EPDM (Ethylene Propylene Diene Monomer) and TPE (Thermoplastic Elastomer) are both materials commonly used in various industries for their flexibility and durability, but they differ in composition, properties, and applications. Nowadays, TPE (and TPV) are replacing EPDM in many cases, but why? Let’s dive deeper into their properties to better understand their differences and similarities.
Composition
EPDM
EPDM is a synthetic rubber made from the polymerization of ethylene, propylene, and a small amount of diene monomers. Its saturated polymer backbone gives it excellent resistance to environmental factors like UV radiation, ozone, and weathering.
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.
Differences
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 much harder to join 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. Now let’s look at the physical properties:
Physical Properties:
EPDM
EPDM is a highly versatile material known for its excellent weather resistance, making it ideal for applications exposed to harsh environmental conditions. It performs well in extreme temperatures, with a range of -50°C to 150°C, ensuring durability in both cold and hot environments. Additionally, EPDM boasts excellent electrical insulation properties, making it suitable for various electrical applications.
This material is also highly resistant to water, steam, and certain chemicals, enhancing its suitability for a wide range of industrial uses. While EPDM is generally rigid in its natural state, it can be formulated to offer greater flexibility, catering to specific requirements. One of its key advantages is its ability to maintain shape and integrity even after prolonged compression, ensuring long-term reliability in demanding conditions.
However, EPDM has some limitations. Over time, it may become brittle, which can affect its performance in certain applications. The material also has very limited hardness options and is available only in black, with no color alternatives. Additionally, producing very robust, thin, or small profiles from EPDM can be challenging due to its inherent properties. Despite these drawbacks, EPDM remains a popular choice in industries requiring durable, weather-resistant materials.
TPE
Thermoplastic elastomers (TPE) are known for their excellent flexibility and elasticity, making them highly adaptable for a variety of applications. One of the key advantages of TPE is its wide range of hardness options, which allows for customization from very soft to quite rigid materials. This versatility is further enhanced by the availability of a broad spectrum of color options, making TPE a popular choice in industries where aesthetics are important alongside functionality.
TPE offers moderate to excellent resistance to UV radiation and weathering, depending on the specific formulation, which makes it suitable for outdoor use. It also has good chemical resistance, though this can vary depending on the type of TPE. For example, TPV (Thermoplastic Vulcanizates), a type of TPE, boasts excellent chemical resistance, often surpassing that of EPDM. This makes TPV particularly useful in environments where exposure to harsh chemicals is a concern.
When it comes to manufacturing, TPE is extremely versatile, allowing for a wide range of thicknesses, shapes, and sizes to be produced with ease. However, TPE has slightly lower heat resistance compared to EPDM, typically withstanding temperatures up to 90°C, and in some formulations, up to 135°C. Its performance at lower temperatures is also robust, functioning effectively down to -30°C.
One limitation of TPE is that it does not withstand long periods of compression as well as EPDM. However, TPV, a subtype of TPE, offers compression resistance that is very similar to that of EPDM, making it a suitable alternative in applications where long-term durability is crucial. Overall, TPE’s flexibility, color options, and adaptability make it a versatile material choice for a wide range of industrial and consumer applications.
TPE is more customizable than EPDM, even though it may lack some of EPDM’s features, such as withstanding extreme temperatures. TPV (thermoplastic vulcanizates) can be considered a highly functional hybrid between these two materials. In most cases, TPE can replace EPDM, which has been a growing trend in the industry in recent years. To better understand the reason for the change of materials, let’s look at the manufacturing process next.
Processing
EPDM is a thermoset material, meaning that once it undergoes the curing process, it cannot be melted or reprocessed. This irreversible process is key to its durability and stability, as the material’s chemical structure becomes permanently cross-linked during curing. EPDM is typically processed using methods such as extrusion, injection molding, and compression molding. Extrusion is commonly used to produce continuous profiles, such as seals and gaskets, where the material is forced through a die to create long, consistent shapes. Injection molding allows for more complex shapes by injecting the EPDM material into a mold under high pressure. Compression molding, on the other hand, is used to form larger, simpler parts by compressing the material in a heated mold. Despite its versatility in processing methods, the fact that EPDM cannot be re-melted and reprocessed after curing means that any waste or excess material generated during production cannot be reused, which can impact the overall material efficiency.
