Pouch Sealer Upgrades De-Risk Validations

Recent improvements to the MS-451 integrated sealing and testing system allow for calibrations that complete machine verification.

Kassandra Kania, Freelance Writer

April 29, 2024

4 Min Read
 MS-451 medical impulse pouch sealer tester
Van der Stähl Scientific Inc.

At a Glance

  • Medical sealer incorporates a tensile/peel strength testing device and patented visual inspection system.
  • Critical parameters — time, temperature, and force — are calibrated and certified before the machine ships.
  • Instead of air valves to actuate the critical force at the platen, the sealer uses a direct-drive, custom-built solenoid.

As medical device packaging compliance becomes more rigorous, packaging machines will need to employ smarter systems that safeguard the medical pouch sealing process, says Charles Webb, founder and president of Van der Stähl Scientific Inc.

Webb is the inventor of the MS-451-PV, a medical device packaging system that incorporates a precision tensile/peel strength testing device and the company’s patented visual inspection system inside the pouch sealer.

In addition to integrating a peel tester and visual inspection tool at the point of packaging, the MS-451 prompts operators to perform testing and inspection on either a calendar prompt or number-of-pouches-sealed cadence. Additionally, the machine will not continue to package if seal strength falls below threshold values set by quality teams.

Calibration aids verification.

According to Webb, medical device manufacturers (MDMs) are creating validations on medical pouch sealers that use critical machine settings that cannot be calibrated.

“For medical device packaging validation, you need to understand time, temperature, and force of the packaging machine for your design of experiment,” he explains. “It is therefore vital that the machine components that create these attributes must be able to be calibrated.”

One of the recent upgrades to the MS-451 medical pouch sealer is that time, temperature, and force are now calibrated and certified before the machine ships from the company’s ISO-17025 calibration laboratory. Furthermore, the integrated tensile tester now has a load cell test spring, as well as a software algorithm, that quality teams can use to verify that the system is still operational within calibration tolerance. Webb shares that this is a significant upgrade because some tensile testing devices are falling out of calibration in between annual calibration events, and MDMs only discover this issue after thousands of devices are in the distribution chain.

Justin Anderson, president and CEO of Tensor Surgical, relies on the calibrated “smart spring” to verify the company’s MS-451, ensuring solid peel data that is recorded at the beginning and end of each batch lot. The sealer performs regular non-destructive and destructive pouch performance and tensile/peel testing in addition to sealing and visually inspecting pouches at the point of packaging. Anderson chose the MS-451 during the planning stages of his recently built ISO Class 5-certified cleanroom and sterile medical device packaging lab.

“I conducted extensive research to ensure that the pouch sealer I selected was as future-proof as possible technologically and that the company behind it can truly add long-term value to keeping our packaging program on track and in compliance — especially given the changes in EU MDR,” he says.

Tensor Surgical uses the side-lighting capability of the 3x-magnification visual inspection system to reveal possible integrity issues that may warrant future investigation, anomalies, as well as the smallest particulate in the sealed portion of the pouch. Inspection data is stored in the system’s onboard memory and used for operator training and performance monitoring as well as event archiving.

“Without the ability to perform these tests and visually inspect the seals at the point of packaging, the reality is that these important tasks aren’t typically — let along routinely — performed,” says Anderson. “This cannot only result in costly errors on a global scale but more significantly can compromise patient safety.”

Solenoid versus air-driven cylinders.

The MS-451 does not use air valves to actuate the critical force at the platen. Its direct-drive, custom-built solenoid is minutely controlled through the system’s advanced microprocessor.

“There is a temptation to use air-driven cylinders to create force for medical pouch sealers as it helps to drive down the cost; however, we believe there are too many issues with an air-operated system,” Webb says.

Air quality needs to be managed in the cleanroom and could be a source of contamination. But the bigger issue is validating the air supply that feeds the equipment. Webb says that to properly validate the air source, you need to alarm the airflow and precisely meter the air to be certain that your input air source has not changed and will not change. This can be a very challenging process.

“We use a robust electronic solenoid, and we can finely meter voltage to this electromechanical system to create precise and repeatable force at the sealing platen,” he explains. “The MS-451 medical pouch sealer’s solenoid-driven system also provides a cleaner and more straightforward installation qualification to begin your validation and only needs a standard 110-Volt outlet to operate.”


The case for standalone sealers.

Several automation companies have integrated Van der Stähl Scientific’s medical pouch sealers into their packaging lines. One such company successfully integrated multiple sealers into its line to package millions of nasopharyngeal swabs during COVID. But Webb says that standalone workstations have become more popular for medical device packaging.

“Rather than purchasing a monolithic and expensive packaging system, many device companies have moved to cellular workstations,” he says. “These workstations can be added as the company scales up, and they provide a great solution for the ebb and flow of production. Also, if a large, single medical pouch sealer goes offline due to a machine breakdown, production comes to a halt. With the individual workstation, packaging model production can continue.”

About the Author(s)

Kassandra Kania

Freelance Writer

Kassandra Kania is a freelance writer based in Charlotte, NC. She has written extensively about healthcare packaging for a variety of publications.

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