Needle Protection Device Sealing Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing needle protection devices face challenges in ensuring reliable sealing, particularly with glass syringes, and can be difficult to manufacture and assemble, leading to risks of needle contamination and high production costs.
Innovation Solution
An injection device with a needle protection system featuring an inner body made of rubber with specific material properties (hardness > 55 Shore A, elasticity > 8 MPa, compression set < 30%, and density > 1.3) that securely seals the needle and is easy to manufacture and assemble, using a rigid outer body with a fixing part that cooperates with the syringe body and includes breakable material bridges for secure removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a deformable inner body is used to seal the needle distribution orifice and cooperate with the glass syringe body, then sealing is achieved, but manufacturing tolerances make it difficult to guarantee reliable sealing
Solution Approach 1:
The patent changes the material parameters of the inner body by specifying precise ranges for hardness (40-70 Shore A, preferably 50-65 Shore A), elasticity (5-15 MPa, preferably 7-12 MPa), and compression set (20-40%, preferably 25-35%). These controlled parameter changes ensure the material deforms sufficiently to seal around the needle while maintaining consistent sealing performance despite manufacturing tolerances in glass syringes.
Solution Approach 2:
The patent employs composite material properties by combining specific elastomeric materials with defined characteristics. The inner body uses elastomeric material that exhibits both deformability for sealing and dimensional stability, creating a composite functional material that addresses the sealing reliability issue through optimized material composition and properties.
2Ease of operation
If the needle protector is made easy to remove, then ease of operation is improved, but unwanted or accidental withdrawal before use cannot be prevented
Solution Approach 1:
The patent applies preliminary anti-action by designing the outer body with a fixing part that actively prevents unwanted withdrawal before use. The fixing part engages with the syringe body to create mechanical resistance against accidental removal, while still allowing intentional removal when needed. This preliminary protective action ensures the needle remains protected until proper use is initiated.
3Reliability
If a complex manufacturing process is used for the needle protector and outer body assembly, then sealing and fixing functions are achieved, but manufacture and assembly become complex and costly
Solution Approach 1:
The patent merges multiple functions into the inner body component. The same elastomeric material and structure provide both sealing of the needle distribution orifice and sealing cooperation with the glass syringe body. This functional merging reduces the number of separate components and assembly steps, thereby simplifying manufacturing and reducing costs while maintaining reliable sealing performance.
Solution Approach 2:
The inner body is designed with multi-functionality, serving as both the needle orifice seal and the syringe body seal. This universal component performs multiple sealing functions simultaneously, eliminating the need for separate sealing elements and reducing overall assembly complexity. The fixing part of the outer body similarly provides both mechanical fixation and structural support functions.
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 ensures reliable sealing, easy assembly, and prevents accidental withdrawal of the needle protector, reducing the risk of contamination and manufacturing complexity while maintaining dimensional stability under sterilization conditions.
Implementation Method 1
an elasticity greater than 8 MPa, in particular greater than 10 MPa
Implementation Method 2
a compression set less than 30%, in particular less than 25%
Data Source
AI summary
Injection device of fluid product (100) comprising a syringe body (101) and a needle (110) fixed in an axial end projection (102) of the syringe body, said end projection (102) comprising an axial end surface (103), said injection device comprising a needle protection device (200), said protection device being, in a storage position, fixed on said injection device, said protection device being removable from said injection device, said protection device comprising an inner body (210) made of substantially supple and/or deformable material and an outer body (220) made of substantially rigid material, said inner body (210), in a storage position, sealingly closing the distribution orifice (111) of said needle (110) and sealingly cooperating with said injection device (100), and said outer body (220) comprising a fixing part (228) which, in a storage position, cooperates with a shoulder (104) of said injection device (100) for fixing said protection device (200) on said injection device (100), said inner body (210) comprising a proximal axial end edge (213) adapted, in a storage position, to sealingly cooperate with the syringe body (101) only with said axial end surface (103), said inner body (210) being made of material having the following properties: a hardness greater than 55 Shore A, in particular greater than 60 Shore A, an elasticity greater than 8 MPa, in particular greater than 10 MPa, a compression set less than 30%, in particular less than 25%, a density greater than 1, in particular greater than 1.3.