A SPECIAL SOLUTION WITH FUTURE POTENTIAL
MULTIVAC developed a packaging solution for dialysis bags for Laboratorios PiSA in Mexico. This development will also be able to be used in future for similar projects. Around 2.3 million people worldwide are affected by chronic renal failure. If they are unable to receive replacement organs, they require regular blood purification in the form of hemodialysis or peritoneal dialysis.
The task was clearly defined but very complex, as soon became apparent in the course of the project. As the contractual manufacturer to a supplier of medical products, Laboratorios PiSA had to produce dialysis bags with a sodium chloride solution and a volume of five litres, and it then had to pack these in secondary packaging. It was also necessary to reduce the quality problems with the previous packaging procedure, which had been carried out on chamber machines, as well as increasing the throughput by at least 25 percent. PiSA had just signed a contract for a higher production volume. The starting point for the challenge was therefore to optimise the packaging procedure and to switch this to a MULTIVAC thermoforming packaging machine, while maintaining the same pack properties. The packaging costs also had to be below the previous costs.
A challenging task
Up to that point, the secondary packaging for the dialysis bag had been a large film pouch which could be opened by means of a serrated cut. In order to produce a pack with the same properties on a thermoforming packaging machine, a new pack design had to be developed. The particular geometry of the pack provided a special challenge for MULTIVAC’s specialists. The requirement was for an individual pack with a high level of stability and a peel function, ensuring controlled opening could be achieved. The upper and lower webs had to be formed symmetrically and perfectly matched to the shape of the dialysis bag.
Several film suppliers failed during the course of the project due to the technical demands on the packaging material. It had to have high barrier properties, not remain adhered to the dialysis bag, be transparent and easy to form, as well as being suitable for subsequent steam sterilisation.
A perfectly suited packaging machine
The R 555 thermoforming packaging machine proved to be the optimum solution for the packaging procedure. This machine is equipped with an upper web forming station. This ensures that the upper web is firmly guided through the additional forming station and right up to the sealing station. “This means the film remains under tension and control during the entire procedure. This enables us to achieve a precisely formed upper web, a high level of process reliability and therefore very good pack quality,” explains Michael Theiss, Medical & Industrial Sales Director at MULTIVAC for Mexico and Central America. Following several test runs, the high-output machine was installed in Guadalajara.
The perimeter sealing ensures there is maximum seal seam strength and optimum peelable seal seams. “In the case of dialysis bags with a five litre content, the seal seam has to be very stable, but at the same time it has to be capable of being opened very easily. An additional opening slit, which also enables the pack to be opened easily, was added in case film without a peelable function was run. It proved possible to find a satisfactory solution for this requirement, as well“, says Michael Theiss.
In addition to this, the organisational and logistical requirements were by no means trivial. Large quantities of dialysis bags were sent to Germany for the sample productions and then back to Mexico, allowing various tests to be carried out and the samples sterilised before being checked. Today, MULTIVAC Mexico also supplies the packaging material, allowing Laboratorios PiSA to have a complete packaging solution from one source.
“Even if the effort was enormous, it is worth it for us in the long term to invest in such developments,” says Michael Theiss with confidence.
“The new technical knowledge gained will flow into other projects in the future. When it comes to similar types of dialysis bags, we can now offer, from the start, the same solutions, which include symmetrical forming of the upper and lower webs.”
Compared to the pouch pack used previously, significantly better pack quality and a greater number of packs are achieved today with the thermoforming packaging machine. And the cost per pack has also been substantially reduced.