UV Absorbent Coating for Substrate Defect Detection
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Solution Overview
Problem
Current methods for inspecting sterile medical device packages are costly and unreliable due to human error and fail to effectively detect defects like pinholes in porous sheet components used in medical device packaging, such as TYVEK sheets.
Innovation Solution
A system using a UV absorbent layer applied to the substrate, combined with UV light and a UV-sensitive camera, detects defects by reflecting UV light, allowing for automated identification and rejection of substrates with openings greater than 10 microns, ensuring package integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If human inspectors conduct visual inspections of substrate components, then defects can be detected, but the inspection process becomes costly and unreliable due to human error
Solution Approach 1:
The patent replaces the mechanical/visual inspection system performed by human inspectors with an automated optical inspection system using UV light sources and UV-sensitive cameras. This substitution eliminates human error and fatigue while providing consistent, reliable defect detection across all substrates.
Solution Approach 2:
The patent utilizes the interaction between UV light and the substrate material to create visible contrast differences. Defects such as pinholes appear as dark spots against a lighter background when viewed under UV illumination, enabling automated detection through optical contrast rather than requiring human visual interpretation.
2Measurement precision
If traditional inspection methods are used, then the process is simple, but defects in porous sheet components like TYVEK sheets cannot be effectively detected
Solution Approach 1:
The patent changes the wavelength parameter of the inspection light to ultraviolet range. This parameter change enables the detection of defects in porous materials like TYVEK sheets that are invisible under visible light, as the UV light interacts differently with the porous structure and defect sites, providing enhanced measurement precision.
Solution Approach 2:
The patent introduces UV-sensitive cameras as an intermediary detection device that captures the optical contrast created by UV light interaction with the substrate. This intermediary converts the invisible UV defect patterns into visible images that can be analyzed with high precision, bridging the gap between UV illumination and defect visualization.
3Productivity
If automated inspection systems are implemented, then productivity increases, but the system complexity and initial cost increase
Solution Approach 1:
The patent designs a UV inspection system that can inspect multiple types of substrate materials (foils, porous sheets, TYVEK) using the same fundamental UV illumination and imaging approach. This universal method allows a single system to handle diverse materials, increasing productivity without requiring separate specialized inspection systems for each material type.
Solution Approach 2:
The inspection system is designed to operate autonomously without requiring human intervention during the inspection process. The UV light sources automatically illuminate substrates, the cameras capture images, and the system identifies defects through optical contrast, enabling continuous high-speed inspection that improves productivity while reducing operational complexity.
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
This method provides a reliable and cost-effective means to detect defects in medical device package substrates, enhancing the integrity of sterile medical device packages by automating the inspection process and preventing bacterial contamination.
Implementation Method 1
coating a substrate with a UV absorbent layer, and shining UV light onto or through the substrate having the UV absorbent coating
Implementation Method 2
detecting defects by reflecting UV light
Data Source
AI summary
A method of evaluating the integrity of a substrate used in medical device packaging include providing a flexible, porous substrate having a first major surface, and a second major surface, applying a UV absorbent layer over at least one of the first and second major surfaces of the substrate, and placing the substrate over a UV reflective surface. The method includes directing UV light toward the substrate and the UV reflective surface, whereby the UV absorbent layer absorbs light in a spectrum that matches the wavelength of the UV light, and detecting with a UV sensitive camera any UV light that is reflected from the first and second surfaces of the substrate. The substrate is rejected if the reflected UV light that is detected by the UV sensitive camera indicates that the substrate has at least one opening having a size that is greater than or equal to 10 microns. The substrate is accepted if the reflected UV light detected by the camera indicates that the substrate has no openings that are greater than or equal to 10 microns.