The challenge
The packaging machine processes multiple bags per minute. After filling, the top of each bag is cut off and a transparent tape is heat-sealed. In practice, four types of sealing defects occurred: protruding seals, excessive visible seal, folds in the sealing area, and strings. Until now, seal integrity was manually assessed visually, requiring the continuous presence of an operator.
The objective was a system that performs this inspection fully automatically—without PLC interaction—and independently sounds an alarm or stops the machine upon detecting a deviation.
The solution
Vision Partners developed a turn-key packaging seal inspection system based on industrial machine vision. At its core is a high-resolution industrial camera that captures an image of the entire seal directly after it's been sealed. The image is taken against a red LED backlight, causing seal defects to stand out sharply in contrast against the background light. Image capture is triggered by a sensor on the outgoing conveyor belt, at the moment the bag is still upright—so that an operator can directly adjust the seal settings in case of an error notification.
The system consists of:
- High-resolution industrial camera with housing: captures the complete seal on every package
- Rode LED backlight: makes seal defects optically visible through contrast
- Industrial Machine Vision Computer (Intel / Windows IoT): processes the images and detects defects based on adjustable rejection parameters
- Touchscreen shows the operator real-time inspection results and log history
- Signal tower (visual and audible): warns the operator in case of a deviant seal
- 24V potential-free contact Automatically stop the machine upon detecting an error
The machine vision software analyzes the seal profile and recognizes the four defined error categories. Product engineers can set the rejection threshold themselves for each error type via the settings screen. The application supports multiple user levels—operator, product engineer, shift leader—and stores the inspection results in a log database.
The result
The packaging machine can now run autonomously without the permanent presence of an operator. Each seal is automatically inspected within the regular cycle time. In the event of a deviating seal, the operator is immediately alerted via the signal tower, and the machine can be automatically stopped via the digital output contact — all without PLC interaction.
Vision Partners delivered the system turn-key on-site, including installation, commissioning, and acceptance tests (FAT/SAT).
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