Lightweight Container Neck Finish with Segmented Retaining Structure
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Solution Overview
Problem
Conventional tamper band closure systems require additional material and time to manufacture due to thicker retention structures, which are necessary for proper functioning but result in increased weight and longer production cycles, and often fail to ensure reliable tamper evidence upon initial removal.
Innovation Solution
A lightweight neck finish design incorporating a retaining structure with a frustoconical lower support portion and a circumferentially extending groove, along with a segmented thread and vertically extending slots, minimizes material usage and production time while ensuring proper engagement and breakage of frangible connections, enhancing tamper evidence visibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thicker retention structures are used to ensure proper tamper band engagement, then reliability of tamper band attachment is improved, but weight of the neck finish increases and manufacturing time increases
Solution Approach 1:
The retention structure features a frustoconical lower support portion with varying thickness - thicker at the base for structural support and thinner toward the top where the groove is located. This localized thickness variation provides sufficient engagement reliability for the tamper band while minimizing overall material usage and weight.
Solution Approach 2:
The retention structure is divided into distinct functional portions: a frustoconical lower support portion for structural integrity and a circumferentially extending groove for tamper band engagement. This segmentation allows each portion to be optimized independently - the support portion provides strength with minimal material while the groove provides reliable engagement.
2Reliability
If thicker retention structures are used to ensure proper tamper band engagement, then reliability of tamper band attachment is improved, but manufacturing time increases
Solution Approach 1:
The retention structure is formed as an integrated feature during the molding process, with the frustoconical lower support portion and circumferential groove created in a single manufacturing operation. This eliminates the need for separate machining or assembly steps, reducing manufacturing cycle time while maintaining reliable tamper band engagement.
Solution Approach 2:
The frustoconical geometry with its specific angle and dimensional parameters is optimized to provide sufficient structural support and engagement reliability while being manufacturable within standard molding cycle times. The parameters are selected to balance reliability requirements with manufacturing efficiency.
3Strength
If conventional retention structures are used, then adequate structural support is provided, but tamper evidence visibility is insufficient following closure removal
Solution Approach 1:
The circumferentially extending groove in the retention structure creates a visible discontinuity or gap that becomes apparent when the tamper band breaks during closure removal. This geometric feature enhances tamper evidence visibility by providing a clear visual indicator that the sealing integrity has been compromised, while the frustoconical support portion maintains the necessary structural strength.
Data Source
AI summary
A lightweight neck finish includes a retaining structure that interacts with a tamper band to cause frangible connectors between the tamper band and closure to break upon initial removal of the closure from the neck finish. An upper retention portion of the retaining structure has a profile with a reduced footprint as compared to a conventional retaining structure. A lower support portion of the retaining structure has an outermost diameter similar in size to an outermost diameter of a conventional retaining structure. However, the lower support of the lightweight neck finish is formed with one or more circumferentially extending slots and/or one or more vertical slots. The reduced footprint of the retention portion and the slots of the support portion minimize the amount of material, weight, and time and cost required to make the lightweight neck finish, while providing for increased tamper evidence visibility as compared to conventional neck finishes.