Despite their inherent disadvantages, including added expense due to
waste, labor-intensive installation, and inconsistent quality, manufacturers
have traditionally used die-cut or foam-tape gaskets for such applications as
waterproof seals surrounding automotive tail lights and hermetic seals enclosing
electrical equipment. Nordson Corp. has sidestepped these difficulties with the
development of equipment that produces closed-cell foam gaskets from a wide
range of pumpable sealants and caulks.
The equipment mixes the gasketing material with an inert gas that expands during dispensing, forming a resilient, reusable foam gasket. Nordson refers to this process as foam-in-place gasketing, or FIP.
Foam-in-place systems are more economical than conventional gasketing methods and provide more consistent quality and higher production rates. FIP can be used on existing assemblies to replace die-cut or tape-type gaskets, or in assemblies designed specifically for this gasketing method. It can provide a low-pressure air and water seal as well as protection from the environment.
The typical FIP system consists of an air-over-hydraulic piston pump configured to pump material from either a 5-gallon pail or a 55-gallon drum, a metering/mixing unit, a dispense head, and flexible hoses to connect the various components. The system can be engineered to operate at ambient or at elevated temperatures, depending on material characteristics.
The most cost-effective material for a gasketing application is one that meets, but does not exceed, performance needs. For example, a non-serviceable assembly at room temperature would not require an RTV. A hot melt material would suffice, at about half the cost.
To speak with a Nordson Corp.
applications engineer, call (216) 988-9411.