Kraussmaffei Technologies Gmbh

Reinhard Schiffers

Stefan Moser

Stefan Kruppa

Matthias Busl

Johannes Wortberg

A method for determining an actual volume Vr of an injection-moldable compound during an injection-molding process is disclosed. The injection-moldable compound is introduced into at least one cavity of the mould. The method includes the steps of: a) determining a theoretical volume Vt from process variables at least during a filling phase of the injection-molding process, b) determining and/or measuring at least one value for at least one compound pressure pM, c) selecting a material-specific compression k (p), corresponding to the value of pM, of the injection-moldable compound, and d) calculating an actual volume Vr by taking into account the compression k (p).

Method for determining an actual volume of an injection moldable compound in an injection molding process

In a method for operating an injection moulding machine in the absence of a backflow barrier, plastic melt is injected by a plasticising device into a cavity in a screw antechamber of a plasticising screw adapted to rotate about a longitudinal axis and to move translationally by a drive unit during an injection phase and a holding-pressure phase. A rotational drive of the drive unit is controlled such that a speed of the plasticising screw causes overlay of a backflow of the plastic melt from the screw antechamber back into screw threads of the plasticising screw by an opposing delivery flow as a result of a rotation of the plasticising screw due to a translational injection movement of the plasticising screw. A differential flow is established from the backflow and the opposing delivery flow and influenced at least during the injection phase by influencing the speed of the plasticising screw.

Method for operating an injection moulding machine

The invention relates to a method for qualitatively and/or quantitatively classifying injection-molding tools in tool categories and determining preferred intervention ranges and/or manipulated variables for adapting injection-molding machine parameters in the case of changing ambient conditions and/or determining the influence of disturbing effects on the injection-molding process, comprising the following steps: a) providing an injection-molding machine having the injection-molding tool which is to be classified and which is intended for the determination, b) performing at least one injection-molding cycle with injection-molding machine settings in order to obtain a qualitatively adequate injection-molding part, c) determining a quotient Q=&#x394;p/&#x394;s or Q=&#x394;sn/&#x394;se characterizing the tool from c.1) a pressure rise &#x394;p during the compression phase of the injection-molding cycle and the melt volume &#x394;V displaced during the compression phase or c.2) a melt volume &#x394;Vn displaced during the holding-pressure phase and the melt volume &#x394;Ve displaced during the injection phase, wherein c.3) the corresponding screw travel &#x394;s, &#x394;sn, and &#x394;se is measured in order to determine the displaced volumes &#x394;V, &#x394;Vn, and &#x394;; Ve, d) providing at least one limit value (G1 . . . Gx . . . Gn), wherein one or more recommendations for preferred intervention ranges or manipulated variables for adapting adjustment parameters of the injection-molding machine are associated with ranges (Q&#x3c;G1; G1&#x3c;Q&#x3c;G2; . . . Gn-1&#x3c;Q&#x3c;Gn; Q&#x3e;Gn) for the values of the quotient Q, e) determining in which of the ranges (Q&#x3c;G1; G1&#x3c;Q&#x3c;G2; . . . Gn-1&#x3c;Q&#x3c;Gn; Q&#x3e;Gn) the value of the quotient Q lies, and f) outputting the preferred intervention ranges and/or manipulated variables for adapting the machine parameters of the injection-molding machine which are associated with the determined range.

Method for evaluating process characteristics of injection-molding tools

The invention relates to a method for filling a mold cavity of a molding tool in a volumetrically correct manner. A molded part/volume equivalence is ascertained during a learning phase, and production injection-molding cycles are influenced during a production phase such that the molded part/volume equivalence ascertained during the learning phase is also satisfied during the production injection-molding cycle.

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Munich, Germany

Reinhard Schiffers