Hollow Bore Filter Element for Gentler Flavour Delivery

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Solution Overview

Problem

There is a need for improved design of Heat-Not-Burn (HNB) consumables to enhance user experience and function in smoking substitute systems, which aim to reduce health risks associated with traditional tobacco smoking by heating tobacco instead of burning it.

Innovation Solution

The design incorporates a flavoured filter element with a hollow bore, allowing for a gentler flavour delivery, and optional features such as upstream and terminal filter elements made of cellulose acetate tow, activated charcoal, or extruded plant material, with flavourants like menthol, liquorice, or tobacco, and an aerosol-forming substrate containing nicotine and humectants like propylene glycol, to enhance the vapour experience.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a solid filter element is used in HNB consumables, then the structure is simple and manufacturing is easy, but the flavour delivery is strong and may be too harsh for users

Engineering Contradiction:
Improveflavour delivery gentlenessVSAvoidfilter element structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent employs a hollow bore filter element with controlled porosity and internal structure. The hollow bore allows a portion of the vapour to pass through unflavoured while the outer surface provides flavourant contact, creating a gentler flavour delivery that resolves the contradiction between structural simplicity and operational gentleness.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The hollow bore acts as an intermediary structure between the flavourant source and the user's lungs. It allows selective vapour passage, mediating the flavour delivery to be gentler while maintaining structural integrity, thus resolving the contradiction between simplicity and operational characteristics.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If flavourant is applied to the entire filter element surface, then flavour delivery is maximized, but harmful compounds may be enhanced in the aerosol

Engineering Contradiction:
Improveharmful compound exposureVSAvoidflavourant quantity
Core Design Contradiction:
Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The patent applies flavourant locally to the outer surface of the hollow bore filter element rather than throughout the entire element. This localized application provides sufficient flavourant for pleasant vapour while avoiding excessive flavourant that could generate harmful compounds, thus resolving the contradiction between flavour quantity and harmful factor reduction.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention extracts the flavourant application from the entire filter element structure and concentrates it on the outer surface of the hollow bore. This extraction allows flavourant to be applied only where it contacts the vapour, maximizing flavour delivery while minimizing harmful compound generation from excessive flavourant.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If a hollow bore filter element is used, then flavour delivery is gentler and user experience is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveuser experienceVSAvoidfilter element manufacturing
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The hollow bore filter element utilizes controlled porosity and standard filtration material structures that can be manufactured using existing techniques. The hollow bore design provides gentler flavour delivery and improved user experience while remaining compatible with conventional manufacturing processes, thus resolving the contradiction between ease of operation and ease of manufacture.

Inventive Principle:
Principle #31Porous materials

4Quantity of substance

If flavourant is deposited on the filter element, then aerosol flavour is enhanced, but the filter element may become clogged with flavourant residue

Engineering Contradiction:
Improveflavourant concentration in aerosolVSAvoidfilter element performance consistency
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The hollow bore structure provides a controlled porous surface for flavourant deposition. The porous nature allows flavourant to be applied to the outer surface where it can be carried away by vapour flow, preventing clogging while maintaining consistent flavour delivery and reliability over time.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The hollow bore acts as an intermediary structure that separates the flavourant source from the vapour flow path. flavourant is applied to the outer surface which contacts the vapour, creating a mediator effect that enhances flavour without causing direct clogging of the internal vapour passage, thus maintaining reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution provides a modified taste vapour experience with a milder flavour hit and improved aerosol formation, enhancing user satisfaction while reducing harmful compound exposure, thus addressing the limitations of existing HNB systems.

Implementation Method 1

heat may be imparted to the tobacco material by a heating element of the device, wherein airflow through the tobacco material causes moisture in the tobacco material to be released as vapour

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

The vapour may contain nicotine and/or flavourings. In the HNB approach the intention is that the tobacco is heated but not burned, i.e. the tobacco does not undergo combustion

Methodology Applied
Scientific EffectSublimation: Sublimation

Implementation Method 3

As the vapour passes through the consumable (entrained in the airflow) from an inlet to a mouthpiece (outlet), the vapour cools and condenses to form an aerosol for inhalation by the user

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 4

The at least one hollow bore filter element may have a flavourant additive. The hollow bore allows some vapour to pass through unflavoured thus allowing a gentler 'hit' of flavourant

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 5

The released vapour may be entrained in the airflow drawn through the tobacco. As the vapour passes through the consumable (entrained in the airflow) from an inlet to a mouthpiece (outlet)

Methodology Applied
Scientific EffectAdvection: Advection

Data Source

PatentEP3873258B1Smoking substitute consumable
Publication Date: 2024.04.10 IMPERIAL TOBACCO LTD
  • EP3873258B1 patent drawingFigure 1
  • EP3873258B1 patent drawingFigure 2
  • EP3873258B1 patent drawingFigure 3

AI summary

The present disclosure relates to an aerosol-forming article (1) comprising an aerosol-forming substrate (2) and at least one hollow bore filter element (5) downstream from the aerosol-forming substrate. The at least one hollow bore filter element comprises a flavourant additive e.g. menthol.