Polymeric Closure With Prying Projection For High-Temp Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional polymeric closures for high-temperature applications, such as retort processes, face issues with strong bonding between the closure and container, making it difficult to remove the closure after processing, and are not cost or environmentally friendly due to their three-piece design lacking chemical bonding between components.
Innovation Solution
A polymeric closure design featuring a polymeric top wall portion, liner, disc, and annular skirt with internal thread formations and a prying projection located near the top wall portion to assist in removal, allowing for effective separation from the container without chemical bonding, and optionally including a weakened area or oxygen-barrier layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If chemical bonding between polymeric surfaces is allowed to occur at high temperatures, then seal strength is improved, but closure removal difficulty increases
Solution Approach 1:
The closure is divided into multiple separable components: a closure body, a liner, and a disc. The disc acts as a sacrificial element that remains bonded to the container after the closure body is removed, allowing the main closure to be easily removed while maintaining seal integrity during processing.
Solution Approach 2:
The disc serves as an intermediary element between the closure body and the container. It provides the chemical bonding interface with the container while allowing the closure body to be separated, thus mediating between the need for strong sealing and easy removal.
2Ease of operation
If a three-piece traditional closure design is used, then ease of removal is improved, but manufacturing cost and environmental recyclability worsen
Solution Approach 1:
Multiple traditional closure components (closure body, liner, and disc) are merged into a single integrated polymeric structure. This maintains the functional benefits of the multi-component design while eliminating the complexity of assembly and improving manufacturability and recyclability.
3Reliability
If the closure is designed for robust sealing at high temperature, then seal reliability is improved, but removal torque increases
Solution Approach 1:
The sealing function is segmented between the liner (which provides the seal) and the disc (which provides the bonding interface). This allows the closure body to be easily removed by unscrewing from the liner, while the disc remains bonded to the container, reducing removal torque.
Solution Approach 2:
The disc is pre-positioned between the liner and container to establish the bonding interface before processing. This preliminary arrangement ensures that during high-temperature processing, the disc maintains the seal while being prepared for easy separation during removal.
Data Source
AI summary
A closure includes a polymeric top wall portion, a polymeric liner, a polymeric disc and a polymeric annular skirt portion. The polymeric disc is located between the polymeric top wall portion and the polymeric liner. The polymeric annular skirt portion depends from the polymeric top wall portion. The annular skirt portion includes: (1) an internal thread formation for mating engagement with an external thread formation of a container; and (2) an internal prying projection to assist in removing the closure from the container. At least a portion of the internal prying projection is located nearer the polymeric top wall portion than the internal thread formation.