Container Sealing Defect Detection Using Pressurized Air Clearance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing container checking machines fail to accurately detect sealing defects in containers filled with highly viscous products, as the negative pressure test is obstructed by the product, leading to false positives due to membrane swelling and inability to clear obstructed holes.
Innovation Solution
A method using a combination of pressurization and depressurization cycles with a test head equipped with an LVDT sensor and air valves to measure membrane movement, where air under pressure is used to clear obstructed holes and detect defects, and a suction valve creates negative pressure to assess membrane integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If negative pressure test is used to detect sealing defects, then intact containers can be identified through membrane swelling, but containers with viscous products give false positives because the product obstructs the holes and prevents air extraction
Solution Approach 1:
The patent applies reverse logic by first pressurizing the test bell to force product out of obstructed holes, then switching to negative pressure to detect defects. This inversion of the usual sequence (negative pressure first) allows the system to clear obstructions before attempting defect detection, resolving the false positive problem with viscous products
Solution Approach 2:
The patent uses periodic alternation between positive pressure (pressurization phase) and negative pressure (depressurization phase) cycles. This periodic action allows the system to repeatedly clear obstructions and attempt detection, with each cycle increasing the likelihood of detecting actual defects while filtering out false positives caused by product obstruction
2Measurement precision
If air under pressure is applied to clear obstructed holes, then detection accuracy improves, but the system complexity increases due to additional valves and control mechanisms
Solution Approach 1:
The test bell is designed to perform multiple functions: it can apply both positive and negative pressure, clear obstructions, and detect defects. By making the same component multi-functional, the patent avoids adding separate dedicated mechanisms for each function, thereby limiting the increase in system complexity while still achieving hole clearance and accurate detection
Solution Approach 2:
The patent combines the pressurization and depressurization functions into a single integrated test head system with unified control. By merging these functions into one system rather than using separate independent systems, the patent reduces overall complexity while maintaining the ability to clear holes and detect defects effectively
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 effectively and precisely detects medium to small holes and large tears in the sealing membrane, ensuring accurate container inspection regardless of the product type, including viscous and semi-solid products, by using air pressure to clear obstructions and measure membrane movement within defined thresholds.
Implementation Method 1
a) feeding air under pressure into the test bell for a defined interval of time
Implementation Method 2
b) opening a suction valve connected to means for extracting air from the test bell in order to create in the test bell a predetermined negative pressure
Implementation Method 3
a detector, which internally mounts a sensor of the LVDT type, designed to detect the movement of the sealing membrane
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A method for checking the condition of containers (2) comprising a hollow body (5) for containing a semi-liquid or semi-solid product and a membrane (6) for closing the hollow body (5) comprises the steps of: closing the container (2) inside a test head (4) comprising a housing (10) to hold the container (2) and a cap (11) hermetically sealing the container (2) and defining an empty internal space (15); pressurising the space (15) inside the cap (11) by introduction of pressurised air inside the space (15), for a defined period of time (Ta); releasing the pressurised air from the space (15); measuring the movement of the membrane (6) due to the pressurisation of the space (15), by means of a position sensor (14); depressurising the space (15); measuring the movement of the membrane (6) due to the depressurisation of the space (15), using the position sensor (14).