Bringing Simplicity to the Packaging Process

Adopting an open automation architecture for the packaging line is one way of managing the complexity of packaging medical devices, where a variety of functions and sterility of contents are required. Examples of the benefits of this approach are described.

FEATURE

Packaging line flexibility

Isolated packaging solutions are of little benefit to the manufacturers of medical devices. What they need are complete packaging solutions, ideally from a single source, which satisfy the many requirements of a complex packaging process.

The variety of medical devices requiring packaging is vast, but they all have in common the need to meet the highest standards. For sterility, it is essential to match the packaging material and process with the chosen sterilisation method. Many medical devices are packed under clean room conditions, which means that the packaging machine or even the entire packaging line must be operated in accordance with the clean room class. Where requirements are especially high, it is advisable to isolate particle forming modules from their surroundings. To do this, the packaging line must have a flexible design so that the modules such as filters and air evacuation can be separated.

Packaging line flexibility is of course also important outside the clean room. To comply with packaging standards, the individual subprocesses must be continuously monitored from start to finish using visual inspection systems, sensors and individualised recording of process parameters. The careful calibration of critical measuring instruments on the packaging machine and the constant validation of the processes are important system specifications. However, the solution must not increase the complexity of the packaging line; instead it should reduce it. Reducing complexity increases process safety and lowers the cost of maintenance and training, which will be reflected in the overall running costs.

Open automation architecture

Modern packaging lines are characterised by an open architecture along the entire automation chain so that the line is suitable for the integration of different modules; for example, additional handling modules or labellers/direct printers can then be integrated depending on the package being produced. The objective of an open automation architecture is the avoidance of unnecessary functional complexity, for example, employing simple handling modules instead of oversized complex robots.

Application-specific developments allow the packaging line to be tailored accurately to the product needs. Given the large number of technically complex modules, solutions from a single source are advisable. This facilitates the integration of the modules into the control unit of the packaging line and there is only one entity responsible for integration and maintenance of the complete line.

Resource efficient processes

Some of today’s systems offer an economical and resource efficient way to package devices that need to be sterilised with ethylene oxide. Conventional packaging solutions use sterilisable paper or a polyethylene nonwoven fabric such as Tyvek (DuPont, http://www2.dupont.com/Tyvek/en_US/index.html [5]). In packaging processes where the material is fed in from a reel, the upper web is made entirely from high-grade Tyvek. However, there is no need to use such a large amount of Tyvek. Instead, it is sufficient for just a small area on the top of the packaged product to be permeable for ethylene oxide sterilisation. The process, which is integrated into the packaging line, uses a small piece of Tyvek positioned in a window left in the conventional upper web and sealed. Sensors detect the exact position of the Tyvek strip on the upper web.

This same process also offers an alternative to using a prefabricated pouch with a Tyvek insert. These pouches use an unnecessary quantity of material, partly because a substantial part of the pouch has to be trimmed off as an edge strip during the sealing process. The production of thermo-formed packs uses less material because only the top web of the thermoformed package will include a small window of Tyvek. This is a much smaller surface than the respective surface of a pouch; in addition, smaller production and storage areas are required.

Process simplification

Different packaging processes are also possible for products that have to be packaged twice such as surgical suturing material, cardiac catheters and operating room equipment. For these, two packaging machines can be connected in series and synchronised. One machine produces the first pack and transfer of this pack and insertion into the second pack, produced on the second machine, takes place automatically. During transfer, the packs are checked and defective packs are scrapped. An automatic system for removing samples can also be included in the line.

An open automation architecture approach as illustrated in this article soon demonstrates its advantages.

Information supplied by Multivac Sepp Haggenmueller GmbH & Co. KG, Bahnhofstrasse 4, D-87787 Wolfertschwenden, Germany, tel. +49 8334 6013 466, www.multivac.com [6]