Injection Molding Controller for Viscosity-Adaptive Filling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional injection molding machines face challenges in producing thin-walled parts with high L/T ratios due to high pressures and equipment costs, and fail to adjust operating parameters for changes in material properties, leading to inefficiencies and lower quality parts.

Innovation Solution

The implementation of a low constant pressure injection molding system that uses a controller to monitor and adjust melt pressure and flow rate in real-time, maintaining a substantially constant pressure to ensure complete filling of the mold cavity despite changes in material viscosity, using sensors to correct the process and maintain a dynamic flow front throughout the cavity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If high filling rates are used to fill thinwall parts before polymer solidifies, then complete cavity filling is achieved, but very high power loads and expensive molding equipment are required

Engineering Contradiction:
Improvecavity filling completenessVSAvoidpower load
Core Design Contradiction:
Manufacturing precisionVSPower

Solution Approach 1:

The injection molding machine dynamically adjusts the filling rate during the injection process based on real-time material property changes. The controller modifies injection parameters mid-cycle to maintain optimal filling velocity without requiring sustained peak power loads, thereby reducing overall power consumption while ensuring complete cavity filling.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes physical parameters (injection pressure, temperature, filling rate) during the molding process to account for material viscosity changes. By adjusting these parameters dynamically, the machine maintains effective filling velocity without requiring constantly high power levels, thus resolving the contradiction between complete filling and power load.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If high filling rates are used to fill thinwall parts, then complete cavity filling is achieved, but very high clamping forces and expensive molding equipment are required

Engineering Contradiction:
Improvecavity filling completenessVSAvoidclamping force
Core Design Contradiction:
Manufacturing precisionVSForce

Solution Approach 1:

The clamping force is dynamically adjusted during the injection cycle based on real-time feedback about material properties and filling progress. The controller reduces clamping force when high filling rates are not needed and increases it only when necessary to maintain mold closure, thereby reducing overall equipment requirements while ensuring complete cavity filling.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operating parameters including clamping force levels during the injection process. By coordinating clamping force adjustments with filling rate modifications, the system maintains complete cavity filling without requiring sustained high clamping forces, thus reducing equipment cost requirements.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If conventional injection molding machines operate with fixed parameters, then equipment simplicity is maintained, but changes in material properties lead to incomplete filling or defects

Engineering Contradiction:
Improvecontrol system simplicityVSAvoidpart quality
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The injection molding machine incorporates sensors that continuously monitor material properties during the molding process. This feedback information is sent to the controller, which automatically adjusts injection parameters to compensate for material variations, thereby maintaining high part quality without requiring complex manual intervention or overly complicated control systems.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment of injection parameters based on real-time material property detection. The controller automatically modifies filling rates, pressures, and temperatures without operator intervention, allowing the machine to adapt to material changes while maintaining relatively simple overall system architecture and ensuring consistent part quality.

Inventive Principle:
Principle #25Self-service

4Manufacturing precision

If high pressures are used to fill thinwall parts, then complete cavity filling is achieved, but equipment costs and operational costs increase

Engineering Contradiction:
Improvecavity filling completenessVSAvoidpolymer material efficiency
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The system dynamically changes injection pressure and temperature parameters during the molding process to optimize material flow. By adjusting these parameters in response to real-time material property changes, the system achieves complete cavity filling at lower overall pressure levels, reducing both equipment requirements and polymer material waste from defects or rejections.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach allows for the production of high-quality thin-walled parts with reduced equipment costs, increased efficiency, and improved part consistency by maintaining a constant pressure and flow rate, even when material properties change, thus overcoming the limitations of conventional high-pressure injection molding.

Implementation Method 1

sensors to detect changes in material viscosity

Methodology Applied
Scientific EffectViscosity measurement:

Implementation Method 2

the controller adjusts injection parameters based on detected viscosity changes to maintain constant pressure

Methodology Applied
Scientific EffectPressure control:

Data Source

PatentEP3027380B1Injection molding machines and methods for accounting for changes in material properties during injection molding runs
Publication Date: 2019.06.19 IMFLUX INC
  • EP3027380B1 patent drawingFigure 1
  • EP3027380B1 patent drawingFigure 2
  • EP3027380B1 patent drawingFigure 3

AI summary

A method and a machine that account for changes in material properties of molten plastic material during an injection run. If viscosity of the molten plastic material changes during an injection run, a controller alters a step time of the injection cycle to ensure that molten plastic material completely fills and packs a mold cavity to prevent part flaws such as short shots or flashing.