Multiple Angles in Filled Eye Dropper Bottle Inspection
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A top pharmaceutical company seeking to upgrade its inspection of eye-dropper bottles implemented a solution using In-Sight 5400 vision sensors with Insight Explorer software by Cognex (Natick, MA), on two packaging lines.
The company sought a vision system for inspecting six styles of eyedropper bottles packaged at 250 per minute on two drop-dispenser lines. It required “total bottle inspection” of 100% of the product. The system verifies that each bottle is the correct style, measures liquid-fill levels and cap position, recognizes bottle deformities, and detects the presence of the eyedropper.
“The most challenging aspect of this application was dealing with the wobbling bottles. The liquid inside the bottles was not consistently oriented. Additionally, the bottles were shaking, causing bubbles to form at the liquid interface. And bottles can be angled up to 30 degrees at the time of inspection,” says John Jackiw, project manger at Automation Horizons Inc. (AHI; Chicago), the system integrator.
In the AHI/Cognex solution, one vision sensor is located after the capping station and before application of a tamper-evident plastic seal. As each bottle is screw-fed to a tabletop conveyor, the In-Sight 5400 sensor using an infrared light source captures images at up to 60 full frames per second. An on-board processor analyses the images employing five different software tools in a sequence of inspections. Objects can be defined and matched to images of correctly oriented product despite wide changes in angle, size, and appearance. If a bottle fails any inspection, a reject signal is sent to an Allen Bradley Micrologix PLC that triggers a reject mechanism to blow the part off the line.
In configuring an interface for the customer, AHI imported images and data from In-Sight Explorer into an AHI front-end interface, using the In-Sight Software Development Kit (SDK). Both AHI’s interface and SDK are written in Microsoft’s Visual Basic.net software (VB.NET) that supports camera network communications and links to SCADA and ERP systems.
“This customer wanted an interface that would allow them to easily add additional vision sensors in the future. By integrating the In-Sight software with our interface we are able to support an additional 10 vision sensors in the event the customer wants to add inspection stations,” says Jackiw.
During product changeovers, for example, operators could manage inspection job selection on multiple cameras when the next product type needs to run.
Using the SDK tools, AHI designed track-and-trace ability into the interface so that managers can know what changes were made, when, and who made them, for compliance with 21 CFR Part 11.
Engineers can use Cognex’s spreadsheet environment for configuring tools, but AHI’s interface restricts operators’ access to configuration tools and inspection code. Operators can perform tasks such as viewing live images and pass/fail statistics, selecting inspection jobs that correspond to bottle types and resizing search windows.
“You don’t have to have the Explorer software present. This locks down the software, limiting operators’ ability to manipulate tools, which is an important issue with pharmaceutical companies,” says Jackiw.
The system has enabled the company to reduce scrap and rework, and increase throughput. “The inspection data generated by the vision sensor allow them to find the root cause of specific rejects, which they keep track of in a database. This in turn allows them to continuously improve the process,” says Jackiw.