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. Nowadays TPE (and TPV) are replacing EPDM in many use cases, but why? Let’s dive deeper into their properties to better understand their differences and similarities.
- EPDM: 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.
- 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.
The composition itself does not play a significant role in 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. Now let’s look at the physical properties:
- Physical Properties:
- Excellent weather resistance.
- Good heat resistance, with a temperature range of -50°C to 150°C.
- Excellent electrical insulation properties.
- High resistance to water, steam, and some chemicals.
- Generally rigid in its natural state but can be formulated to be more flexible.
- Maintains its shape even after long periods of compression.
- May become brittle over time.
- Very limited hardness options.
- No colour alternatives, only black available.
- Very robust, thin or small profiles are difficult to produce.
- Excellent flexibility and elasticity.
- Wide range of hardness options, from very soft to quite rigid.
- Wide range of colour options.
- Moderate to excellent resistance to UV radiation and weathering, depending on the specific formulation.
- Good chemical resistance, but it can vary based on the TPE type. TPV, on the other hand, has excellent chemical resistance. In some cases, even greater resistance than EPDM.
- Extremely versatile when it comes to thickness, shape and size.
- Slightly lower heat resistance compared to EPDM, typically up to 90, even 135°C. Lowest temperature is -30°C.
- TPE does not withstand long periods of compression as well as EPDM, but TPV has very similar abilities with EPDM.
We can see that TPE is more customizable than EPDM, even though it may lack some of EPDM’s features, such as withstanding extreme temperatures. 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. To better understand the reason for the change of materials, let’s look at the manufacturing process next:
- EPDM: EPDM is typically processed using methods like extrusion, injection molding, and compression molding. It cannot be re-melted and reprocessed after curing.
- TPE: TPEs are thermoplastic, which means they can be melted and reprocessed multiple times. They are well-suited for injection molding, blow molding, and extrusion processes.
The biggest difference between EPDM and TPE is 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.
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 replace EPDM in most cases.
- Seals and gaskets in automotive, construction, and industrial applications.
- Roofing membranes.
- Electrical insulation.
- Radiator and coolant hoses.
- Construction industry
- Soft-touch grips and handles.
- Overmolded parts and handles on tools and consumer products.
- Automotive interior components, like dashboard trim and cup holders.
- Medical devices and equipment.
- Cable and wire insulation.
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. TPE, on the other hand, is a versatile material with a wide range of hardness options, colours, flexibility, and reprocessability, making it suitable for various consumer and industrial applications where elasticity, wide range of colour options and ease of processing are essential. The choice between EPDM and TPE depends on the specific requirements of the application. 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 surely find the right solution for you!