Rubber Seal Extrusions: Ensuring Perfect Sealing Solutions

From the doors of your car to the high-pressure environments of aerospace technology, rubber seal extrusions provide critical protection and insulation across numerous applications. They offer flexible but entirely supportive components that ensure air, water, dust, and other contaminants are kept at bay, maintaining the integrity and performance of countless systems and structures used daily.

Introduction to Rubber Seal Extrusions

Rubber extrusion seals are continuous profiles of rubber material that are produced through the extrusion process. They are designed to create a tight seal between two surfaces, preventing the passage of air, water, dust, and other contaminants. Rubber seals primarily provide sealing, vibration damping, insulation, soundproofing, and protection from environmental factors.

Materials

Rubber seal extrusions can be made from various types of rubber, each with specific properties:

The Extrusion Process for Rubber Seals

The extrusion process involves forcing rubber through a die to create continuous lengths of a specific cross-sectional profile.

1. Material preparation: the rubber compound is mixed and prepared.

2. Extrusion: the compound is fed into an extruder, heated, and forced through a die to form the desired shape.

3. Curing/vulcanisation: the extruded profile is cured to enhance its strength and elasticity. This is done through heat or chemical processes.

4. Cutting and finishing: the extruded rubber is cut to length and finished as required.

Profiles and Shapes

Rubber seal extrusions come in various profiles and shapes to suit different applications. Here’s a list of types of rubber seals:

• U-Channels

• D-Seals

• P-Seals

• T-Seals

• E-Seals

• Lip Seals

• Bulb Seals

• Custom Profiles

Standards and Specifications

Rubber seal extrusions often need to meet specific standards depending on the industry and application. These include:

UK-Specific Standards:

• BSI (British Standards Institution): The UK’s national standards body which provides standards for various rubber products.

  • BS 2751: specification for acrylonitrile-butadiene rubber (NBR) used in oil and fuel resistance applications.

  • BS 4443: methods of test for assessing the effects of liquids on vulcanised rubber.

  • BS 903: general physical testing methods for rubber.

  • BS EN 681-1: concerns elastomeric seals and material requirements for pipe joint seals used in water and drainage applications.

International and General Standards:

• ASTM Standards: various ASTM (American Society for Testing and Materials) standards for rubber properties. Examples include ASTM D2000 for rubber materials and ASTM D1149 for rubber deterioration.

• ISO Standards: international standards for rubber materials and products. Examples include ISO 3302 for tolerances and ISO 37 for tensile testing.

Industry-Specific Standards:

• OEM Specifications: original equipment manufacturer specifications for automotive and aerospace applications ensure that the rubber seal extrusions meet the manufacturers' precise requirements.

  • Automotive: OEM specifications from companies like Ford and Jaguar Land Rover often outline specific requirements for vehicle rubber seals.

  • Aerospace: OEM specifications from companies like Rolls-Royce and BAE Systems for rubber seals used in aircraft and aerospace components.

Applications in Various Industries

Rubber seal extrusions are vital components that hold the integrity of millions of different items together. In the automotive sector, these seals are essential for door seals, window seals, trunk seals, and weatherstripping. They ensure that vehicles remain airtight and protected from external elements, reduce noise, and improve energy efficiency.

In construction, rubber seal extrusions are important in effectively sealing windows and doors, preventing water ingress and air leaks in buildings. They are also used in expansion joints to accommodate structural movements and ensure the longevity of structures.

The marine industry relies heavily on rubber seal extrusions for hatch seals, porthole seals, and deck seals, where they protect against water ingress and harsh marine environments, enhancing the safety and durability of marine vessels. They’re also critical in the defence sector for similar purposes.

In the aerospace industry, rubber seals are indispensable for door, window, and panel seals. They maintain cabin pressure and protect against environmental factors at high altitudes.

Industrial applications of rubber seal extrusions include gaskets, vibration dampers, and protective barriers. These seals are used in machinery and equipment to prevent leaks, reduce vibrations, and protect sensitive components from contamination and damage.

