This custom inflatable seals Q&A from Elasto Proxy explains what you need to know about a category of products that provide airtight and liquid-tight sealing for demanding applications.
What are inflatable seals?
Inflatable seals are flexible, hollow profiles that are filled, or inflated, to form an environmental seal. They are typically filled with air but are sometimes filled with nitrogen or other inert gases instead. The medium is delivered through a hose and then pressurized so that the seal expands.
What are they made of?
Inflatable seals are made of rubber compounds such as EPDM, which is good for outdoor use, or silicone, which can withstand higher temperatures. Butyl, nitrile, and other compounds are used as well. Viton is sometimes used for its enhanced resistance to chemicals and higher temperatures.
How do they provide airtight and liquid-tight sealing?
Inflatable seals are made of elastomers that are airtight and water-resistant. When inflated, the seal expands to press against the mating surface with a uniform and controlled force. This ensures that there aren’t any gaps where air or liquid could enter or escape.
Can they meet regulatory requirements or industry standards?
Yes. Inflatable seals can meet FDA requirements and USP Class VI standards – just to name a few.
How do they attach?
Inflatable seals can fit into a groove or use mechanical retainers such as clamps. They can also support the use of adhesives. For the best results, choose an attachment method that’s compatible with your larger product design.
How are inflatable seals different from other types of gaskets?
Most rubber gaskets rely upon compression rather than inflation. In other words, the gasket is compressed to fill a gap. Inflatable seals also fill gaps and provide sealing, but they are filled-up rather than pressed-down.
What are some advantages of inflatable seals?
Inflatable seals conform well to irregular surfaces, require low closure force, and provide dynamic sealing. This makes them a good choice for applications where surfaces are misaligned, there isn’t enough compressive fore, or there is relative movement between surfaces (e.g., a shaft and housing).
What are some key product specifications?
Seal profile is key because geometry affects how the seal inflates and contacts the mating surface. Inflation pressure is important because the pressure range must be matched to the seal’s design to prevent over-inflation or under-inflation. Inflation and deflation speed are worth considering as well.
What are some examples of custom inflatable seals?
Custom inflatable seals can inflate into a circle, square, rectangle, or straight line. They can also expand outward, inward, or radially. Products are available in specific shapes (profiles), sizes, colors, and compounds.
Can they handle high pressures?
Yes. Custom inflatable seals work well under low closure force, but they can also handle higher pressures. Often, Aramid reinforcements are used for these applications. Aramid fiber is a strong, lightweight, and heat-resistant fiber with an exceptional strength-to-weight ratio.
How are inflatable seals manufactured?
Inflatable seals can be molded, but they’re typically extruded instead. During the extrusion process, a rubber compound is forced through a metal tool called a die. The die’s shape determines the cross-section of the inflatable seal. Extrusion produces a length or coil that is ready for fabrication.
How are custom inflatable seals fabricated?
Elasto Proxy uses water jet cutting to convert coils into the lengths you need. For example, a 100-ft. (30.48 m) coil can be cut into 10 lengths that are each 10-ft. (3.048 m). The end joints are then bonded, typically with vulcanization but sometimes with cold bonding instead.
What is the minimum order quantity?
There isn’t one! Elasto Proxy welcomes small projects. This is part of what makes us different from other inflatable seal suppliers. We also differ in that we make inflatable seals for customer-specific projects and inspect what we fabricate for quality.
What are some applications for custom inflatable seals?
Custom inflatable seals are typically used in powder processing, agricultural, food and beverage manufacturing, and research and development applications. They’re also used in cleanrooms to maintain pressure differentials and with autoclaves or other pressure vessels.
Our next article will explain more. Until then, contact us for more information.
