Why Seal Reliability Matters

When a seal loses its function, the consequences can be serious. Leaks may damage equipment, reduce energy efficiency, or even compromise safety in critical applications such as transportation, marine environments, or heavy machinery. The costs of emergency repairs and unscheduled downtime are usually much higher than investing in high-quality seals and proper maintenance from the start.

Common Causes of Seal Failure

Most sealing profiles fail for predictable reasons. By recognizing these issues early, it is possible to prevent them from shortening a product’s service life.

1. Incorrect material selection. Each environment places unique demands on seals. Exposure to extreme temperatures, aggressive chemicals, or continuous mechanical stress can cause premature failure if the material is not suited for the application.
   
2. Improper installation. Even the best seal will fail if installed incorrectly. Twisting, stretching, or damaging the profile during installation can create weak points that later lead to leaks.
   
3. Wear and tear. Over time, seals are exposed to friction, compression, and vibration. Without regular inspection and replacement, natural wear can progress unnoticed until performance is lost.
   
4. Environmental exposure. UV light, ozone, moisture, and salt can degrade some materials. Outdoor applications in particular require seals with high weather resistance.

Signs That a Seal May Be Failing

Maintenance teams can often spot early warning signs before a complete failure occurs. Stiffening, cracking, visible surface damage, or reduced elasticity are common indicators. Another signal is the need for repeated tightening of equipment or components, which often points to a seal losing its ability to maintain compression. Regular checks help detect these problems before they lead to larger breakdowns.

How to Extend the Service Life of Seals

While no seal lasts forever, careful planning and maintenance can make a significant difference. Companies can increase reliability and reduce lifecycle costs by focusing on a few essential practices:

• Choose the right material. Rubber, silicone, and TPE each perform best under different conditions. Considering temperature range, chemical exposure, and mechanical stress is critical to achieving a long-lasting result.
  
• Maintain regularly. Scheduled inspections, cleaning, and timely replacement prevent small issues from becoming costly failures. A proactive approach reduces downtime and keeps equipment running smoothly.

The Role of Design in Seal Durability

Material choice is only part of the equation. The design of the extrusion profile also affects how well a seal performs over time. Proper compression, tolerance, and shape all influence how effectively a profile maintains contact and prevents leakage. Working with an experienced manufacturer helps ensure that seals are tailored to both the mechanical and environmental requirements of the application.

Balancing Cost and Reliability

It can be tempting to save on material or installation costs, but cutting corners often leads to higher expenses later. A low-cost seal that fails prematurely may result in repeated replacements, lost production, and expensive repairs. In many industries, the total cost of ownership is much lower when seals are designed and maintained with long-term performance in mind.

Conclusion: Prevent Failure Before It Happens

Seal failure is rarely a sudden event. In most cases, it is the result of predictable issues such as poor material selection, incorrect installation, or neglect in maintenance. By understanding these causes and addressing them proactively, companies can extend the lifespan of their sealing solutions and avoid costly downtime.

The right material, the right design, and the right maintenance routine form the foundation for reliable sealing. At V.A.V. Group, we work with our customers to provide solutions that last, from material selection to custom design and long-term support. If you want to improve the reliability of your equipment and prevent seal failure, our experts are ready to help.

Artikkeli Understanding Seal Failure: Common Causes and How to Extend the Life of Your Sealing Solution julkaistiin ensimmäisen kerran V.A.V. Group.

MATERIALS USED IN PROFILE MANUFACTURING

Seal profile materials are designed and selected according to their intended use and operating conditions. V.A.V. Group makes its own raw material mix for seal profiles, which allows us to have complete control over the various properties of the profile, whether it is hardness, color, or other special features.
The primary materials used for profiles are silicone rubber, TPV (thermoplastic vulcanizate), and TPE (thermoplastic elastomer). These materials all have their functional properties, with some overlap in potential use cases. Silicone rubber has the broadest operating temperature range, and TPE and TPV profiles have excellent chemical resistance, which makes both well-suited for multi-component seals. Fire X is our self-extinguishing silicone profile that fits European standards for rolling stock, the maritime industry, and other sectors. It can also be used for doors and windows in other transport industries.

SILICONE RUBBER

What is silicone rubber?