In contrast, thermoplastic elastomers (TPEs) offer a significant advantage in terms of reprocessability. Unlike EPDM, TPEs are thermoplastic, which means they can be melted and reprocessed multiple times without significantly degrading their properties. This characteristic makes TPEs highly versatile and more sustainable, as waste material from the manufacturing process can often be recycled and reused. TPEs are well-suited for a variety of processing methods, including injection molding, blow molding, and extrusion. Injection molding is particularly efficient for producing complex, detailed parts with high precision, making TPEs ideal for a wide range of applications in industries like automotive, consumer goods, and medical devices. Blow molding is used to create hollow parts, such as bottles or flexible hoses, while extrusion is similar to EPDM processing and is used for continuous profiles like tubing or weather seals. The ability to re-melt and reprocess TPEs not only reduces material waste but also allows for greater flexibility in manufacturing, making them a preferred choice for many industrial applications where efficiency and sustainability are important considerations.
The most significant difference between EPDM and TPE is their recyclability. EPDM cannot be recycled, so it can only be disposed of as energy waste after its lifecycle has ended. This 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 increase after waste management costs. In contrast, TPE and TPV can be melted and granulated after use.
But what are the main applications of EPDM and TPE/TPV profiles? We have listed the most common ones below, but with certain additions or alterations, TPE/TPV can usually replace EPDM.
Applications
EPDM
EPDM is a highly versatile material used across various industries due to its exceptional durability and resistance to environmental factors. In the automotive sector, EPDM is widely employed in seals and gaskets, which are crucial for maintaining the integrity of vehicle components. Its ability to withstand extreme temperatures and harsh conditions makes it ideal for use in engines, transmissions, and other critical systems. Additionally, EPDM is the material of choice for radiator and coolant hoses, where its heat resistance and flexibility ensure reliable performance in high-temperature environments.
In the construction industry, EPDM is valued for its weather resistance and long-lasting durability. It is commonly used in roofing membranes, providing a watertight and UV-resistant solution that can last for decades with minimal maintenance. EPDM is also essential for weatherstripping in buildings, creating tight seals around windows and doors to prevent water, dust, and air from entering, thereby enhancing energy efficiency and protecting interior environments.
Beyond construction and automotive uses, EPDM’s excellent electrical insulation properties make it ideal for insulating cables and wires in various industrial and consumer electronics. Its resistance to water and weathering ensures reliable performance even in harsh conditions, making it a preferred material for maintaining the safety and functionality of electrical systems.
Overall, EPDM’s unique combination of flexibility, durability, and resistance to environmental factors makes it indispensable in a wide range of applications, from automotive seals to roofing membranes and electrical insulation. Its ability to perform reliably in demanding conditions ensures its continued use across multiple industries.
TPE
Thermoplastic elastomers are prized for their flexibility, versatility, and wide range of applications across various industries. In the construction industry, TPE is commonly used for soft-touch grips and handles, offering both comfort and durability in tools and equipment. Its ability to be over-molded onto other materials makes it ideal for creating ergonomic, slip-resistant surfaces, enhancing the usability of hand tools and other products frequently handled by workers.
In the automotive industry, TPE is extensively used in interior components, such as dashboard trim, cup holders, and other soft-touch elements. The material’s ability to combine flexibility with a durable, aesthetically pleasing finish makes it perfect for enhancing the look and feel of vehicle interiors. TPE’s versatility also allows it to be used in over-molded parts, providing seamless integration of different materials in automotive applications.
TPE’s properties make it well-suited for medical devices and equipment. Its flexibility, along with its ability to be sterilized, makes TPE an excellent choice for various medical applications, from tubing and seals to soft-touch surfaces on medical instruments. TPE’s biocompatibility ensures that it can be safely used in direct contact with the human body, which is crucial for many medical devices.
Additionally, TPE is widely used for cable and wire insulation due to its good electrical insulation properties and resistance to environmental factors. Its ability to be re-melted and reprocessed without losing its properties also makes TPE a more sustainable choice, particularly in applications where cables and wires need to maintain flexibility and durability over time. The combination of these features makes TPE a highly adaptable material across multiple sectors, from construction to automotive and medical applications.
Why you should consider replacing EPDM with TPE
In summary, EPDM is a specialized synthetic rubber known for its excellent weather and environmental resistance, making it a good solution for outdoor applications and sealing purposes. On the other hand, TPE is a versatile material with a wide range of hardness options, colors, flexibility, and re-processability. It is suitable for various consumer and industrial applications where elasticity, a wide range of color options, and ease of processing are essential. The choice between EPDM and TPE depends on the application’s specific requirements. If TPE can directly replace EPDM, our clients usually select TPE profiles for their reusability and other advantages. TPV is not as widely used as TPE, but it offers a solution in cases where TPE reaches its limits in replacing EPDM.
Do you want to hear more about replacing EPDM profiles with more environmentally friendly alternatives? Contact our sales to map out your needs, and we will find the right solution for you!
How to get your TPE and Silicone profiles from V.A.V. Group
How does the process of ordering, designing, and producing your custom-made seals and profiles work? Here’s our quick guide that maps out the entire journey from beginning to end!
