Plastic Part Design f/ Sealing

[richg1]

Hi,

Does anyone know of a guide for designing plastic parts for sealed/sealing applications. In particular water resistance and water immersion.

I have a good handle on the design fundamentals of part design for sealing / gaskets etc but was wondering if there are any specific considerations for plastic parts.

Reason I ask is i am currently designing a plastic housing for a outdoor flow meter device. And am tossing up whether to utilise a face seal o-ring or alternatively a die-cut gasket as a copmression seal. Main concern with the latter is the potentially higher pre-load required to energise the seal over an o-ring. Although the o-ring may have a greater affect on the part design.

Any help much appreciated...Cheers Rich

 

[MikeHalloran]

Face seals, whether gasket or o-ring, require extra material and part depth to maintain preload between fasteners. Radial o-ring seals are less fussy in this regard, but may be harder to assemble.

Consider also formed in place gaskets, e.g. rtv silicone, which require no preload.




Mike Halloran
Pembroke Pines, FL, USA