Silicone rubber is a versatile, synthetic elastomer made from a polymer composed of silicon, oxygen, carbon, and hydrogen. It is widely used in various industries, including automotive, medical, and consumer goods, due to its stability over a wide temperature range and resistance to environmental factors. Its applications range from seals and gaskets to medical devices and kitchenware.

Silicone rubber is an excellent material for demanding conditions. We can adapt its properties to fit various operating environments; the properties of silicone rubber include resistance to steam, pressure, moisture, chemicals and oils, UV, and ozone. Silicone rubber has a superior operating temperature range, making it a perfect choice for almost any industry.

Properties of silicone rubber 

• Operating temperature of -80 °C – +250 °C
• Extruded hardness Shore A 10-80
• Tensile strength 200-1500 PSI
• Basic, metallic, and RAL chart -colors

Silicone rubber is commonly used for insulation in many industries and is an excellent electrical insulator. We also manufacture non-stretch silicone profiles, foam silicone, and self-adhesive seals, all of which have their own special advantages. Silicone rubber has an incredible range of applications.

Applications for silicone rubber

• Window and door seals
• Silicone tubing (including food-grade silicone)
• Pressure profiles
• Appliance seals
• Rings and gaskets
• HVAC tubing

Even though silicone as a raw material is not exactly recyclable, it has significant advantages, like its long service life, that still make it an ecological choice, especially when you get it from us. We at V.A.V. Group have the advantage of creating small to medium-sized batches, perfectly meeting the needs of manufacturers without risking leftover products going to waste.

FOAM SILICONE

What makes foam silicone different from our other profiles is its “spongy” closed cell silicone structure, which works almost like a foam mattress; it’s thick and sturdy and holds its shape well, making it especially great for example, insulating corners, where it provides support and keeps out the cold air and outside noise. Our foam silicone comes quite often as a co-extruded structure with two different grades of hardness: the soft, flexible, round, and insulating part and the harder “spine” that settles into the groove and makes installation easy while keeping the seal from stretching. We can also provide threaded foam silicone, which absolutely prevents the silicone from stretching.

The spongy structure of foam silicone makes it an excellent noise insulator, perfect for loud urban environments.

The properties of foam silicone aren’t too different from our other profiles, but there are some areas where it excels. Noise penetrates better than air and will slip through even the smallest of cracks, but foam silicone has exceptional noise-canceling properties. For example, proofing your front door or balcony doors with foam silicone can notably muffle outside noise, something that people living in big city apartments are all too familiar with. We recommend installing the foam silicone on the warmer doorcase side instead of the leaf for best results.

Foam silicone is still criminally unrecognized, even when it has the potential to be a real game-changer for insulation, as well as for noise-canceling in big cities and homes near highways.

FLUOROSILICONE

What is the difference between silicone and fluorosilicone? 

Silicone and fluorosilicone are elastomers made from oxygen, carbon, and hydrogen but differ in their polymer chains and properties. Silicone has a silicone polymer chain, while fluorosilicone includes fluorine atoms, changing some of its chemical and physical properties.

In summary, silicone is flexible and elongates well, while fluorosilicone is more heat and chemical-resistant, stronger, and more durable. The right material should be chosen based on these properties.

PLATINUM SILICONE

Platinum silicone or platinum-cured silicone uses, as you could guess from the name, a platinum-based catalyst to cure. The process results in a material that is free from any by-products like peroxides, which makes it safe for medical- or food-grade products. Platinum silicone has high thermal temperature, chemical resistance, and elasticity.

Due to its high purity and non-toxicity, platinum silicone can be used in medical devices, kitchenware, and baby products. It is also clearer than other silicone types and maintains this clarity without yellowing over time.

CHLORINE-FREE SILICONE

Chlorine – or halogen-free silicone profiles are produced by adding organic, chlorine-free peroxides to the silicone during its vulcanization instead of the traditional peroxide that has been used for decades in the silicone vulcanization process. Chlorine-free silicone can be used in all profile applications, from door and window gaskets to ventilation systems and many more.  

The benefits of chlorine-free properties are important, for example, in shipbuilding and rolling stock sectors, where silicone profiles work as a fire-safe insulator. One of the advantages of chlorine-free silicone is that should it be exposed to flames and burn; it will not produce harmful chlorine compounds or hydrochloric acid.

FIRE X SILICONE

Fire X profiles are made of self-extinguishing silicone that withstand temperatures up to 300°C. Not only does the Fire X withstand extremely high temperatures for long periods of time, but it is also fire-retardant and non-flammable in itself. 

