Method for the production of plastic moulded parts

A method for the production of plastic moulded parts, comprising:

• driving a plasticizing screw rotatably and linearly within a cylinder of a plasticizing unit,
• feeding a plastic material to be melted into the cylinder via a first opening in the cylinder a volumetric metering device,
• storing the plastic material in storage container of the volumetric metering device,
• actuating a rotatable metering element of the volumetric metering device by a rotary drive,
• separately adding a fibre material into the cylinder by feeding endless fibre strands via a fibre braking device and/or feeding cut fibres via a gravimetric metering device to the plasticizing unit,
• mixing the plastic material with the fibre material to create a mixture, and injecting the mixture into a moulding tool by an injection stroke of the plasticizing screw,
• the method further comprising the steps of:
• determining a linear return speed vscrew,back,n of the plasticizing screw during a melt metering process, a nominal diameter of the plasticizing screw, and a melt density,
• calculating an ACTUAL mass flow of the plastic material from the linear return speed vscrew,back,n of the plasticizing screw during the melt metering process, the nominal diameter of the plasticizing screw, and the melt density,
• comparing the ACTUAL mass flow of the plastic material with a TARGET mass flow of the plastic material,
• determining a difference value between the ACTUAL mass flow of the plastic material and the TARGET mass flow of the plastic material, and
• changing a rotation speed nd of the rotary drive of the rotatable metering element in such a way that the difference value is reduced.