By the end of April it had become clear that the ambu bag did not survive the endurance tests. By that time the bag had become the weakest link in an increasingly robust product.

As we were unable to source a silicone bellows of appropriate dimensions, work was started to manufacture an in-house design.

The bellows are manufactured with high-temperature silicone from Vosschemie, using injection molding in a polyurethane mold under vacuum.

The produced bellows have been tested to 2 million cycles without visible damage.

Our current production technology allows us to manufacture a small series. We have not yet found an industrial partner who is able to produce these in large volume.

Shore hardness50
Volume1,0 liter with current crank lever, can be extended
Wall thickness1,5mm
MaterialSilicone, endcaps PMMA

Injection molding is a technology well suited for large quantities, but has a significant startup cost.

As an alternative a 3D-printed version was made in TPU on a HP Fusionjet.
This model is significantly stiffer than the silicone version, to a shore hardness of 70.
It has been tested in a version2 machine to 1.5 million cycles and shows no wear.
This version needs more power to actuate. This test can be found here.

Grey 3D-printed bellows on the left, silicone injection molded version on the right

CAD-files for the bellows can be found on our downloads page.