In comparison to intumescent seals and profiles that expand when exposed to high temperatures, Fire X profiles are airtight in all temperatures. This prevents the spread of smoke, carbon monoxide, and other dangerous gases to other rooms or compartments before the temperature rises to a certain level. Since carbon monoxide can reach dangerous levels without an actual fire, Fire X seals are significantly safer than seals and profiles that only prevent the spreading of fires. Furthermore, if the compartments are sealed air-tight with Fire X profiles, they will significantly slow the spread of fire or even suffocate the flames in certain conditions. 

In normal conditions, the Fire X profiles act as normal silicone profiles, unlike intumescent seals that have little to no sealing capability without high temperatures.

Fire X is a silicone profile enhanced with fire-retardant and halogen-free materials. In short, the seals and profiles (along with other materials used in trains and their interiors) cannot ignite easily, burn aggressively at any point, or emit toxic fumes when predisposed to extreme heat. Fire X profiles are treated so that they will not burn but rather smolder and char even at the highest temperatures, maintaining their ability to prevent fires from spreading. This is a crucial feature for any profiles used in doors, windows, and latches on rolling stock.

Halogen-free profiles enhance the safety of railway passengers as well as firefighters sent to the scene, as they will not be exposed to toxic gases. Halogen gases are also highly corrosive, which may cause further damage to other components of the vehicle (or building).

The fire retardant Fire X profile ensures the safety of the crew and passengers and has the following fire safety certificates:

• IMO FTPC Part 2 & 5
• UL 94 V Classification V0
• EN 45545-2

Fire X and TPV can replace the commonly used EPDM, which can also be treated to withstand extreme temperatures. The advantages of Fire X, compared to EPDM, are a greater variety of hardnesses and colors, along with more manageable and often more reliable joints in angles or round shapes.

Main properties of different silicone compounds

Conventional silicone rubber

Silicone rubber is a very versatile synthetic elastomer. It is widely used in various industries, including automotive, medical, and consumer goods, due to its stability over a wide temperature range and resistance to environmental factors. Its applications range from seals and gaskets to medical devices and kitchenware.

• Heat resistance: Breaks down above 149°C
• Excellent flexibility and elongation
• Generally food-safe

Foam silicone

• Foam silicone has a its “spongy” closed cell silicone structure
• Great for insulating corners, windows and doors, where it provides support and keeps out the cold air and outside noise.
• Foam silicone is often co-extruded with harder surface protecting the softer inner material as well as often acting as a spine for installation purposes.

Fluorosilicone

• Heat resistance: Withstands up to 204°C
• Higher chemical resistance
• Lower flexibility and elongation but higher tensile strength and tear resistance. Longer lifespan, more stable, and less prone to swelling and shrinking compared to silicone

Platinum Silicone

• Heat resistance: Withstands up to 230°C
• Safe for medical- or food-grade products.
• High chemical resistance, and elasticity.
• Usually clearer than other silicone types and maintains this clarity without yellowing over time.

Chlorine-Free Silicone

• Chlorine-Free Silicone will not produce harmful chlorine compounds or hydrochloric acid when exposed to extreme temperatures (fire).

Fire X Silicone

• Self-extinguishing, non-flammable
• Operating temperature of up to 300°C
• IMO FTPC Part 2 & 5
• UL 94 V Classification V0
• EN 45545-2

TPE – THERMOPLASTIC ELASTOMER

What is TPE?

TPE is a class of materials that combines the properties of thermoplastics (like polyethylene and polypropylene) with elastomers (like rubber). TPEs are typically composed of a mixture of hard and soft segments, with the soft segments providing elasticity and the hard segments providing structural integrity.

TPE seals and profiles offer flexibility, resilience, and excellent sealing capabilities. They are softer and more elastic than PVC, making them suitable for applications requiring a tight seal and flexibility. The latest material developments have brought more rigid TPE materials to the market, thus closing the gap in this sector.

While a material like PVC typically has a higher melting point and is more suitable for high-temperature applications, TPE excels in low-temperature flexibility, ensuring effective sealing even in cold climates. TPE can also be treated to withstand very high temperatures, up to the point of being fireproof.

