# Guidelines for selection of vacuum suction cups

- May 19, 2019-

Calculation of suction

The calculated attraction is only the theoretical value. In practical application, many important factors must be considered, such as the size and shape of the suction cup, the surface finish and hardness of the workpiece (deformation). Therefore, we recommend that the safety factor be at least twice as high.

The minimum safety factor required by German accident prevention regulations is 1.5 times. If the workpiece needs to be rotated or reversed, it is recommended to select a safety factor of 2.5 or higher to meet the force required in the reversal process.

Suction calculation formula of suction cup:

F = suction (no safety factor, pure static)

Δp = atmospheric pressure and pressure difference of vacuum system

A = Effective Adsorption Area (Effective Area in Vacuum State under Each Suction cup)

μ= Friction coefficient

The friction coefficient "μ" refers to the ratio of the friction force between two surfaces to the vertical force acting on one surface. Usually, the friction coefficient between the vacuum suction cup and the workpiece is not a fixed value, but must be determined by testing. The surface condition of the workpiece (rough/dry/wet/oiliness) or the attributes of the suction cup (structure/sealing lip/sealing ring/sucker material/Shore hardness) have a significant impact on the friction coefficient.

Lateral force is the force acting on the surface tangentially.

The measurements in the samples are in Newton units.

Suction cup compression stroke Z is a type variable produced by sucker during suction.

The working minimum curvature radius is the minimum radius of the workpiece that the suction cup can safely absorb.

Storage and cleaning of suction cup

In view of the susceptibility, storage and cleaning of sucker synthetic rubber materials, please note that:

The suction cup should be stored in a cool (0-15 C, up to 25 C), light-proof, dry, dust-free, ozone-free and pressure-free environment. Ozone, light (especially ultraviolet), heat, oxygen, moisture and mechanical external forces can shorten the life of suckers.

Use soap and warm water to clean the sucker and dry it at room temperature.