Medical pouches – delivering quality on prescription

Photo | Bosch Rexroth AG
Marginal Column
Photo | Bosch Rexroth AG

The punches that separate the pouches after sealing use a Rexroth control unit and pneumatic system.

IndraDrive Mi reduces the wiring and installation costs.

Photo | Bosch Rexroth AG

Stacking table made of aluminum profiles.

Precise control is essential in medicine, and that starts right at the production phase. The American manufacturer CMD benefits from smart Rexroth technology.

 

From a simple trash bag with draw strap to packaging bags for the food industry, and on to special pouches for safe and sterile transport of medical and pharmaceutical products. At CMD, everything revolves around bags. The company based in Appleton, Wisconsin, USA, has been constructing and selling machines for these applications for over 30 years. The medical pouches are manufactured on the PDI Medical Combination Pouch System. The machine seals plastic film at a defined temperature, at precise pressure, and at matching dwell times. The stroke varies between 3 and 150 millimeters, and the machine can produce nearly 200 seals per minute. The system requires sophisticated technology and has to ensure precise process control in order to fulfill the stringent legal requirements in the pharmaceuticals industry.

Elaborate control made simple

In the manufacture of medical products, detailed documentation of all process steps is a must. At the same time, suppliers like CMD have to offer their customers convincing advantages to set them apart from the competition. In order to consistently ensure maximum quality in long production runs, real-time process monitoring and flexible management and controlling of all the decisive parameters in the sealing process – such as temperature, pressure and dwell time – play a major role.

An exceptional control system was therefore required for the new generation of the PDI Medical Combination Pouch System, with the capability to evaluate process data in real time and in doing so compile a specific “prescription” for each sealing process. This recipe-based programming ensures precise control of converting requirements each time a job is changed. On the basis of many years of experience, distributor partner, CMA/Floydyne/Hydradyne provided expertise and technical support to CMD when selecting controllers, motors and drives from Rexroth for this demanding project.

The IndraDrive Mi decentralized servo drives; for example, enormously reduce cabling costs, as only one cable is needed to connect all the integrated drives in a line. With the space-saving, compact KCU drive interface adaptation box from Rexroth, CMD was also able to benefit from a clear and simple control cabinet structure. Perfect synchronization of the individual production workflows – cutting and sealing of the pouches, for example – is provided by the motion logic system IndraMotion MLC with Flex Profile, which adds flexibility by dynamically adjusting all processing steps during conversion. Over and above this, Rexroth supplies the pneumatics for the cross coolers, along with runner blocks and profiled rails for cutting and sealing processes.

Flexible reactions – efficient production

At the Rexroth IndraControl VEP 40 HMI, the machine operator has everything at his fingertips. There, all the parameters can be reliably monitored and rapidly modified by touchscreen. If, for instance, the dwell time is a fraction of a second too short, that has an impact on the quality of the seal. As the software from Rexroth evaluates recipe data in real time, the operator can mark poor seals and immediately correct the settings for the next cycle – reducing material waste. “For our customers, that can mean the difference between throwing away a few pouches and losing an entire truckload,” says Scott Fuller, intermittent motion production line manager at CMD. The software also makes changeovers between jobs easy. Instead of replacing mechanical components, the operator quickly and easily makes those changes at the HMI terminal.

With this precise interplay of all the components, the PDI Medical Combination Pouch System completely fulfills CMD’s wishes and expectations. “The machine has everything: precision, high product throughput, and the ability to adjust everything immediately, using real-time data,” says Scott Fuller. “We are therefore in a position to supply a very high-performance machine – and that at a competitive price.”