Eclipse Engineering has in-house capabilities to manufacture seals up to 55 inches in diameter, and over 100 inches through production partners.
While seals with huge diameters certainly grant their own significant levels of intricacy, here we’ll look at the other end of the spectrum: the micro-sized seals.
We won’t just look at a simple seal ring, but an inherently more complicated and geometrically detailed spring energized seal. As we’ll see, very small diameters make multiple manufacturing aspects more involved and challenging.
The Client’s Issue
A sealing solution in a customer’s epoxy dispensing equipment. They needed an effective seal for the reciprocating rod responsible for the flow-control and metering of the epoxy while being dispensed.
- Reciprocating Rod Seal
- Epoxy Dispensing Head
- Rod Diameter: 1.2mm [0.047”]
- Stroke Length: 6mm [0.236”]
- Cycle Rate: 15 per min
- Media: Epoxy
- Operating Pressure: 1,500 PSI
- Temperature: 70° to 150°F
In general terms, most viscous media sealing solutions have three things in common:
- A variant of UHMW for the seal jacket,
- heavy spring loading, and
- multiple point contacts with increased interference.
In most cases, multiple nested V-Springs are incorporated to provide optimal load and energize the compound contact points on the seal. With this formula, we’ve had great success sealing media like epoxy, urethane, silicones and acrylics.
The heavy loading is necessary to effectively wipe the reciprocating rod. This is balanced with the correct material and design geometry to provide long wear life of the seal, which has the potential to be compromised under such loading.
The challenge in this case was to incorporate these same proven principles in a micro-sized seal.