Tank Sealing Closure with Locking Ring for Freeze-Drying

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Solution Overview

Problem

Existing sealing devices for fluid product reservoirs, such as pharmaceutical bottles, have limitations including small heat exchange surface area, risk of stopper popping out during freeze-drying, difficulty in applying coatings, use of metal parts leading to potential contamination and environmental issues, and complexity in manufacturing.

Innovation Solution

A sealing device comprising a cap, retaining ring, and locking cover with specific radial projections and deformable features, allowing increased heat exchange surface area, eliminating silicone and metal components, and ensuring secure assembly and sealing without crimping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of moving object

If a lateral cutout is made in the stopper to increase heat exchange surface area, then freeze-drying efficiency is improved, but the stopper may become inoperative in the closed position

Engineering Contradiction:
Improveheat exchange surface areaVSAvoidstopper sealing function
Core Design Contradiction:
Area of moving objectVSReliability

Solution Approach 1:

The stopper is segmented into multiple components: a main stopper body and a separate lateral wall portion that can be positioned in different configurations. This allows the lateral wall to provide heat exchange surface area while the main body maintains sealing capability when properly positioned in the closed state.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a two-dimensional cutout in the stopper to a three-dimensional lateral wall structure that extends radially. This dimensional change provides substantial heat exchange surface area while the wall's structural integrity and positioning mechanisms ensure the stopper remains functional when closed.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If silicone coating is applied to prevent stopper sticking, then transport and storage are improved, but coating application on the drug-contact side becomes difficult

Engineering Contradiction:
Improveanti-sticking propertyVSAvoidcoating application difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Different surfaces of the stopper assembly have different properties: the outer lateral wall and retaining ring surfaces are designed with anti-sticking characteristics through geometry and material selection, while the inner drug-contact surface of the cap remains smooth and coating-applicable. This localized differentiation allows silicone coating on external surfaces without interfering with internal coating application.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The retaining ring acts as an intermediary component between the stopper and the vial neck. It provides the anti-sticking function through its outer surface geometry and material properties, while allowing the cap's inner surface to be independently coated without interference. The retaining ring mediates the conflicting requirements by separating the functions of anti-sticking and drug-contact surfaces.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If a metal ring is used to secure the stopper, then sealing reliability is improved, but metal particles may contaminate the fluid and environmental impact increases

Engineering Contradiction:
Improvestopper securing strengthVSAvoidmetal particle contamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention replaces the metal crimping ring mechanical system with a plastic retaining ring that uses radial projections and lateral windows to secure the stopper. This substitution eliminates metal particle contamination risk while maintaining securing strength through alternative mechanical engagement mechanisms involving the vial neck geometry.

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

Solution Approach 2:

The retaining ring is made of plastic material that combines the necessary mechanical strength for securing the stopper with the chemical inertness and cleanliness required for pharmaceutical applications. This composite material approach replaces metal with a material that provides equivalent or superior performance in terms of both mechanical function and contamination prevention.

Inventive Principle:
Principle #40Composite materials

4Productivity

If the stopper structure includes a side cutout for heat exchange, then freeze-drying efficiency is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvefreeze-drying efficiencyVSAvoidstopper structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The stopper assembly is segmented into modular components (main stopper body, lateral wall portion, retaining ring) that can be manufactured separately using standard molding techniques and then assembled. This segmentation reduces the manufacturing complexity of each individual component while achieving the overall heat exchange function through the combined structure.

Inventive Principle:
Principle #1Segmentation

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 solution provides a larger heat exchange surface area, prevents stopper malfunction during freeze-drying, allows coating application, avoids metal contamination, and simplifies manufacturing, while being environmentally friendly and cost-effective.

Implementation Method 1

The said deformation profile includes a peripheral groove provided with a plurality of elastically deformable axial projections

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

each lateral window having a lower edge provided with at least one rigid lug extending radially inwards from said lower edge, said rigid lugs, in the sealing position of said retaining ring, being disposed under a neck of said tank

Methodology Applied
Scientific EffectMechanical fastening: Mechanical Fastener

Implementation Method 3

said upper wall of said blocking cover comprises flexible wall sections, separated by radial grooves

Methodology Applied
Scientific EffectFlexibility: Elasticity

Data Source

PatentEP4116216B1Device for sealing a tank of a liquid product
Publication Date: 2026.02.11 APTAR STELMI SAS
  • EP4116216B1 patent drawingFigure 1~6

AI summary

A closure device for a fluid product reservoir (10) having a neck (11), comprising: - a cap (1), - a retaining ring (20) for retaining said cap (1) on said neck (11), said retaining ring having a cylindrical structure (210) comprising wall portions (211) separated by lateral windows (212), each wall portion (211) having at least one internal radial projection (26) for retaining said cap (1) in said retaining ring (20), each lateral window (212) having a lower edge (212') having at least one rigid lug (21) extending radially inward from said lower edge (212'), said rigid lugs (21), in the closure position of said retaining ring (20), being disposed under a neck of said reservoir (10), thus securing said retaining ring (20) on said reservoir (10), - a locking cover (30) comprising a cylindrical wall (34) and an upper wall (35),said locking cap (30) being disposed around said fixing ring (20), to lock said fixing ring (20) in its closing position, the upper surface of said cap (1) having a deformation profile (12) which cooperates, after assembly, with said fixing ring (20).