Case Studies > Vision Systems for Syringe Inspections

Vision Systems for Syringe Inspections

The main objectives of the project were to provide vision systems to reliably inspect syringe body closure gap sizes, to aid in ensuring integrity of the product and to conduct label OCV inspection. The new vision systems designed, configured, installed and validated by Industrial Technology Systems Ltd’s engineers, have provided a means of inspecting the gap to a tolerance of 1/8 mm and the preprinted and overprinted information on the labels, before their application to the syringe. This information includes component placement verification, batch and expiry data and pharmacode recognition.

A major requirement of AstraZeneca was that the new vision systems installed were easy to operate and that the initial batch set-up process was simple, to reduce any potential problems that could arise.

The vision systems had to be fully validated by ITS' team and comprehensive training had to be provided.

The main objective was to improve performance through reductions in false rejects and to achieve 0% false passes. The new systems superseded older inspection systems, which used older technology and had fewer aids to fault diagnosis.

AstraZeneca has benefited from the following improvements that the systems have provided:

  • The gap closure inspection ensures that any syringe that is not closed to within 1/8 mm is rejected. This further ensures integrity of the product.

  • The systems are more tolerant to expected changes in light levels than previous vision systems which were used on these lines.

  • The systems are quickly set-up for a new batch. Operators simply select the required label number, enter the data for the overprinted text and press the ‘run’ button.

  • A major benefit is that optical character verification is now far more flexible. This means that the systems are capable of dealing with different font sizes and qualities of fonts. Operators have the ability to train the systems to accept text that is visually recognisable.

  • Label pharmacodes are automatically verified by the systems without any set-up required by the operator. The code is initialised when the label type is selected from a product selection pick-list.

  • Summary counters are maintained and displayed by the vision system user interface - reasons for label rejection are made obvious by each failure aspect/criterion having a counter associated with it. Further diagnostic information is obtained by the use of a ‘reject image browser’. This stores the last 20 reject images in the memory, and allows the operator to view them to see the cause of the product reject, for both labels and syringes. The vision systems are also capable of running and inspecting products whilst this is being done.

  • Each of the new vision systems are substantially more robust to changes in position of the label than earlier vision systems which were employed. The applications have been configured to ensure vertical or horizontal changes in the label position, (within limits), do not affect the reliability of the inspection. The systems also check the limits.

  • The reliability and accuracy of the vision systems have ensured that integrity continues to be maintained. The cost of downtime has reduced as the systems are more reliable and the process continues to run whilst rejected images are reviewed. Labour requirements have been minimised, as the operational aspects of the processes have been simplified. The number of false rejects has reduced resulting in cost savings.

The project involved the design, configuration, installation and testing of three vision inspection systems, responsible for inspecting labels and syringes on pharmaceutical packing lines. The systems were identical and were installed on separate lines.

Documentation was required to cover the functional, design, testing and operational phases of the projects.

Each system works by first acquiring an image of a label and determining a reference point on the label. The label pharmacode is then verified and two lines of overprint are checked against a match string entered at the start of a batch by the operator. If all aspects of the inspection are correct, the label is passed and applied to a syringe.

The second stage involves measuring the size of the gap between the body and chamber (part which contains the product), of the syringe. If the gap is larger than 1/8 mm the syringe is marked for rejection.

The results of both inspections are passed to the line PLC, which performs the product tracking, via fail-safe digital signals.

At site, ITS provided installation support, commissioning and validation services (IQ, and OQ testing). Full training was provided for operators and technicians.

All prescribed testing was successfully completed. Employees at AstraZeneca are delighted with the performance of the systems. As Len Brookhouse of AstraZeneca explained, “The performance of the vision inspection systems, installed by ITS, has far exceeded our expectations.” The interruptions to the manufacturing process both during and after the installations were minimal. AstraZeneca is so happy with the service delivery and the benefits that the project has delivered, that ITS has been awarded another project to carry out similar vision inspection projects on other production lines.


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