· Flat suction cups without cleats
Used for handling flat or slightly rounded, rigid, smooth objects. They withstand lateral forces and can be used for vertical handling.

· Flat suction cups with cleats
Used for handling thin, flexible, deformable objects. They increase resistance to lateral forces and horizontal handling.

· Suction cups with bellows
Used to handle spherical, cylindrical or egg-shaped objects. The effect of the technical characteristics increases with the number of bellows. They can be used for gripping objects with height differences, for a ball-joint effect, to lift and to grip corners or edges.

The force of a suction cup is proportional to its surface under vacuum and also depends on its shape, flexibility, material and especially on the level of vacuum attained inside the suction cup.

Theoretical force
. F(lbf) = (S (cm2 ) x V (%) x 0,01013) / 0.2248*
S = Surface of the suction cup (cm2 )
V = Vacuum level (%)
(*) coefficient to convert daN (decanewton) to lbf (pound-force)

Actual force
As its name implies, this force represents the actual force of the suction cup when in use. In general this is 50% less than the calculated theoretical force.
This difference is explained by the distortion of the suction cup during handling (which reduces the gripping surface), and by the condition of the surface of the object being handled.

The safety factor
All the forces are given in the tables for the various ranges of suction cup. These are actual values at 65% vacuum, calculated with a safety factor of:
. 2 for horizontal gripping (1),
. 4 for vertical gripping (2),
For applications involving high acceleration, the safety factor will be calculated accordingly.

To meet the constraints of industrial applications, COVAL has a wide range of both standard and specific materials. COVAL can also study new materials based on specific requirements of your applications.