The days when the surgeon instructed his assistants to sew the wound are largely over. Today - just like in the office - stapling. These surgical staples are usually made of titanium or stainless steel.

In our application for a US customer, the clips are made of titanium flat wire with a thickness of 0.21 mm and a width of 0.32 mm. The part weight is 0.005 g. The tip presents a particular challenge, as only a perfect tip ensures clean penetration into the skin. For this reason, the tips are not only cut, but also scraped in the opposite direction.

... the problem begins with the wire unwinding ...

Unwinding such filigree wire gauges is no longer feasible with standard wire unwinders. With a production output of over 400 surgical staples per minute, this results in a feed rate of an impressive 4.8 meters per minute. The high-precision, cam-controlled gripper feed EZ 60-80 from SBT ensures safe, yet gentle tape transport.

With a feed control angle of 120 °, this results in a feed speed of 14 m / s, whereby the wire must be held gently and without visible deformation. Despite the delicate task, extreme feed rates can be maintained.

Radial tool solution

Only a radial tool solution could be used to manufacture the clamps. The individual slides are driven on the radial module via a toothed ring, each slide has a pot curve with an external working curve and an internal curve for the forced return. All bending and cutting punches in the tool are made of hard metal (H40S).

The illustration shows the tool on the radial module and, for a size comparison, in one hand. The 100% ejection control is carried out via double light forks to detect the filigree parts. The removal of the tiny punching waste is particularly difficult; this is done safely with the SBT vacuum chip extractor VP-01.