Dwell Time Control for Glass Parison Mold Plunger

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Solution Overview

Problem

Existing glass container manufacturing processes face challenges in accurately controlling the dwell time of the plunger during the parison formation process, leading to suboptimal glass container quality and increased risk of mold opening due to overpressure, particularly when using multi-pressure systems.

Innovation Solution

A dwell time control method and system that uses three consecutive pressures to operate the plunger, with pressure switching times determined by analyzing the press curve from previous cycles to ensure optimal filling and prevent mold opening, allowing for automated pressure management without operator input.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multi-pressure systems are used to control plunger movement, then dwell time control precision is improved, but the risk of mold opening due to overpressure increases

Engineering Contradiction:
Improvedwell time control precisionVSAvoidmold opening risk
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The pressure control is segmented into multiple distinct pressure levels (first pressure, second pressure, third pressure) applied at different stages of plunger movement. The first pressure is applied during initial plunger movement, the second pressure during continued movement, and the third pressure during dwell time, allowing precise control at each stage while preventing overpressure that could cause mold opening.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts pressure levels based on plunger position and movement stage. Pressure switching is triggered by detecting specific characteristics of plunger movement (such as velocity changes or position thresholds), creating a dynamic control system that adapts pressure application to real-time conditions, thereby improving dwell time precision while maintaining safety margins against mold opening.

Inventive Principle:
Principle #15Dynamics

2Extent of automation

If automated pressure switching is implemented, then operator intervention is reduced, but system complexity increases

Engineering Contradiction:
Improvepressure switching automationVSAvoidcontrol system complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The system employs feedback mechanisms by monitoring plunger movement characteristics (position, velocity, acceleration) and using this information to automatically trigger pressure switching. Sensors detect movement characteristics and feed this data back to the control system, which then autonomously switches between pressure levels, achieving high automation through relatively simple feedback-based decision logic.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control system performs self-service by automatically determining when to switch pressures based on detected plunger movement characteristics. The system monitors its own operation state and autonomously adjusts pressure levels without external intervention, embedding the control intelligence within the existing press mechanism rather than adding complex external control infrastructure.

Inventive Principle:
Principle #25Self-service

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

The system effectively controls dwell time, automates pressure switching, prevents mold opening due to overpressure, and is durable, low-maintenance, and cost-effective, enhancing the quality and efficiency of glass container production.

Implementation Method 1

The plunger is raised to force the gob to fill the entire cavity defined by the blank mold halves, the neck ring halves, and the baffle, thereby forming the parison

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 2

The plunger was formerly driven by a hydraulic system

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 3

pneumatic systems using compressed air were adopted

Methodology Applied
Scientific EffectPneumatic pressure: Pressurisation

Data Source

PatentEP2570393B1Dwell time control method and system for a glassware forming machine
Publication Date: 2019.11.13 EMHART GLASS SA
  • EP2570393B1 patent drawingFigure 1
  • EP2570393B1 patent drawingFigure 2

AI summary

A dwell time control system and method are disclosed for automatically adjusting the selection and timing of a sequence of pressures (p1,p2,p3) used to drive the plunger in a parison mold during a parison forming process. The timing of characteristics of the observed press curve from one or more previous parison forming cycles are ascertained and used to control the timing (tp2, tp3) of the changes in pressure (p1 to p2, and p2 to p3) during a subsequent parison forming cycle. The timings of these changes of pressure are determined as predetermined percentages of the timings of the characteristics in order to prevent the parison mold from being forced open and in order to prevent the occurrence of an overpressed finish.