Injection Molding Pressure Curve Mapping Without Mold Sensors
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Solution Overview
Problem
Current injection molding processes require expensive sensor installations in each injection mold to determine machine-independent process parameters, making them costly and inefficient for monitoring and controlling the quality of the injection molding process, especially when changing machines.
Innovation Solution
A method that uses geometric data of the injection mold and molded part to determine a virtual pressure curve and event pattern, allowing for the derivation of process parameter values without the need for direct sensor measurements within the mold, by analyzing pressure curves and assigning characteristic event patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pressure and/or temperature sensors are installed directly in the cavity of the injection mold to determine machine-independent process parameters, then measurement precision is improved, but device complexity and cost increase significantly
Solution Approach 1:
The patent creates a virtual model that copies the essential geometric characteristics of the injection mold cavity and uses simulation to generate a virtual pressure curve. This virtual representation allows determination of process parameters without physical sensors in the cavity, resolving the contradiction between measurement precision and device complexity
Solution Approach 2:
The patent replaces the mechanical sensor installation system with a computational system. Instead of using physical pressure and temperature sensors in the mold cavity, the invention uses geometric data processing and virtual simulation to determine process parameters, eliminating the need for complex sensor installations while maintaining measurement capability
2Adaptability or versatility
If sensors are installed in each injection mold cavity to enable quality monitoring and machine changes, then adaptability is improved, but manufacturing cost increases
Solution Approach 1:
The patent creates a universal method that can be applied to any injection mold by using its geometric data. The virtual model approach and event pattern recognition system are mold-agnostic, allowing the same methodology to determine process parameters across different molds and machines without requiring mold-specific sensor installations, thus achieving machine independence while keeping tools inexpensive
3Device complexity
If geometric data and virtual simulation are used to determine process parameters without sensors in the mold, then device complexity is reduced, but measurement precision may be compromised
Solution Approach 1:
The patent performs preliminary simulation to generate a virtual pressure curve and identifies characteristic event patterns before actual injection molding. By pre-establishing the relationship between geometric data, virtual pressure events, and process parameters, the system can accurately determine actual process parameters from actual pressure curves without sensors in the mold, maintaining precision while reducing complexity
Data Source
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AI summary
Described is a method for determining a number of process parameter values in an injection molding process within an injection mold (1F). In this method, geometric data for the injection mold (1F) and/or a molded part (1, 1', 1") which is to be produced in the injection mold (1F) are determined. Using the geometric data, a virtual molded part-specific pressure curve (ps) of an injection molding process is determined, on the basis of which a molded part-specific event pattern (Ms) is determined which comprises a plurality of singular virtual events (ES1, ES2, ES3,...) which are linked with characteristic event locations (F1, F2, F3,...) in the molded part geometry and with each of which is associated at least one item of relative time information (tS1, tS2, tS3,...) and at least one item of position data which defines a position of a melt front (SF) of the injection molding material (KS) in the injection mold (1F). In addition, an injection molding process is carried out using an injection mold (1F) and a measurement pressure curve (pm) is determined during the injection molding process, on the basis of which measurement pressure curve a measurement event pattern (Mm) is determined, the measurement event pattern (Mm) having a plurality of singular measurement events (Em1, Em2, Em3,...) with which at least one item of time information (tm1, tm2, tm3,...) is associated. Virtual events (ES1, ES2, ES3,...) of the molded part-specific event pattern (Ms) are brought into association with measurement events (Em1, Em2, Em3,...) of the measurement event pattern (Mm). The process parameter values are derived on the basis of the position data and the time information (tm1, tm2, tm3,...) associated with the virtual events (ES1, ES2, ES3,... ) and associated with the measurement events (Em1, Em2, Em3,...) associated with these virtual events (ES1, ES2, ES3,... ). Furthermore, methods for controlling an injection molding system (10) and for visualizing an injection molding process in an injection molding system (10) are described. In addition, a corresponding process parameter value-determining device (20) and an injection molding system (10) having such a process parameter value-determining device (20) are described.