Form, Cut, Stack: leading the trend towards thermoforming automation

Brian Golden, sales director, Americas, GN Thermoforming Equipment, shares how the medical packaging industry leads the trend towards thermoforming automation.

Automation of the thermoforming process has been embraced in the medical packaging industry more quickly than in other markets. Originally, this trend was driven by stringent quality requirements and the need for high levels of repeatability. Automation has also brought other benefits of strategic importance to medical packaging producers, including facilitating higher and more predictable throughput, as well as helping to address the challenges of attracting, training, and retaining a quality manufacturing workforce.

Strong flange and complex geometries

The shape of the packaging typically differs for medical products.

The entire package must withstand the temperature and pressure extremes of the sterilisation process. The flange must have the required thickness and rigidity, and smooth surface, to accept and maintain a hermetic seal to the Tyvek lid. The sidewalls must also have adequate and consistent strength and thickness to prevent cracking and leakage during transport and handling.

The most challenging aspect of medical packaging design is often the complex geometries required to isolate individual items into separate compartments and to lock each item in place. When properly designed and manufactured, undercuts allow each part to be snapped into place and held securely.

Elimination of airborne particulates

Most medical packaging applications call for enclosing the thermoforming machinery in a protective enclosure to minimise exposure to airborne particulates that can cause gaps during the hermetic sealing process.

It is imperative that measures are taken to eliminate static that will attract particulates and to ensure that the cutting process does not generate particulates that can migrate to the product.

Enclosing the machinery is important not only for protection against particulates but also for isolating the system from ambient air and temperature that cause fluctuations in the heating of materials and in the air pressure of pneumatic components.

Increasing automation

These various special requirements for medical packaging have led to the wide-scale adoption of Form/Cut/Stack thermoforming systems. Simpler and less costly Contact Heat systems are suitable for only a small fraction of medical packaging applications because they lack plug assist capabilities required for complex geometries and the higher clamping forces that Form/Cut/Stack systems offer.

Form/Cut/Stack systems are usually enclosed in a protective envelope protecting the process and the product from airborne particulates and ambient temperature and humidity, and they can be more fully automated and therefore more precisely monitored and controlled, especially machines with 100% servo motors and drives.

Investment in automation offers many advantages in medical packaging manufacturing - more precision and control result in much higher repeatability, which means higher quality products as well as fewer defects and less waste. The process improvements achieve faster cycle times and predictable output, for higher throughput and scalability.

Precise control and repeatability are also critical to the calibration and production consistency required by the strict standards and government regulations for medical packaging, such as ISO 11607:2019. Automation may also include vision systems and other inspection technology that provide automatic, continuous real-time quality control. In general, the more automation, the greater the opportunity to collect data for process improvement and for traceability.

Ease of operation

Instead of requiring one or more operators per production line, a single operator can cover multiple lines. First of all, this requires that the machines autonomously perform the forming, cutting, and stacking processes with little or no hands-on engagement by the operator. For high volume production, robotics are increasingly employed to automatically perform downstream packaging and palletising functions. But the autonomous operation of these functions is only one element of automation.

The procedures for changing tooling between SKUs and for replacing roll stock also need to minimise human error and effort. The right tooling needs to be installed in exactly the right way, for every production run, and roll stock can weigh 1500 lbs. Thermoforming equipment should be designed with procedures and tools for streamlining these processes and preventing errors and with ergonomic aids for lifting and correctly positioning heavy objects.

Looking forward

The whole concept of a Form/Cut/Stack thermoforming machine is to integrate and automate these multiple functions in a single system. Medical packaging manufacturers have been at the forefront of the trend toward automation, initially driven by the need for high quality, repeatability, and traceability. Automation also increased scalability and throughput. The third driver of automation is the need to address labour shortages and high turnover by making processes more productive and less labour-intensive, and easier to learn.