Absorbent Article Sterilization via Segmented Heat and Ozone

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Solution Overview

Problem

Existing methods for sterilizing absorbent articles, such as diapers and sanitary pads, face challenges in achieving effective sterilization while preserving superabsorbent polymer (SAP) integrity and safety, often resulting in incomplete sterilization and safety risks due to high ozone concentrations and excessive drying.

Innovation Solution

A method involving the separation of absorbent articles into smaller parts, followed by heat drying at 80°C to 200°C and direct application of gaseous ozone at concentrations between 960 ppm and 3000 ppm under dry conditions, providing both primary and secondary sterilization without altering the SAP structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high concentration ozone is used for sterilization, then sterilization effectiveness is improved, but safety risks and potential damage to SAP structure increase

Engineering Contradiction:
Improvesterilization effectivenessVSAvoidsafety risks and SAP structure damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the concentration parameter of ozone from high (traditional methods) to low (960-3000 ppm range), and adjusts the application method from direct high-concentration exposure to controlled low-concentration treatment. This parameter optimization achieves effective sterilization while preventing SAP structure damage and reducing safety risks

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent converts the potentially harmful high-concentration ozone into a beneficial low-concentration treatment. By using controlled low-concentration ozone, the harmful oxidizing effect is transformed into a gentle sterilization process that preserves SAP integrity while eliminating pathogens

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If excessive drying is applied to remove moisture, then sterilization is improved, but SAP integrity and future usability deteriorate

Engineering Contradiction:
Improvesterilization effectivenessVSAvoidSAP structure integrity
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent optimizes the drying temperature parameter, using moderate temperatures (80°C to 200°C) instead of excessive high temperatures. This controlled thermal treatment achieves sterilization while preserving the three-dimensional network structure of SAP particles

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies partial drying action rather than complete moisture removal. By controlling the drying process to achieve sufficient sterilization without over-drying, the SAP structure remains intact and suitable for future applications

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If absorbent articles are not separated into smaller parts, then processing simplicity is maintained, but sterilization effectiveness and material recovery decrease

Engineering Contradiction:
Improvesterilization effectivenessVSAvoidprocessing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides absorbent articles into smaller parts or particles before treatment. This segmentation increases the surface area to volume ratio, allowing ozone to penetrate more effectively and achieve better sterilization while facilitating subsequent material recovery and processing

Inventive Principle:
Principle #1Segmentation

4Productivity

If high temperature drying is used to remove moisture, then drying efficiency is improved, but energy consumption and SAP damage increase

Engineering Contradiction:
Improvedrying efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent optimizes the drying temperature parameter to a moderate range (80°C to 200°C) rather than using excessive high temperatures. This optimized temperature parameter achieves sufficient drying efficiency while reducing energy consumption and preventing SAP structure damage

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 method effectively sterilizes absorbent articles from pathogens like Escherichia Coli, Enterococcus faecalis, Staphylococcus aureus, and Candida albicans, allowing for the recovery of SAPs while minimizing safety risks and operational costs, and avoiding excessive drying.

Implementation Method 1

heating and drying the absorbent articles to a temperature of at least 80°C

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

directly applying ozone in gaseous state at a concentration of at least 960 ppm to the absorbent articles

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentEP3875120B1Method of sterilizing absorbent articles
Publication Date: 2023.09.13 ONTEX BV

AI summary

The present invention relates to a method of sterilizing used or un-used absorbent articles. It comprises the steps of providing said absorbent articles, separating said absorbent articles into smaller parts, heating and at least partially drying said absorbent articles at a temperature of at least 80°C to at most 200°C and directly applying ozone in gaseous state at concentrations of at least 960 ppm to at most 3000 ppm to said absorbent articles. The present invention advantageously relates to the recovery of raw materials from used or un-used absorbent articles that would otherwise be discarded for thermal processing.