Many kinds of manufacturing machinery make use of extruded rubber seals, particularly in manufacturing processes that involve fluids or pressurization. Machinery that is sensitive to environmental conditions or dust accumulation may also be shielded using some variety of rubber sealant, though some extruded rubber compositions can be damaged if exposed to certain chemicals or extreme temperatures. Rubber seals are an essential component in aerospace and marine applications where atmospheric stabilization or pressurization is necessary.
In consumer contexts, rubber seals can be found in swimming pool pump systems, garden hoses, bathrooms, kitchens, as insulation and weatherstripping and in many other applications. A rubber seal can be a film, gel, solid, putty or strip and will adhere to ceramics, glass, concrete, bricks, paper, other rubber materials, leather, textiles, metal, plastic, wood and many porous surfaces and composite materials.
Rubber is an elastometer and can be created from collecting natural materials and from artificial synthesis. In order to become usable, it must be processed. Like all rubber products, rubber seals are processed in some way. In some applications, as is the case with rubber trim, a machine or series of machines called rubber extruders will process the raw material so that it takes on a more appropriate shape or qualities for its application.
Extruded rubber is more useful as a temporary sealant as it can be placed and removed without damaging the sealant or the surface where it is applied. Examples of extruded rubber seals include weatherizing strips as well as plugs and stoppers. Non-extruded rubber sealants are used in contexts when a seal needs to be tailored to fit into, around or between surfaces. Such sealants are often manufactured, distributed and applied by the end-user as liquids or gels, and then they harden with time. Examples of applications for these varieties of sealant include caulking and waterproofing.
Neither extruded nor non-extruded rubber seals are designed to serve as permanent sealants. Re-application of non-extruded rubber seals is required at intervals as they are degraded by atmospheric conditions and as time passes. Extruded rubber seals, which are more frequently used in industrial settings, are subject to frequent or constant wear and also need to be replaced regularly. However, rubber seals are often an inexpensive sealant solution, and the cost of their occasional replacement is often much less than the cost of damages to the things they protect.