Syringe Seal Cap Sticking Prevention via Polyparaxylylene Coating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing seal caps for syringe needles tend to stick to the outer cylinder during storage and sterilization processes, such as high-pressure steam or ethylene oxide gas sterilization, due to direct contact and pressure loads, which can lead to removal issues and contamination risks.
Innovation Solution
A seal cap with a polyparaxylylene coating on the inner surface of the piercing needle mounting part and the outer surface of the outer cylinder, featuring a projected part and annular concave portion engagement, prevents sticking by maintaining close contact through the coating, ensuring easy removal and maintaining sterility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the seal cap is made to contact the outer cylinder directly for secure attachment, then the seal cap remains firmly fixed during use, but the seal cap sticks to the outer cylinder during storage and sterilization
Solution Approach 1:
The patent introduces an intermediate substance (polyparaxylylene coating or air layer) between the seal cap and outer cylinder. This intermediary prevents direct contact and sticking during sterilization while maintaining secure attachment during use, resolving the contradiction between reliable fixation and easy removal.
Solution Approach 2:
The patent changes the physical state or properties of the interface between seal cap and outer cylinder. By applying a polyparaxylylene coating, the surface properties are modified to prevent sticking while maintaining attachment, allowing the system to transition between secured and easily removable states as needed.
2Reliability
If the seal cap is sterilized with high-pressure steam or ethylene oxide gas, then sterility is achieved, but the seal cap sticks to the outer cylinder due to pressure load
Solution Approach 1:
The polyparaxylylene coating serves as a protective intermediary layer that prevents direct contact between the seal cap and outer cylinder during sterilization. This intermediary allows sterilization to proceed effectively while preventing the harmful sticking effect caused by pressure load.
Solution Approach 2:
The patent applies a polyparaxylylene coating beforehand to cushion against the harmful effects of sterilization pressure. This pre-applied protective layer prevents sticking before the sterilization process begins, allowing the seal cap to be easily removed after sterilization.
3Ease of operation
If the inner surface area of the seal cap is reduced for easy mounting, then mounting becomes easier and alignment is improved, but the seal cap may not remain securely attached during storage and transport
Solution Approach 1:
The polyparaxylylene coating acts as an intermediary that enhances the bonding between the seal cap and outer cylinder. This coating allows the seal cap to be easily mounted with reduced contact area while maintaining secure attachment during storage and transport through improved adhesion properties.
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 polyparaxylylene coating effectively prevents the seal cap from sticking to the outer cylinder, facilitating easy removal and maintaining sterility during sterilization, while ensuring the seal cap remains securely attached during use and storage.
Implementation Method 1
A seal cap with a polyparaxylylene coating on the inner surface of the piercing needle mounting part and the outer surface of the outer cylinder
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A syringe assembly (10) of the present invention is composed of an outer cylinder (2) and a seal cap (3). The outer cylinder (2) has an outer cylinder body part (21), a piercing needle mounting part (22), and a piercing needle (6) fixed to the piercing needle mounting part. The seal cap (3) has a closed distal end part (31), an open proximal end part (32), a piercing needle mounting part-accommodating part (35) accommodating a distal end portion of the piercing needle mounting part, a piercing needle accommodating part (34), and a pierceable part (33) into which the piercing needle tip is pierceable. A polyparaxylylene coating is provided on an inner surface of the piercing needle mounting part-accommodating part of the seal cap or on an outer surface of the piercing needle mounting part of the outer cylinder. The inner surface of the piercing needle mounting part-accommodating part of the seal cap and the outer surface of the piercing needle mounting part of the outer cylinder are kept in close contact with each other through the polyparaxylylene coating.