Stretch Rod Foaming Control in Container Forming

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Solution Overview

Problem

Existing methods for forming and filling containers from preforms lack precision in molding operations, fill point adjustment, and effective removal of air and foam within the containers.

Innovation Solution

A system that simultaneously forms and fills containers by injecting fluid through a nozzle passage, using a seal pin to close the passage and trap fluid and air, and then extracts air, fluid, and foam through a passageway in a stretch rod to adjust the fill point, allowing for precise control of the fill level and pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If fluid is injected through a nozzle passage to simultaneously form and fill the container, then productivity is improved, but manufacturing precision deteriorates due to lack of control over fill point and air/foam removal

Engineering Contradiction:
Improvesimultaneous forming and fillingVSAvoidfill point control
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The system segments the filling process into distinct phases: initial filling through the nozzle passage, followed by seal pin actuation to close the passage, then stretch rod actuation to create a passageway for air and foam removal, and finally vacuum application to remove remaining air and foam. This segmentation enables precise control over the fill point while maintaining productivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The seal pin is actuated to close the nozzle passage before the stretch rod is fully inserted, preliminarily trapping fluid and air within the container under pressure. This preliminary action creates a closed system that enables subsequent precise control of the fill point through the stretch rod passageway.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the seal pin is actuated to close the nozzle passage and trap fluid and air, then manufacturing precision is improved through better pressure control, but device complexity increases due to additional actuation mechanisms

Engineering Contradiction:
Improvepressure controlVSAvoidactuation mechanisms
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The seal pin serves multiple functions: it closes the nozzle passage to trap fluid and air, creates a sealed environment for pressure control, and works in conjunction with the stretch rod to enable fill point adjustment. This multi-functionality reduces the need for separate dedicated components for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The seal pin actuation and stretch rod actuation are combined into a coordinated sequence where the seal pin closes the passage first, then the stretch rod inserts to create the passageway. This merging of actions into a single coordinated mechanism reduces overall system complexity while achieving precise pressure control.

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If air and foam are extracted through a passageway in the stretch rod, then manufacturing precision is improved through accurate fill level control, but device complexity increases due to the stretch rod passageway requirement

Engineering Contradiction:
Improvefill level controlVSAvoidstretch rod passageway
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The stretch rod serves multiple functions: it stretches the preform during forming, creates a passageway for air and foam removal through its insertion, and enables fill level control by regulating the extraction of air and foam. This multi-functionality eliminates the need for separate dedicated components for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The stretch rod acts as an intermediary element that facilitates the removal of air and foam from the container. By inserting the stretch rod to create a passageway, it mediates between the closed sealed container and the external vacuum source, enabling controlled extraction without compromising the sealed environment.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Manufacturing precision

If vacuum is applied to remove air and foam, then manufacturing precision is improved through better fill level accuracy, but loss of energy increases due to vacuum maintenance

Engineering Contradiction:
Improvefill level accuracyVSAvoidvacuum maintenance
Core Design Contradiction:
Manufacturing precisionVSLoss of energy

Solution Approach 1:

The vacuum application is applied periodically rather than continuously - vacuum is applied to remove air and foam, then the seal pin is actuated to close the passageway, maintaining the vacuum state only when needed for fill level control. This periodic application reduces energy consumption while maintaining precision.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The air and foam are extracted from the container through the stretch rod passageway before the final vacuum sealing phase. By removing the bulk of air and foam beforehand, the vacuum system only needs to maintain a lower, less energy-intensive vacuum level during the final fill level adjustment, reducing overall energy consumption.

Inventive Principle:
Principle #2Taking out (Extraction)

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

Enables precise molding, accurate fill point adjustment, and effective removal of air and foam, improving fill control and preventing container collapse by maintaining atmospheric pressure within the container.

Implementation Method 1

trapping fluid and air within the container under pressure

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 2

Air, fluid, and/or foam is extracted out from within the container through a passageway defined within a stretch rod

Methodology Applied
Scientific EffectVacuum: Vacuum

Data Source

PatentEP3743259B1Foaming and fill level control through stretch rod
Publication Date: 2022.12.07 LIQUIFORM GRP LLC
  • EP3743259B1 patent drawingFigure 1~2
  • EP3743259B1 patent drawingFigure 3A~3F
  • EP3743259B1 patent drawingFigure 4

AI summary

Methods and systems for simultaneously forming and filling a container from a preform with fluid, adjusting a fill point of the fluid, and removing air and/or foam from within the container. One of the methods includes injecting fluid from a fill source into the preform through a nozzle passage defined between the nozzle and a seal pin of the forming and filling system to simultaneously form the container from the preform and fill the container. After the container is formed and filled, the seal pin is actuated to close the nozzle passage and prevent fluid and air from exiting the container through the nozzle passage, thereby trapping fluid and air within the container under pressure. Air, fluid, and/or foam is extracted out from within the container through a passageway defined within a stretch rod to adjust a fill point of the container.