Sterilizing Plastic Preform Outer Surfaces Using Turbulent Flow

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Solution Overview

Problem

Existing methods for sterilizing plastic preforms are inadequate in reducing germs on the outer surfaces, which can lead to recontamination and affect the shelf life of sensitive filling products, especially with insufficient disinfection rates for weakly acidic drinks.

Innovation Solution

A device that transports plastic preforms along a predetermined path, applying a flowable sterilization medium, such as hydrogen peroxide or peracetic acid, to the outer surfaces, with features like a rotatable carrier, adjustable application devices, and a flow generating system to create turbulent flow for enhanced disinfection, while also optionally sterilizing the inner surfaces using radiation or liquid media.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sterilization media are introduced into the interior of plastic containers, then the number of germs in the containers is reduced, but the consumption of sterilization media increases significantly

Engineering Contradiction:
Improvesterilization effectivenessVSAvoidsterilization media consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent applies sterilization media to the outer surface of preforms before they are blown into containers. This preliminary sterilization prevents germs from being incorporated during the blowing process, eliminating the need for subsequent internal sterilization of finished containers and reducing overall media consumption

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the outer surface of plastic preforms is sterilized, then the risk of recontamination during production is reduced, but the complexity of the sterilization device increases

Engineering Contradiction:
Improvesterile condition maintenanceVSAvoidsterilization device structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a flow generating device that creates turbulent flow of sterilization media over the outer surface of preforms. This turbulent flow acts as an intermediary mechanism that enhances sterilization effectiveness by preventing stagnant zones and ensuring uniform media distribution, thereby maintaining sterile conditions without requiring overly complex device structures

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If gaseous sterilization media are used for sterilization, then the sterilization process is simplified, but the disinfection rate on outer surfaces is insufficient for sensitive filling products

Engineering Contradiction:
Improvesterilization process simplicityVSAvoiddisinfection rate
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent employs a flow generating device that creates turbulent flow patterns using gaseous sterilization media. The turbulent flow enhances mass transfer and contact between the sterilization media and the outer surface of preforms, significantly improving disinfection rates while maintaining the simplicity of using gaseous media rather than requiring liquid application systems

Inventive Principle:
Principle #29Pneumatics and hydraulics

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

Improves the disinfection of outer surfaces, reducing germ contamination and maintaining sterile conditions during the production process, thereby extending the shelf life of filled containers by ensuring effective sterilization of both inner and outer surfaces.

Implementation Method 1

a flow generating device (6) which generates a flow of the free-flowing sterilization medium in the region of the transport path

Methodology Applied
Scientific EffectTurbulent flow: Turbulence

Implementation Method 2

a sterilization medium such as hydrogen peroxide or peracetic acid is introduced into the interior of the plastic containers

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentEP3330058A1Device and method for the sterilisation of the outside of plastic preforms
Publication Date: 2018.06.06 KRONES AG
  • EP3330058A1 patent drawingFigure 1~2
  • EP3330058A1 patent drawingFigure 3~4c
  • EP3330058A1 patent drawingFigure 4d~5

AI summary

Device (1) for sterilizing plastic containers (10) and in particular plastic preforms (10), comprising a transport device (2) which transports the plastic containers (10) along a predetermined transport path, and at least one application device (4) which applies a flowable medium to an outer surface of the plastic containers to be sterilized. According to the invention, the application device is arranged such that it applies the sterilization medium to a predetermined area of ​​the plastic containers (10) located below an opening of the plastic preforms.