  Properties of TPE

• Excellent flexibility and elasticity
• Wide range of hardness options, from very soft to rigid
• Wide range of color options
• Moderate to excellent resistance to UV radiation and weathering, depending on the specific formulation
• Good chemical resistance can vary based on the TPE type
• Extremely versatile when it comes to thickness, shape, and size
• Hardness 40 Shore A – 45 Shore D
• Operating temperature of -40 – +120°C

TPE’s flexibility and elasticity make it ideal for applications where a secure and pliable seal is necessary. TPE seals are used in industries like automotive, where they are employed in weather-stripping and fenestration applications, providing an effective seal for doors and windows. The softness of TPE makes it suitable for areas where impact resistance and noise reduction are essential. 

    Applications for TPE

• Soft-touch grips and handles
• Overmolded parts and handles on tools and consumer products
• Automotive interior components, e.g. dashboard trim and cup holders
• Appliance seals
• Medical devices and equipment
• Cable and wire insulation

TPE materials are also known for their recyclability and environmental friendliness. TPE is often considered a more environmentally friendly option than materials like PVC and EPDM, as it can be reprocessed. While a material like PVC is generally more cost-effective than TPE, TPE’s superior performance and environmental considerations may justify its higher initial cost in specific applications. Thanks to its recyclability, TPE can become more cost-effective than PVC when considering disposal costs.

Due to its recyclability, TPE can be more cost-effective than other alternatives, like PVC.

TPV – THERMOPLASTIC VULCANIZATES

Thermoplastic vulcanizates (TPV) are part of the thermoplastic elastomer (TPE) family of polymers but are closest in elastomeric properties to EPDM thermoset rubber, combining the characteristics of vulcanized rubber with the processing properties of thermoplastics. Like TPE, TPV is recyclable and has good UV, ozone, and chemical resistance, and in some cases, even greater resistance than EPDM. 

What is the difference between TPE and TPV?

TPE is a mixture of rubber and plastic that can stretch under stress but snaps back into shape afterwards.TPV includes a blend of EPDM rubber and polypropylene which, when vulcanized, makes it highly resistant to heat and compression.

Our selection includes combinations of foam and hard TPV. Our TPV material has been tested accordingly for EN45545-2 R22/23 HL2.

Applications for TPV are much the same as those for TPE.

♻ BIO-TPE

Our selection also includes Bio-TPE, in which 65 % of fossil materials have been replaced with bio-based oils, making it an ecological alternative for TPE. Like TPE, Bio-TPE is a fully recyclable material with the same features as TPE. 

Like regular TPE, Bio-TPE is a fully recyclable, non-toxic material, and it has the same excellent chemical resistances and hardness of 50-90 ShA in a full RAL color scale.

PVC, EPDM, OR TPE?

In this section, we have shared some basic information about PVC and EPDM. These materials have been commonly used in profile manufacturing for a long time, but they are currently being replaced by more environmentally friendly alternatives.

Note: V.A.V. Group does not produce PVC or EPDM profiles. In most cases, they can be easily replaced by custom-treated TPE, TPV, or silicone materials.

PVC – POLYVINYL CHLORIDE

PVC is a synthetic plastic polymer known for its durability and versatility. It exhibits excellent resistance to chemicals, weathering, and UV radiation. PVC seals and profiles are rigid and provide stability, making them ideal for applications where structural integrity is crucial. Additionally, PVC is cost-effective, making it a popular and affordable choice in the construction industry.

Speaking of construction, PVC is commonly used in applications where structural stability is critical, such as window frames, door frames, and pipe fittings. Its rigid nature ensures long-term durability and resistance to wear and tear. PVC profiles are widely utilized in construction due to their affordability and ability to withstand harsh environmental conditions.

PVC typically has a higher melting point than TPE, making it more suitable for applications where high temperatures may be a concern. Conversely, TPE excels in low-temperature flexibility, ensuring effective sealing even in cold climates. However, TPE can be treated to withstand very high temperatures, up to the point of being fireproof, at which point it can effectively replace PVC.

EPDM

EPDM (Ethylene Propylene Diene Monomer) and TPE (Thermoplastic Elastomer) are both materials commonly used in various industries for their flexibility and durability, but they have distinct differences in terms of composition, properties, and applications.

EPDM is a synthetic rubber made from the polymerization of ethylene, propylene, and a small amount of diene monomers. It has a saturated polymer backbone, which gives it excellent resistance to environmental factors like UV radiation, ozone, and weathering.

