Segmented Screw Cap Core Seal for Even Neck Sealing
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Solution Overview
Problem
Existing screw cap designs face challenges in achieving reliable sealing performance against variations in container neck dimensions and tightening torques, leading to potential leakage and unreliable closure.
Innovation Solution
A screw cap design featuring an annular sealing element with a resilient backing and a facing layer, where axial compression causes radial expansion and upward rotation of segments, ensuring even distribution of sealing pressure across the container neck, and incorporating a detent for stable positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional sealing element is used in screw caps, then the structure is simple, but the sealing performance is unreliable against variations in container neck dimensions and tightening torques
Solution Approach 1:
The sealing element is divided into multiple axially extending segments that can independently rotate and expand. This segmentation allows each segment to adapt to local variations in the container neck surface, improving sealing reliability while maintaining a manageable structural complexity through modular design
Solution Approach 2:
The sealing element transitions from a static structure to a dynamic one where segments can rotate about their longitudinal axes and expand radially. This dynamic capability enables the seal to self-adjust to dimensional variations in the container neck and accommodate different tightening torques, resolving the contradiction between reliability and complexity
2Reliability
If the sealing element is made more compliant to accommodate neck variations, then sealing performance improves, but the structure becomes less stable under varying torques
Solution Approach 1:
Dividing the sealing element into separate segments provides both compliance for sealing and stability through controlled movement. Each segment can rotate and expand independently to accommodate neck variations while the overall segmented structure maintains stability under torque variations, preventing uncontrolled deformation
Solution Approach 2:
The sealing element's physical parameters (radial dimension, rotational position) can change in response to applied torque and neck variations. This parameter adaptability allows the seal to maintain stability across varying torque conditions while achieving reliable sealing through controlled dimensional changes
3Reliability
If the facing layer is made softer to seal against irregular surfaces, then sealing performance improves, but the facing layer becomes more susceptible to overstraining and extrusion
Solution Approach 1:
The segmented structure distributes mechanical stresses across multiple independent elements. The softer facing layer on each segment can conform to irregular surfaces for reliable sealing while the segmented configuration prevents stress concentration that would lead to overstraining and extrusion of the facing material
Solution Approach 2:
The facing layer's physical state changes dynamically under applied torque, allowing it to soften and deform into sealing engagement with the container neck surface. The segmented design ensures that parameter changes are distributed and controlled, preventing excessive deformation that would cause facing layer failure
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
The design provides enhanced sealing performance and fault tolerance against irregular neck surfaces and inaccurate torques, maintaining a secure closure even under varying conditions.
Implementation Method 1
a resiliently deformable seal energizing element comprising a central part braced against the cap body end wall and a peripheral part joined to the annular sealing element; the seal energizing element being constructed and operatively arranged within the cap body so that axial compression of the seal energizing element between central part and the peripheral part as the cap body is screwed onto the container neck causes radial expansion of the seal energizing element at the peripheral part, thereby radially expanding the annular sealing element towards the inner surface of the container neck
Implementation Method 2
the backing below this level comprises a plurality of separate, axially extending segments. With this arrangement, the axial compression of the seal energising element not only makes the peripheral part of the seal energizing element and adjacent part of the sealing element tend to expand radially, but also makes the axially extending segments tend to rotate upwardly and outwardly
Data Source
AI summary
A screw cap for containers comprises a screw cap body (10) and an expandable core seal (24) with an annular sealing element (30). A peripheral part (36) of a seal energizing clement (38) expands radially as the screw cap body (10) is screwed onto a container. The peripheral part (36) is joined to a backing (34) of the annular scaling element (30) which comprises a plurality of separate, axially extending segments (42, FIG. 4). The axial compression of the seal energising clement (38) thereby not only makes the adjacent part of the scaling element (30) tend to expand radially, but also makes the axially extending segments (42) tend to rotate upwardly and outwardly. A more evenly distributed sealing pressure of the annular sealing element (30) results.