PHA Filter Segment for Aerosol Moisture and Biodegradability

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Solution Overview

Problem

Conventional aerosol-generating articles using cellulose acetate filters often result in 'dry' smoke due to high water absorption, leading to an undesirable smoking experience, and these filters are not biodegradable, posing sustainability issues.

Innovation Solution

The use of a filter segment comprising polyhydroxyalkanoate (PHA) fibers with a denier per filament between 1.5 and 2.7, which are more biodegradable and have a lower hydrophilicity, reducing water absorption and enhancing the smoking experience by maintaining higher moisture levels in the aerosol.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cellulose acetate filter material is used, then filtration efficiency is improved, but water absorption increases causing dry smoke

Engineering Contradiction:
Improvefiltration efficiencyVSAvoiddry smoke
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the material parameter from cellulose acetate to polyhydroxyalkanoate (PHA), which fundamentally alters the hydrophilicity parameter. PHA fibers have lower hydrophilicity than cellulose acetate, reducing water absorption while maintaining filtration efficiency, thus resolving the contradiction between filtration performance and smoke dryness

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite fiber structures where PHA fibers are combined with other materials to create a filter that maintains both filtration efficiency and reduced water absorption. The composite approach allows optimization of both parameters simultaneously

Inventive Principle:
Principle #40Composite materials

2Reliability

If cellulose acetate filter material is used, then filtration efficiency is improved, but biodegradability worsens

Engineering Contradiction:
Improvefiltration efficiencyVSAvoidbiodegradability
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the material composition parameter from non-biodegradable cellulose acetate to biodegradable polyhydroxyalkanoate (PHA). This parameter change simultaneously improves biodegradability while maintaining filtration efficiency, resolving the contradiction between performance and sustainability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs disposable filter segments made from PHA that are designed to be biodegradable after use. This approach aligns with the disposable nature of aerosol-generating articles while improving environmental sustainability through biodegradability

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Object-affected harmful factors

If PHA filter material is used, then biodegradability is improved, but water absorption decreases causing dry smoke

Engineering Contradiction:
ImprovebiodegradabilityVSAvoiddry smoke
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent optimizes the hydrophilicity parameter of PHA fibers by controlling fiber morphology, surface treatment, or composite formulation. This parameter optimization reduces excessive water absorption while maintaining the biodegradability advantage, resolving the contradiction between sustainability and smoke moisture

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

The PHA filter segment effectively reduces the 'dry smoke' issue by maintaining higher moisture levels in the aerosol and provides improved biodegradability, enhancing the sustainability of aerosol-generating articles while maintaining filtration efficiency and resistance to draw.

Implementation Method 1

which are more biodegradable and have a lower hydrophilicity, reducing water absorption

Methodology Applied
Scientific EffectHydrophilicity: Hydrophile

Data Source

PatentEP4069006B1Aerosol-generating article filter having novel filtration material
Publication Date: 2023.08.09 PHILIP MORRIS PRODUCTS SA
  • EP4069006B1 patent drawingFigure 1~2
  • EP4069006B1 patent drawingFigure 3~4
  • EP4069006B1 patent drawing

AI summary

An aerosol-generating article (10)(100)(310) comprises: an aerosol-generating substrate (12)(114)(312); and a filter (18)(122)(314) in axial alignment with the aerosol- generating substrate, the filter (18)(122)(314) comprising at least one filter segment (126)(318) of filtration material comprising a plurality of fibres comprising a polyhydroxyalkanoate compound, wherein the fibres have a denier per filament (dpf) of between 1.5 and 3.2 and wherein the at least one filter segment comprises at least about 20 percent by weight of the polyhydroxyalkanoate compound.