Patent ID: 6969247

Claim:
An injection unit of an injection molding machine, comprising: a housing having an inner diameter; an injection device received in the housing for carrying out axial and rotating movements and including a screw constructed for plasticizing plastic granulate during transport thereof into plastic melt and including a backflow prevention assembly, a plunger for pressing the plastic melt from an accumulation chamber through a nozzle into an injection mold, and a spacer element arranged between the backflow prevention assembly of the screw and the plunger and having a length corresponding at least to a stroke of the injection device, with the spacer element having a first flow channel for establishing in each position of the injection device a fluidic communication with a second flow channel which initially extends radially outwards and then parallel to a movement and guide area of the plunger to an area between the nozzle and the plunger; and a mixing and metering device embracing the plunger at least partially in a circular ring shaped manner for mixing and metering plastic melt and including an inlet for introduction of an additive, wherein the second flow channel extends through the mixing and metering device adjacent to the movement and guide area of the plunger, said mixing and metering device being in driving relationship with the injection device and including a rotatable tube in fixed rotative connection with the plunger, and a plurality of mixing elements arranged on the tube and on the inner diameter of the housing.