause pulses of additive to pass from said needle bore through said outlet orifices into said nozzle bore for mixing with the medium therein while regulating the movement of said needle to cause the mixture of medium and additive to pass from said nozzle bore through said exit end.

A method for blending a viscous additive with a viscous medium having different physical and/or chemical characteristics from said additive comprising the steps of

• flowing said viscous medium at a set velocity and medium pressure in a conduit;
• injecting discrete quantities of said additive into the viscous medium in the conduit as pulses of a set frequency and duration at a set additive pressure higher than said medium pressure;
• and
• mixing said additive and said medium into a substantially consistent mixture downstream of the position whereat said additive is injected into said viscous medium.