Method of injection molding of thermoplastic materials using the optimum

Abstract

A method of injection molding thermoplastic material from an injection molding machine including a slidable screw into a mold whose optimum pattern of the injection rate has been determined on and is known for another injection molding machine. The method includes transferring the defined optimum characteristic values for a first injection molding machine onto a second injection molding machine. The known optimum injection flow rate pattern (V.sub.A) of a previously used first injection molding machine is introduced manually and/or by means of data carriers into a control device of a second injection molding machine to be used. The second injection molding machine is operated with any compatible injection flow rate pattern (V.sub.b), with the resulting injection time (t.sub.Eb) being adjusted to that of the first injection molding machine by means of a multiplicative change of the injection flow rate pattern. Forming an adjustment factor K.sub.V =V.sub.b /V.sub.A as the quotient of the average integral injection flow rate patterns. Finally, the optimum injection flow rate pattern (V.sub.B (t)) of this injection molding machine is formed in the control device of the second injection molding machine is formed in the control device of the second injection molding machine for the mold to be filled by means of the calculation V.sub.B (t)=K.sub.V. V.sub.A (t) and developing by means of another calculation from V.sub.B (t) the corresponding injection distance pattern (V.sub.B (s)).