The automotive industry was an early adopter of Form-in-Place gaskets (FIPGs) to replace conventional gaskets and o-rings, many applications being in the powertrain system. Historically, the most common uses were to prevent the ingress of dust, moisture and fluids. But an increasing number of manufacturers in new markets with many different requirements are transitioning to liquid gaskets and automated dispensing, because of the huge cost savings and increased productivity that can be achieved.
New applications for FIPGs are constantly emerging as the electronics and wireless industries grow, such as EMI and RFI Shielding in mobile phones and telecom devices, display panel support and light shielding in screen displays, acoustic vibration damping in handheld devices, navigation systems, optical equipment, thermal insulating or conducting in electronics and medical devices appliances.
Typically, precise beads of liquid gasketing material are directly dispensed to the surface of the part to be sealed; these beads are cured and bonded to the component for seamless sealing. FIP gaskets are a recognised, well proven, low-cost and high-speed cure alternative to manually applied O-rings or more expensive, complex pre-moulded or die cut gaskets. Techsil is one company that offers many Form-in-Place gasket solutions. Formulations include silicone liquids and pastes, flexible anaerobic gasket materials and UV and light curing gasket materials for an instant cure.
Selection of the correct sealant for use when making an FIPG is determined by both the method of production and the end application. The production methods will often dictate the properties of the sealant, either a paste or flowable product. Other physical features of the sealant, such as flow rate, viscosity and extrusion rate, can affect both production speeds and the choice or design of the automated dispensing system.
Environmental operating conditions are also important to consider. What is the gasket providing a seal against: chemicals, oil, fuels, moisture, water etc? Silicones have proven excellent in resisting harsh operating conditions and maintaining their physical properties, but some silicone sealants are better suited to certain conditions than others. Extreme operating temperatures can degrade many gasket materials; this will result in a loss of elasticity which in turn will lead to product failures.
Other physical and electrical properties may be important and also add functionality to the gasket. For example, silicone is naturally electrically insulating, but can be formulated to be electrically conductive. Thermal conductivity may be required to dissipate heat through the gasket into a heat sink or some other device. With many factors to consider, it is therefore important to involve your adhesive supplier early in the design process.