Pre-tempering Blow Molds for Plastic Container Production

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Solution Overview

Problem

Conventional methods for forming plastic preforms into containers require significant energy to heat blow molds to operating temperature, leading to lengthy startup times and inefficient energy use, especially when all heating elements are used simultaneously.

Innovation Solution

The method involves pre-tempering blow molds when the machine is stationary, using a fixed or slowly rotating connection line to supply energy, and employing additional heating means to accelerate preheating, allowing for separate temperature control of blow mold components and maintaining operating temperature during operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If all heating elements are used simultaneously to heat blow molds to operating temperature, then the heating speed is maximized, but the energy consumption and power requirements become excessively high

Engineering Contradiction:
Improveheating speedVSAvoidenergy consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The heating process is segmented into two distinct phases: pre-tempering phase where heating elements are activated in sequences or groups rather than simultaneously, and operating phase where all elements work together. This segmentation allows controlled energy distribution while achieving the required heating speed over time.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A pre-tempering phase is introduced before full operation begins. During this preliminary action, heating elements are activated progressively to bring blow molds close to operating temperature, reducing the subsequent heating burden when full production starts.

Inventive Principle:
Principle #10Preliminary action

2Loss of time

If all heating elements are activated simultaneously, then operating temperature is reached faster, but the power supply infrastructure becomes overly complex and large

Engineering Contradiction:
Improvecommissioning timeVSAvoidpower supply infrastructure
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The power supply infrastructure is segmented into modular components that can be activated progressively. Instead of requiring all power lines and distribution systems to handle peak simultaneous loads, the segmented approach allows smaller, manageable power infrastructure that activates heating elements in controlled sequences.

Inventive Principle:
Principle #1Segmentation

3Productivity

If the machine operates continuously without stopping, then production efficiency is maintained, but the blow molds cannot be pre-tempered effectively

Engineering Contradiction:
Improveproduction efficiencyVSAvoidpre-tempering time
Core Design Contradiction:
ProductivityVSDuration of action of moving object

Solution Approach 1:

The pre-tempering action is performed as a preliminary step before continuous production begins. This initial preparation phase, though requiring machine stoppage or reduced speed, significantly reduces the heating burden during subsequent continuous operation, improving overall production efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The heating elements are activated periodically in sequences during the pre-tempering phase, with different groups of elements being activated at different times. This periodic activation pattern allows effective pre-tempering while managing power requirements.

Inventive Principle:
Principle #19Periodic action

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 reduces the time required to reach operating temperature, optimizes energy use, and enables quicker startup of the device, making it more energetically balanced and potentially smaller in design.

Implementation Method 1

the blow molds are heated with heating elements with a relatively high degree of energy

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a connecting line (18), in particular a fixed connecting line, is coupled to the device (1)

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3793803B1Method and device for shaping plastic pre-forms to form plastic containers involving the prior bringing to temperaturepreliminary temperature control of blow moulds
Publication Date: 2024.04.24 KRONES AG
  • EP3793803B1 patent drawingFigure 1~2
  • EP3793803B1 patent drawingFigure 3

AI summary

The invention relates to a method for operating a device (1) for shaping plastic pre-forms (10) to form plastic containers (20), wherein, in a working operation, a plurality of shaping stations (4) are moved along a predefined transport path by means of a moveable carrier (2), wherein these shaping stations (4) each have blow mould assemblies (6) which form respective hollow spaces in a close state, within which the plastic preforms are shaped to form the plastic containers and the plastic preforms (10) are supplied to these shaping stations (4) to be shaped into the plastic containers (20) by supplying a flowable medium, wherein this shaping occurs at least periodically during the transport of the shaping stations (4) along the transport path, and wherein at least components of the blow mould assembly (6) are brought to temperatureundergo a preliminary temperature control at least periodically. According to the invention, when the carrier (2) is at a standstill or when the carrier (2) is moving, at a slower pace relative to a movement of the carrier (2) in the working operation, a prior bringing to temperaturepreliminary temperature control of at least components of the blow mould (6) occurs.