'Weeping' seals make sure IP66 switches don't stick
DP Seals has developed a novel 'weeping' O-ring solution for Bulgin
Components' new IP66 protected MP1 range of illuminated, vandal-proof
switches. The silicon nitrile seal is overdosed with low molecular weight
secondary silicon polymer, which leeches to the surface to provide
lubrication wherever it is needed. The result is a switch with
considerably extended service life.
The MP1 low profile switch is manufactured from marine grade stainless
steel and fitted with a tough polycarbonate lens; however, using ordinary
O-rings to seal the switch against the elements created a reliability
problem. Off-the-shelf translucent O-rings suffer from too wide a
tolerance variance and are often not de-flashed sufficiently, causing the
switches to stick. The DP seal lubricates the internal moving parts,
ensuring continuous, reliable operation well beyond the normal expected
life of the component.