CVD Coating Inspection for Evacuated Vessels
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Solution Overview
Problem
Evacuated blood collection tubes and prefilled syringes face challenges in maintaining a substantial shelf life without increasing manufacturing costs, with issues related to vacuum retention, material leaching, and plunger movement consistency, while also needing to transition from glass to more durable and inert plastic materials.
Innovation Solution
A reflectometry method is employed to detect discontinuities in CVD coatings on vessels, using PECVD to deposit SiOx barrier coatings and hydrophobic layers, and inspecting for outgassing and permeation to ensure coating integrity, which helps in maintaining vacuum and preventing material interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If glass vessels are used for blood collection tubes and prefilled syringes, then gas tightness and chemical inertness are improved, but manufacturing cost increases and fragility becomes a problem
Solution Approach 1:
The patent applies composite materials by combining plastic substrate with thin film barrier coatings (such as silicon oxide, silicon nitride, or other impermeable layers). This composite structure provides the gas tightness and chemical inertness traditionally associated with glass, while maintaining the cost-effectiveness and durability of plastic. The barrier coating layer acts as the functional component that replicates glass properties, while the plastic substrate provides structural integrity and manufacturing advantages.
2Ease of manufacture
If plastic vessels are used instead of glass, then manufacturing cost decreases and durability improves, but gas tightness and chemical inertness worsen
Solution Approach 1:
The patent uses composite materials by depositing thin film barrier coatings on plastic substrates. The plastic provides cost-effectiveness and durability, while the barrier coating (such as silicon oxide or silicon nitride) provides the necessary gas tightness and chemical inertness. This composite approach allows the plastic vessel to achieve glass-like performance characteristics.
Solution Approach 2:
The patent applies local quality by providing barrier coatings specifically at critical locations where gas tightness and chemical inertness are most needed, such as the interior surface of the vessel that contacts the blood sample or pharmaceutical preparation. This targeted approach ensures that the plastic vessel achieves the necessary reliability properties at the interface with the contents, while maintaining the overall advantages of plastic construction.
3Reliability
If CVD coating is applied to plastic vessels, then coating integrity and barrier properties are improved, but detection of discontinuities becomes more difficult
Solution Approach 1:
The patent applies color changes by utilizing optical interference effects in the thin film barrier coating. When light reflects off the coating, constructive and destructive interference creates visible color patterns that indicate coating thickness and uniformity. Discontinuities or defects in the coating manifest as localized color variations or artifacts, making them visually detectable. This optical method provides a non-contact, rapid inspection technique for ensuring coating 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
The method effectively extends the shelf life of vessels by ensuring coating integrity, reducing material interaction, and ensuring consistent plunger movement, while allowing for the use of more durable and cost-effective plastic materials.
Implementation Method 1
plasma enhanced chemical vapour deposition apparatus for coating an interior surface of a vessel
Implementation Method 2
A thermoplastic vessel wall having an outside surface, an inside surface, and a CVD coating on at least one of the inside and outside surfaces. The vessel wall and the CVD coating have different indices of refraction so that energy is reflected from an interface between the vessel wall and the CVD coating
Data Source
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AI summary
A reflectometry method and other methods for detecting discontinuities in a chemical vapor deposition (CVD) coating are disclosed. The method includes several steps. A thermoplastic vessel wall (710) is provided having an outside surface, an inside surface, and a CVD coating on at least one of the inside and outside surfaces. The vessel wall and the CVD coating have different indices of refraction. Electromagnetic energy (718) is impinged on multiple positions of the CVD coating under conditions effective to cause energy to reflect from the multiple positions of the CVD coating. The reflected energy is analyzed to determine whether the reflected energy includes at least one artifact of a discontinuity in the CVD coating.