Extruded rubber seals support complex cross-sections and a smooth surface finish. They include bulb, bulb trim, lip, door, and accordion seals. You’ll find all five types in Elasto Proxy’s catalog, along with many other rubber extrusions that are ready for custom fabrication.
Rubber profiles are made of elastomeric compounds and produced through molding or extrusion. Lengths of standard rubber products are then custom-fabricated to meet application requirements such as length. Rubber molding processes such as injection, compression, and transfer molding have their advantages, but extrusion supports the creation of rubber profiles with complex cross-sections and a smooth surface finish. As a custom fabricator, Elasto Proxy stocks extrusions made of solid rubber and sponge rubber, and can convert these standard products into specialty seals that meet your specific requirements.
Technical buyers and product designers who download our Extruded Rubber Products Catalog will learn that we keep hundreds of rubber extrusions in stock. The table of contents lists 19 different types of rubber extrusions, but there are five that are labeled specifically as “seals”. We provide plenty of other industrial sealing products too, but let’s focus on these five types of extruded rubber seals in this article. For industrial buyers and design engineers, it’s important to understand the basics of bulb seals, bulb trim seals, lip seals, door seals, and accordion seals. Let’s take a look.
Bulb seals have an open, rounded or teardrop-shaped area that gives these distinctive-looked rubber products their name. Some bulb seals feature other rounded shapes that resemble a half-moon, or have a flat bottom. Physical dimensions vary, but generally include height along with inner and outer diameter. Bulb gaskets are often made of sponge rubber, and installed between a door and door frame in a car or building. Softer bulbs made of materials such as EPDM foam help create a watertight seal. In automotive and construction applications, bulb seals may be attached by taping instead of mechanical fastening.
Bulb Trim Seals
Bulb trim seals are dual durometer seals with bulb and trim sections. Typically, the bulb portion is made of a medium-density sponge rubber such as EPDM. The trim or retainer portion of the bulb trim seal is made of another material, such as PVC. With their distinctive design and materials of construction, bulb trim seals can offer resistance to water, ozone, sunlight, and temperature extremes. These extruded rubber seals are also available in weather-resistant, reusable, and often recyclable materials called thermoplastic elastomers (TPEs).
Lip seals feature an edge or sealing lip and, in some cases, an opening. Often, they’re used to protect the bearing that supports a rotating shaft or bore. In addition to retaining the bearing’s lubricant, these rotary shaft seals help to prevent the ingress of dust and other contaminants. Radial lip seals are used in high-speed crankshaft applications for diesel and gasoline engines. They’re also used in other types of vehicles and with pumps, mills, and industrial equipment. Elastomeric compounds vary in terms of material properties, so make sure to select an oil-resistant rubber as required by your application.
Door seals are designed to fill the gaps between doors and door frames in order to prevent wind, water, and weather from entering vehicles or buildings. They’re used in cars, trucks, residential construction, and commercial and industrial facilities. Door seals such as hatch seals are also used with fuel tanks, electronic enclosures, and rooftop HVAC systems. This category of extruded rubber seals includes some types of bulb seals, but also includes custom weather stripping. Door seals are defined by their application rather than by geometric features or material composition, but are typically rectangular.
Accordion seals are extruded rubber products that have folds like the bellows of an accordion. Consequently, their physical dimensions are very different when stretched or compressed. Accordion boot seals are used to weatherproof access points such as between a truck cab and a trailer. Other types of accordion seals are also used in automotive and transportation-related applications. Materials of construction include EPDM rubber, and accordion seals may feature an internal spring steel loom.
How Can We Help You?
Do you have questions about bulb seals, bulb trim seals, lip seals, door seals, or accordion seals? Would you like to see drawings of these extruded rubber products, and learn about other rubber extrusions for industrial sealing? Let’s get started. Download the Extruded Rubber Products catalog today.
Thank you for reading this article from Elasto Proxy.
Clyde Sharpe General Manager at Elasto Proxy