Conductive Innerseal Thermography for Sealing Defect Detection
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Solution Overview
Problem
Existing methods for detecting thermal sealing defects in containers, particularly those with cap liners and child resistance mechanisms, are inadequate as they fail to provide clear imaging of the sealing quality without damaging the product or causing false readings due to the cap liner's interference with infrared radiation.
Innovation Solution
A method utilizing a high-frequency heat induction unit to induce eddy currents in the conductive innerseal of containers, combined with a cooled infrared imager positioned above the container cap, which senses radiation within a specific wavelength range (2.0 μm to 6.0 μm) to generate IR image data and detect defects during transportation along a process line, ensuring the product remains undamaged.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional infrared thermography is used to detect sealing defects, then defect detection capability is provided, but the cap liner interferes with infrared radiation causing false readings or unclear imaging
Solution Approach 1:
The patent extracts the cap liner from the detection path by removing it temporarily during the thermography inspection process. This allows the infrared camera to directly image the sealing interface without the cap liner's interference, resolving the contradiction between defect detection accuracy and cap liner interference.
Solution Approach 2:
The patent performs preliminary heating of the sealing interface before thermography detection. By pre-heating the seal area, the temperature difference between defective and non-defective regions is enhanced, improving detection sensitivity and overcoming the cap liner's interference effects.
2Manufacturing precision
If high frequency heat induction is applied to the innerseal, then eddy currents are induced for heating and sealing, but overheating may damage the seal layer and protective barriers
Solution Approach 1:
The patent employs real-time temperature monitoring and feedback control during the high frequency heat induction process. The system continuously monitors the innerseal temperature and adjusts the induction power accordingly, ensuring optimal sealing temperature while preventing overheating damage to the seal layer and protective barriers.
Solution Approach 2:
The patent uses pulsed or periodic high frequency heating instead of continuous heating. This allows the heat to be applied in controlled intervals, enabling the seal layer to cool slightly between pulses and preventing cumulative overheating damage while still achieving effective sealing.
3Productivity
If rapid detection during transportation is implemented, then productivity is improved, but detection time window is reduced making accurate imaging difficult
Solution Approach 1:
The patent performs preliminary heating of the sealing interface before the container passes through the detection zone. This ensures that the temperature difference indicative of defects is already established when the container enters the sensing window, enabling accurate detection even during rapid transportation with limited sensing time.
Solution Approach 2:
The patent replaces complex mechanical synchronization systems with a stationary infrared camera positioned to capture images based on container position and speed. This simplifies the system while maintaining accurate detection during rapid transportation by using the container's own motion parameters for timing.
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 approach allows for accurate and rapid detection of thermal sealing defects, even with cap liners and child resistance mechanisms, without affecting the product, providing clear imaging and reliable defect identification, thus improving the quality control of sealed containers.
Implementation Method 1
induction causing eddy current in said conductive innerseal
Implementation Method 2
induction causing eddy current in said conductive innerseal
Implementation Method 3
sensing by said IR imager radiation emitted from said conductive innerseal
Data Source
AI summary
The present disclosure provides a method for detecting thermal sealing defects of a container during its transportation along a process line. The method is particularly suitable for containers caped with a cap liner and sealed with an inner seal. The method makes use of a high frequency heat (e.g. by a high frequency heat induction unit) to cause eddy current in the inner seal after which there is sensing by an IR imager of radiation emitted from the conductive innerseal to generate sensed IR image data indicative of the sensed radiation. The sensing is characterized by at least one of (i) a time window of a sensing session of between 50 msec to 300 msec during which said container is being transported through the FOV; and (ii) a sensing range of a wavelength spectrum region from 2 μm to 6 μm. The IR data is then processed so as to generate output data indicative of the presence or absence of at least one defect in the sealing of the container by said innerseal.