The composition itself does not play a significant role in the actual use of the profile, but it does in the manufacturing process. EPDM profiles are a lot harder to join together than TPE or TPV profiles, which means they cannot be “welded” together like our TPE/TPV profiles. To create angles or round shapes from an EPDM profile, the joint requires a joining block or an adhesive, which may become a weak link later on. TPE and TPV profile ends are simply heated, and the two ends are then pushed together to form a very reliable connection that requires no additional adhesives or other materials.

Even though it may lack some of EPDM’s features, TPE is more customizable than EPDM. TPV can be considered a highly functional hybrid between these two materials. In most cases, TPE can replace EPDM, which we have seen in the industry in the past years. One reason for this is that EPDM is typically processed using methods like extrusion, injection molding, and compression molding. It cannot be re-melted and reprocessed after curing. TPEs, however, are thermoplastic, which means they can be melted and reprocessed multiple times. They are well-suited for injection molding, blow molding, and extrusion processes.

This brings us to the biggest difference between EPDM and TPE, the recyclability. EPDM cannot be recycled, so it can only be disposed of as energy waste after its lifecycle has come to an end. It is also the main reason why several companies are looking for more environmentally-friendly alternatives, such as TPE or TPV. EPDM is often cheaper to produce, but because of its disposable nature, the total cost may actually become higher after waste management costs, whereas TPE and TPV can be melted and granulated after use.

ARE YOU LOOKING FOR A PVC OR EPDM REPLACEMENT?

The choice between PVC, EPDM, silicone, and TPE seals and profiles ultimately depends on the application’s specific requirements. Silicone has amazing temperature-resisting properties, PVC offers durability and structural stability, and EPDM offers weather resistance and insulation properties at a lower cost, while TPE provides flexibility, resilience, and environmental benefits. However, our modern solutions for TPE use have increased structural strength to the point where TPE can widely replace PVC and EDPM in most circumstances. 

Understanding the performance characteristics and considering factors such as temperature resistance, environmental impact, and budget constraints will guide the selection process, ensuring the optimal choice for each unique application in the construction and manufacturing industries.

IS TPE BETTER THAN SILICONE?

Between TPE and silicone, there is no clear winner as to which one is “better” since they both excel in their own fields of use. Here is a clear side-by-side comparison of their properties:

As seen in the table, it’s a pretty even match between the two until the optional and special properties, that can be added to silicone profiles in our downstream operations. TPE’s advantage over silicone is that it can be produced in higher hardnesses than silicone and is fully recyclable, whereas silicone has to be disposed of by incineration at the end of its lifecycle*. Silicone easily beats other materials with its wide range of operating temperatures.

* Some recycling centers for silicone exist in Europe. They are few and far between, and the transportation of used silicone profiles from Finland to these centers would ultimately undo any environmental benefits of the recycling itself.

CUSTOM SOLUTIONS BY V.A.V. GROUP

In conclusion, the profile materials we provide all fit the needs and are widely used in construction, heavy industry, and transportation due to their easily customizable properties, high quality, and fast and flexible production times. 

While we might be best known for top-quality seals and profiles for transportation, construction, and heavy industry, and those three categories are indeed the largest sectors we do business with, they are not the only ones. Our ability to create custom extrusion tools lets us produce products for a wide variety of uses, from brewing tanks and composter seals to food-grade feeding tubes for calves.

Combined with flexibility and reliability, we can offer our customers a fast supply of products, with prototypes delivered in two weeks from when we receive the drawings or model of the product. Often, a customer’s R&D process requires several experimental prototypes before the final product design is found, but with our fast prototyping rounds, this part of the process becomes easy and efficient. We design and manufacture products from the start to fit the customer’s specific needs. The goal is to together create a prototype that follows the customer’s plans and that they can approve of without feeling like the resulting prototype is completely unrecognizable from their original idea.

We consider quality an element of reliability and are firmly committed to high-quality production. Our guiding principle is to find the best solution for each customer in order to ensure their success and competitiveness. With our flexible production lines, co-extrusion capabilities, speed in modifying products to customer specifications, and sometimes even co-designing the perfect solution to customers’ problems, we can say that innovativeness is the key driver in our company culture.

READ ABOUT OUR CUSTOMER CASES

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Artikkeli PROFILE & SEAL MATERIAL SELECTION GUIDE julkaistiin ensimmäisen kerran V.A.V. Group.