Method for the production of plastic moulded parts

A method for the production of plastic moulded parts, with a plasticizing unit (3), which has a cylinder (4) and a plasticizing screw (5) able to be driven rotatably and linearly in the cylinder (4), wherein a plastic material (34) which is to be melted is fed into the cylinder (4) via an opening (8) in the cylinder (4), wherein the plastic material (34) is fed into the cylinder (4) by means of a volumetric metering device (30), wherein the volumetric metering device (30) has a storage container (31) for the receiving of plastic material (34), a rotatable metering element (32) and a rotary drive (33) for actuating the metering element (32), and wherein molten plastic material is injected into a moulding tool (2) by an injection stroke of the plasticizing screw (5),

• wherein
• the ACTUAL mass flow of the plastic material (34) is calculated, wherein the ACTUAL mass flow is calculated from the return speed vscrew,back,n of the plasticizing screw (5) during a melt metering process, the nominal diameter of the plasticizing screw (5) and the melt density, that the ACTUAL mass flow of the plastic material (34) is compared with a TARGET mass flow of the plastic material (34), and that with a predeterminable difference value between the ACTUAL mass flow of the plastic material (34) and the TARGET mass flow of the plastic material (34) the rotation speed nd of the rotary drive (33) of the metering element (32) is changed in such a way that the difference value is reduced.