Find out about different rubber extrusion seals in detail:

• Window seals

• Door seals

• Hatch seals

Benefits of Using Rubber Seal Extrusions

One of the primary advantages of rubber seal extrusions is their flexibility and durability. Rubber seals are inherently flexible, allowing them to withstand repeated deformation while maintaining their sealing properties. This resilience means they stand up to being bent and flexed, whether that’s installing them in awkward spaces or repeated movement over time as part of their application.

Another significant benefit of rubber seal extrusions is their weather resistance. Many rubber materials, such as EPDM and silicone, are highly resistant to environmental factors, including UV rays, ozone, and extreme temperatures. EPDM can withstand -50°C to +120°/150°C, and silicone can withstand -60°C up to +230°C. This makes them suitable for indoor and outdoor applications where exposure to harsh conditions is common.

Chemical resistance is also a key feature of certain rubber types, such as neoprene and nitrile. Nitrile can resist a range of acids, alkalis, and solvents, and neoprene can resist solvents, oils and petroleum-based fuel, among other substances. These materials are perfect for use in automotive, industrial, and aerospace applications where exposure to such chemicals is frequent.

Rubber seal extrusions have the significant advantage of being customisable. With custom profiles and materials, they can be tailored to meet specific application requirements. This ability to customise ensures that the seals provide the optimal performance needed for unique and demanding applications, enhancing their functionality and efficiency.

Customisation Options for Seal Extrusions

Custom-Made Rubber Seal Extrusions are tailored to meet specific requirements. The process starts with a detailed application analysis to determine the precise dimensions, shape, and material properties needed. A custom die is then created to produce the exact profile required. Custom seals are ideal for unique or highly specialised applications where standard seals would not suffice. They offer a perfect fit, enhanced performance, and specific properties like unique chemical resistance, flexibility, or hardness tailored to the operating environment. For example, a custom seal might be designed to fit an irregularly shaped groove in an aerospace component or to withstand extreme temperatures in a specialised industrial machine.

Standard Rubber Seal Extrusions, on the other hand, are pre-manufactured to common shapes and sizes, such as U-channels, D-seals, and P-seals. These can be mass-produced using standard dies and are readily available. They are suitable for general-purpose applications where precise specifications are not as critical or where the application is designed to meet generalised specifications. Standard seals offer cost-effectiveness and quicker availability compared to custom-made seals. They are often used in more routine applications, such as standard automotive door seals or basic window weatherstripping in construction.

Innovations and Future Trends in Rubber Sealing Technology

Smart Seals with Embedded Sensors

One noted innovation in rubber sealing technology is the development of smart seals with embedded sensors. The seals use advanced sensor technology to monitor real-time parameters such as pressure, temperature, and wear. The embedded sensors provide continuous feedback to support predictive maintenance and early detection of potential failures. By integrating these smart seals into systems, manufacturers can reduce downtime, optimise maintenance schedules, and improve safety and efficiency.

Freudenberg Sealing Technologies is a key player in this field. They have developed intelligent seals capable of monitoring their own state of wear and handling sensor applications. Their smart seals incorporate built-in functionality to act as sensors, providing data about their performance and safety, which helps prevent mechanical failures and unplanned downtime. One notable development is their intelligent rod seal, which forms a capacitor to measure wear and predict the seal's remaining service life.

Eco-Friendly and Sustainable Materials

Another emerging trend looks towards eco-friendly and sustainable materials in rubber sealing. With growing environmental concerns and regulatory pressures, the industry is developing seals made from biodegradable or recyclable rubber compounds. Innovations include the use of natural rubber sourced from sustainable plantations and the development of synthetic rubbers with reduced environmental impact. The core focus is on improving the life cycle of seals by enhancing their durability and resistance to degradation to reduce the frequency of replacements and waste production. These sustainable seals are increasingly being adopted in automotive, construction, and consumer goods industries, aligning with global sustainability and environmental conservation efforts.

Our blog uncovers everything you need to know about rubber extrusion products, from processes to custom designs to what we recommend for which applications. Take a look at our rubber extrusion blog or browse all the products we make to order.