Metal End Closure Threading for Resealable Twist-Off Containers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for sealing metallic containers are inconvenient, as they often require tools to open and cannot be resealed, leading to material inefficiencies and increased costs due to the need for thicker materials and complex capping apparatuses that require frequent maintenance.
Innovation Solution
A method and apparatus that form a thread on both the metallic container and end closure using a joining tool, allowing for a twist-off and resealable connection without the need for tools, using a thinner material for the end closure and reducing the thickness requirements of the container, thereby simplifying the capping process and reducing material usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a seamed-on end closure is used, then the container can be sealed, but it requires a tool to open and cannot be reclosed
Solution Approach 1:
The end closure is segmented into a first portion (closure body) and a second portion (peripheral curl) that are initially connected by scores but can be separated. The peripheral curl forms a tamper-evident band that breaks away during opening, allowing the closure body to be removed and reused while providing visual indication of opening status.
Solution Approach 2:
Scores are pre-formed in the end closure at specific locations before use. These scores create predetermined break lines that guide the separation of the peripheral curl from the closure body during opening, enabling easy manual opening without tools while maintaining security during transport.
2Ease of operation
If a tear panel with scores is used, then the container can be opened manually, but the end closure cannot be reclosed and requires thicker material
Solution Approach 1:
The end closure is divided into separable portions connected by scores. The peripheral curl (second portion) is designed to break away along the scores during opening, while the closure body (first portion) remains intact and can be reclosed. This segmentation eliminates the need for thick material throughout the entire closure structure.
Solution Approach 2:
Thicker material is used only in the closure body where structural integrity is needed for sealing and reclosing, while the peripheral curl uses thinner material since its function is primarily tamper indication. The scores create localized weak points that guide controlled separation without requiring overall thick construction.
3Adaptability or versatility
If a threaded closure system is used, then the container can be sealed and reclosed, but the container wall must be thicker and the capping apparatus is complex
Solution Approach 1:
The threading mechanism is extracted from the container wall and placed entirely on the end closure. The closure body includes integrated threads that engage with the container rim, eliminating the need for threaded holes or reinforced walls in the container itself. This reduces container wall thickness while maintaining reclosability.
Solution Approach 2:
The closure body acts as an intermediary component that provides the threading mechanism between the container rim and the sealing surface. Rather than modifying the container wall with threads, the closure body carries the threading function, allowing thin-walled containers to be used with reclosable metallic closures.
4Reliability
If a ROPP closure with thread roller is used, then threaded sealing is achieved, but the capping apparatus requires frequent calibration and maintenance
Solution Approach 1:
The closure body is pre-formed with integrated threads during the end closure manufacturing process, rather than requiring thread formation during capping. This self-contained threading eliminates the need for complex thread-rolling mechanisms in the capping apparatus, reducing calibration and maintenance requirements while maintaining reliable threaded engagement.
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
Enables easy opening and resealing of metallic containers without tools, reduces material thickness and operational costs, and minimizes damage during the sealing process, while maintaining the benefits of metallic containers such as impermeability and durability.
Implementation Method 1
a thread is simultaneously formed on both the metallic container and the metallic end closure
Data Source
AI summary
An apparatus includes a tool operable to releasably join a metallic end closure to a metallic container. In one embodiment, the tool is configured to form a thread in the closure and the container. The tool may optionally crimp the closure to the container. Once sealed, the container can be opened by rotating the closure in an opening direction. The closure can subsequently re-close the container by rotating the closure in a closing direction.