Non-destructive Seal Testing for Cigarette Packets

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Solution Overview

Problem

Existing methods for determining the seal of cigarette packets are either destructive, unsuitable for hard packets, or lack high accuracy, leading to issues like mildew, dry cracking, and aroma leakage.

Innovation Solution

A non-destructive method using Darcy's law, Fick's law of diffusion, and kinetic molecular theory to analyze pressure changes in an airtight chamber, providing indicators for effective air permeability, diffusion coefficient, and leakage area of the cigarette packet.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If inflation method is used to test seal, then detection capability is improved, but the method is destructive and cannot be applied to hard packets

Engineering Contradiction:
Improveseal detection capabilityVSAvoidapplicability to hard packets
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical inflation method with a pressure differential measurement system that uses sensors to detect pressure changes inside the packet without requiring physical inflation. This substitution allows non-destructive testing of hard packets while maintaining seal detection capability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a pressure sensor as an intermediary element that indirectly measures seal quality by detecting pressure changes within the packet, rather than directly inflating the packet. This intermediary approach enables non-destructive testing while preserving the packet for further use

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If punching and positioning method is used, then leak location can be identified, but the method is destructive and packets cannot be recycled

Engineering Contradiction:
Improveleak location identificationVSAvoidpacket recyclability
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent replaces mechanical punching and positioning with an electronic pressure sensing system that identifies leak locations through pressure differential measurements. This substitution eliminates physical damage to packets while maintaining the ability to locate leaks, enabling packet recycling

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a digital model of the packet's pressure distribution to identify leak locations, replacing the need for physical marking or punching. This virtual copying approach preserves the packet's integrity while providing precise leak location information

Inventive Principle:
Principle #26Copying

3Measurement precision

If constant flow rate evacuation is used, then pressure measurement can be performed, but the method may damage the packet film and affect measurement accuracy

Engineering Contradiction:
Improvepressure measurement capabilityVSAvoidpacket film damage
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies partial evacuation (reducing pressure to a controlled extent) rather than complete vacuum evacuation, achieving sufficient pressure differential for accurate measurement without subjecting the packet film to excessive stress that could cause damage

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent uses dynamic pressure adjustment and real-time monitoring to optimize the evacuation process, stopping before the packet film reaches its damage threshold while maintaining adequate pressure differential for accurate seal measurement

Inventive Principle:
Principle #15Dynamics

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 allows for non-destructive testing of cigarette packet seals, improving test accuracy and reducing sample preparation time, while providing physical indicators that reflect the seal quality.

Implementation Method 1

using a balance chamber to make the airtight chamber quickly form a stable negative pressure

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 2

Fick's law of diffusion of gas in the presence of a concentration gradient

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 3

By means of Darcy's law which reflects the basic law of pressure difference and flow velocity in porous media

Methodology Applied
Scientific EffectDarcy's law:

Data Source

PatentEP3985374B1Non-destructive testing method for sealing degree of small cigarette box packaging
Publication Date: 2025.04.16 ZHENGZHOU TOBACCO RES INST OF CNTC
  • EP3985374B1 patent drawingFigure 1~2
  • EP3985374B1 patent drawingFigure 3a~3b
  • EP3985374B1 patent drawingFigure 3c

AI summary

The application proposes a non-destructive testing method for the sealing degree of the small cigarette box packaging, which includes placing the small cigarette box to be tested in an airtight chamber, using a balance cabin to quickly form a stable negative pressure in the airtight chamber; The pressure change of the sealed chamber is continuously measured until equilibrium, and the data model is analyzed and established by using Darcy's law, Fick's diffusion law and the physical process of molecular kinetic theory. Through the non-destructive testing method for the sealing degree of the small cigarette box packaging of the present invention, the traditional destructive measurement (damaged small box packaging) for measuring the sealing degree of cigarette small box is changed into non-destructive testing; The test results have specific physical meaning; The test time of a single sample is reduced to 1/5 of the time of destructive test.