The collaboration with the Swiss medical technology specialist Ypsomed started in 2012. The company is a developer and manufacturer of injection and infusion systems for self-medication and a specialist for diabetes.
Peter Rohrer, sales engineer at Freudenberg Sealing Technologies in Switzerland, said: “When the project started, Ypsomed expected a much lower number of seals per year. We have now concluded a two-year purchase contract with a much higher order quantity.”
Challenge: High impermeability with minimal friction
Patients with type 1 diabetes depend on a constant supply of insulin. They can still lead an active and mobile life thanks to portable insulin pumps. The portable insulin pumps continuously deliver doses of the vital hormone into the body, keeping the patient’s metabolism in balance.
According to Freudenberg, the mylife YpsoPump from Ypsomed weighs 83 grams – including battery and full insulin cartridge – and is 16 millimetres high.
Freudenberg developed a dedicated rod seal for this purpose several years ago.
Patrick Kinsch, product developer in the fluid power industry lead centre at Freudenberg Sealing Technologies, said: “The challenge was to combine a high level of tightness with minimal friction.”
The reason: The pump is controlled on the basis of the patient’s blood glucose level, which is measured separately. The comparison between the target and actual levels follows various parameters that are determined inside the pump itself, mainly via a force measurement in the drive system. For reliable measurement – and thus precise control of the pump and insulin dosage – it is important to have as little friction as possible in the drive system.
To meet this challenge, Freudenberg has developed a suitable combination of a rod seal with a friction-optimised seal lip and surface; the specially matched lubricant is made by its affiliated company Klüber Lubrication. At the same time, a nanotechnology procedure lowers not only the roughness but also the friction of the elastomer. The seals with such treatment enable a consistent torque curve. Furthermore, the rod seal protects the system from contamination when the insulin cartridge is changed and seals the motor against leaking insulin in case the cartridge accidentally breaks.
“With this seal, we developed the optimum solution for the portable insulin pump from Ypsomed. We’re delighted that this is now reflected in a significantly increased purchase volume,” Rohrer added.
