Integrated Cap-Seal Assembly for Low-Force Medicament Access
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Solution Overview
Problem
Existing drug delivery systems face challenges in maintaining sterility and stability of liquid medicaments while requiring a robust, leak-free seal with the delivery device, often necessitating significant user force or multiple parts, and lacking features for permanent attachment of the outlet channel.
Innovation Solution
A co-moulded cap and seal system using a hard polymer cap and soft elastomer seal, designed for easy attachment and low-force access, with a thin septum barrier, guided insertion, and snap features for secure mounting, manufactured through various methods including additive manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a septum seal is used to create an air-tight seal, then sterility and seal integrity are maintained, but significant user force is required and sharp needles are needed for piercing
Solution Approach 1:
The cap is divided into two distinct functional parts: a hard cap structure and a soft seal component. The soft seal is inserted into the hard cap, creating a segmented system where each part performs its specialized function - the hard cap provides structural support while the soft seal provides compliance and sealing.
Solution Approach 2:
The invention changes the material parameter of the seal from rigid (traditional septum) to soft/compliant. The soft seal material can deform elastically to accommodate the outlet channel insertion without requiring significant force or sharp piercing, while still maintaining an air-tight seal.
2Reliability
If multiple parts (cap, seal, gaskets) are used to achieve an air-tight seal, then seal reliability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The invention merges the cap and seal into a single integrated assembly. The soft seal is inserted into the hard cap to form a unified component that performs both structural support and sealing functions, eliminating the need for separate gaskets and reducing the total number of parts.
Solution Approach 2:
The cap assembly uses composite construction with a hard cap material (e.g., polypropylene) and a soft seal material (e.g., silicone rubber or thermoplastic elastomer). This composite approach allows each material to contribute its optimal properties - rigidity from the hard cap and compliance from the soft seal.
3Reliability
If a thick septum is used to ensure seal integrity, then barrier properties are maintained, but piercing becomes more difficult and requires sharper needles or more force
Solution Approach 1:
The invention changes the physical state parameter of the seal from rigid to soft/compliant. The soft seal material can deform elastically during insertion, accommodating the outlet channel without requiring sharp piercing or excessive force, while still providing effective barrier properties against moisture and oxygen.
4Reliability
If a rigid material is used for the container to maintain barrier properties, then sterility and stability are maintained, but compliance with the outlet channel is reduced requiring larger compression forces
Solution Approach 1:
The invention applies local quality by making only the sealing portion of the cap soft and compliant, while the rest of the cap structure remains hard. This localized softness provides the necessary compliance for easy outlet channel insertion, while the hard structure maintains overall barrier properties and structural integrity.
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
Provides a cost-effective, leak-free, and user-friendly solution that maintains sterility and stability, allowing easy access to the contents without sharp needles and reducing manufacturing tolerances.
Implementation Method 1
the seal 2 should be made of a softer and pliable material, since it creates a tight seal by complying to an outlet channel's outside surface in use
Implementation Method 2
the region of the cap 1 around the seal 2 seating contains internal snap features 4 that keep the container 3 attached to the cap 1 in use
Data Source
Figure 1~2
Figure 3
Figure 4~6
AI summary
A cap and seal system for a liquid medicament container. The system comprises a cap formed from a substantially rigid material, and has a retention component integrally formed therewith. A seal is formed from a material which is less hard than the cap and positioned within the cap such that, when the retaining component retains the cap on a container in use the seal is positioned such that it forms a fluid tight seal between the cap and the container. A recess is formed in the seal through which a liquid outlet channel can pass in use to access the contents of the container via the cap and the seal.