Container Cap Sealing Inspection via Dye Injection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional methods for inspecting the sealing performance of container caps, particularly the inner seal, are inadequate as they do not accurately evaluate sealing performance when the outer seal is functional, leading to unnecessary costs and unreliable evaluations, especially when caps are newly designed or subjected to varying pressures and temperatures.

Innovation Solution

A method involving drilling holes in the cap to inject a dye into the sealed space, applying internal pressure, and checking for leakage to evaluate the sealing performance of both inner and outer seals, which can be done without specialized skills using an auxiliary apparatus that supports precise drilling and injection operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the conventional liquid leakage inspection method is used, then the sealing performance can be inspected, but the inner seal's sealing performance cannot be appropriately evaluated when the outer seal has sealing performance

Engineering Contradiction:
Improvesealing performance evaluation accuracyVSAvoidinner seal inspection reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The inspection method is segmented into three distinct injection steps: first injecting dye into the space between inner seal and outer seal, second injecting dye into the space between outer seal and mouth portion, and third injecting dye into the container interior. This segmentation allows independent evaluation of inner seal and outer seal performance, resolving the contradiction by enabling precise measurement of inner seal sealing even when outer seal is functional.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A dye is introduced as an intermediary substance to visualize and detect leakage paths. The dye serves as a mediator that reveals the sealing status of both inner and outer seals by showing where leakage occurs during the pressurization process, thereby improving measurement precision of sealing performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the electrical current detection method (Patent Document 1) is used, then leakage detection is possible, but all caps need to be made conductive or non-conductive incurring unnecessary cost

Engineering Contradiction:
Improveleakage detection capabilityVSAvoidcap manufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The inspection method uses a disposable dye solution instead of requiring permanent modifications to the cap structure. The dye is injected, used for detection, and then discarded, eliminating the need for expensive conductive or non-conductive cap modifications while maintaining effective leakage detection capability.

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

Solution Approach 2:

The electrical detection method is replaced with a mechanical/visual detection method using dye injection and pressurization. This substitution eliminates the need for electrical conductivity modifications to the cap while achieving equivalent or superior leakage detection through visual observation of dye leakage.

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

3Measurement precision

If the ultrasonic inspection method (Patent Document 2) is used, then sealing portion inspection is possible, but the neck portion must be cut excluding internal pressure influence

Engineering Contradiction:
Improvesealing portion inspection capabilityVSAvoidsealing performance evaluation reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The inspection is performed on完整地 sealed containers before any cutting or opening occurs. The dye injection and pressurization steps are conducted while the cap and seal structure remain intact, preserving the internal pressure conditions that exist in actual product storage and distribution, thereby ensuring reliable sealing performance evaluation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The inspection method controls and varies the internal pressure parameter during the test by applying different pressurization levels. This allows evaluation of sealing performance under different pressure conditions that simulate real-world scenarios, improving the reliability of the inspection results compared to constant atmospheric pressure ultrasonic inspection.

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 provides a reliable evaluation of the sealing performance of container caps under various conditions, including pressure changes and physical impacts, ensuring accurate assessment of both inner and outer seals without the need for costly cap redesigns or conductive materials.

Implementation Method 1

checking whether or not the dye leaks into the container

Methodology Applied
Scientific EffectLeakage:

Implementation Method 2

applying an internal pressure to the cap of the container into which the dye has been injected

Methodology Applied
Scientific EffectPressure: Pressure Increase

Data Source

PatentEP3165889B1Method for testing container sealing and assistance device
Publication Date: 2020.01.08 SUNTORY HLDG LTD
  • EP3165889B1 patent drawingFigure 1
  • EP3165889B1 patent drawingFigure 2
  • EP3165889B1 patent drawingFigure 3

AI summary

Provided is a highly reliable method for inspecting a sealing performance of a container and an auxiliary apparatus with which some of the steps of the inspection method can be executed without requiring skills. Provided is a method for inspecting a sealing performance of a mouth portion of a container and a cap including a resin outer seal and a resin inner seal that are formed on an inner surface of a top face portion, and the inspection method includes a first drilling step of forming, in the top face portion included in the cap screwed on the mouth portion of the container, a first hole that is in communication with a first space defined by a circumferential edge portion of the mouth portion and the inner seal and the outer seal, a first injecting step of injecting a dye into the first space, a first leaving step of leaving the container in which the dye has been injected into the first space, a first checking step of checking whether or not the dye leaks into the container in which the dye has been injected into the first space, and an evaluating step of evaluating sealing performance.