Susceptor Defect Detection Using Microwave Heating and Infrared Imaging
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Solution Overview
Problem
Microwave food containers with defective susceptors can cause uneven heating, hot spots, or even fires during cooking, highlighting the need for a reliable quality check method to ensure susceptor integrity and consumer safety during manufacturing.
Innovation Solution
A method and apparatus that uses low-power microwave radiation to non-destructively test microwave containers as they move along a processing path, employing a resonator cavity and infrared imaging to detect temperature profiles and divert defective containers, ensuring only defect-free containers are shipped.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If high-power microwave radiation is used to heat susceptors for cooking, then heating effectiveness is improved, but defective susceptors can cause hot spots, burns, or fires
Solution Approach 1:
The patent performs quality inspection of susceptors before they are used in cooking. By exposing susceptors to low-power microwave radiation and measuring their temperature response, the system identifies defective susceptors (those with cuts, cracks, or gaps) before they can cause hot spots or fires during actual cooking, thus preventing harmful effects in advance
Solution Approach 2:
The patent converts the potentially harmful effect of microwave radiation into a beneficial inspection tool. By using low-power microwaves to heat susceptors and measuring temperature distribution, the system transforms what could be a dangerous heating process into a safe, controlled method for detecting susceptor defects
2Reliability
If quality testing is performed on every container, then product reliability is improved, but manufacturing complexity and time increase
Solution Approach 1:
The inspection system is integrated directly into the manufacturing line, allowing susceptors to be tested automatically as they move through production. The system uses the susceptor's own microwave heating properties to generate the test signal, eliminating the need for separate testing equipment or manual inspection processes
Solution Approach 2:
The patent implements continuous inspection of susceptors as they move along the manufacturing conveyor belt. The low-power microwave radiation and temperature measurement occur continuously during production, ensuring every susceptor is tested without interrupting the manufacturing flow or requiring batch processing
3Reliability
If low-power microwave radiation is used for inspection, then susceptor integrity is preserved, but detection sensitivity may be reduced
Solution Approach 1:
The patent optimizes the parameters of low-power microwave radiation (frequency, power level, exposure duration) to achieve sufficient temperature rise in defective susceptors for detection, while keeping the power low enough to prevent damage. The system measures temperature distribution patterns rather than absolute temperature values, allowing defect detection with minimal heating
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 solution allows for efficient, non-destructive quality testing of microwave containers at manufacturing line speeds, ensuring consistent and safe cooking performance by removing defective containers from the production line, thereby enhancing consumer safety and product reliability.
Implementation Method 1
A microwave source is coupled to the interior of the resonator cavity through a microwave horn antenna to establish a low power microwave environment within the resonator cavity. The containers are therefore exposed to low level microwave radiation as they move through the resonator cavity. This causes the susceptors of the containers to be heated
Implementation Method 2
The susceptors, which may be applied in many patterns, interact with microwave energy in a microwave oven to become hot
Implementation Method 3
The second microwave absorbing cavity includes an infrared window and an infrared imaging device or camera arranged to capture infrared images through the infrared window of containers passing through the second microwave absorbing cavity
Implementation Method 4
capture infrared images through the infrared window of containers passing through the second microwave absorbing cavity
Data Source
AI summary
A method and apparatus are disclosed for detecting defects in susceptors of microwave food containers during production of such containers. The method comprises the steps of advancing the microwave food containers in a downstream direction along a processing path; subjecting each microwave food container as it moves along the processing path to microwave radiation sufficient to heat the susceptors of the container without destroying the susceptors of the container; obtaining an image preferably in the infrared spectrum of the heated susceptors of each container; determining if the image is indicative of a defect in the susceptors of each container; and removing from the processing path containers that are indicated to have defective susceptors. The apparatus includes a conveyor that moves containers through a first microwave absorbing cavity, a resonator cavity wherein containers are subjected to microwave energy, and a second microwave absorbing cavity wherein an image of each container is obtained.