TPU materials vs. other TPE materials

Before getting into the differences between TPU and TPE, it is important to clarify their relationship. TPE (thermoplastic elastomers) is a term that encompasses different material families, and TPU (thermoplastic polyurethane) is one of them.

Therefore, they are not two equivalent or independent categories. When talking about “TPU vs. TPE”, the comparison should be understood as an analysis between TPU and other thermoplastic elastomer families, whose properties vary depending on their composition, formulation and grade.

Material selection should take into account factors such as abrasion resistance, permanent deformation, operating temperature, exposure to chemicals, UV radiation, feel and manufacturing process.

TPU and TPE: what are the differences?

The main difference to keep in mind is that TPE material is a general term, while TPU material is one of the material families within this group.

TPU typically stands out for combining elasticity, mechanical strength, abrasion resistance and the ability to withstand repeated stresses. Depending on its formulation, it can be adapted to different levels of hardness and application requirements.

TPEs, considered as a whole, cover a much broader range. There are families and grades developed to provide different combinations of elasticity, feel, chemical resistance, service temperature, processability and mechanical performance.

Therefore, the final comparison should always be made between specific families and grades, taking into account the requirements of each application.

Mechanical and performance properties

Mechanical performance is one of the main criteria when selecting a thermoplastic elastomer. In parts subjected to bending, compression, tension, impact or repeated cycles, it is not enough to know the hardness: fatigue, elastic recovery and permanent deformation must also be considered.

Certain TPU grades offer a good combination of tensile strength, elasticity, tear resistance and abrasion resistance. However, the performance of other TPE families can vary considerably depending on their formulation.

The comparison should always be made between specific materials and according to the actual operating conditions.

Hardness, elasticity and feel

Both TPU and other TPE families are available in different hardness levels. Therefore, hardness alone does not determine the flexibility or final behaviour of the part.

Some TPU grades provide a technical and durable feel, while certain formulations from other TPE families are specifically designed for soft, flexible or rubber-like surfaces.

Elastic recovery should also be considered, particularly in parts subjected to repeated compression or bending.

Resistance to wear and deformation

Wear resistance is particularly important in components subjected to friction or continuous contact.

Certain TPU grades offer high abrasion resistance and may be suitable for parts exposed to friction, impact or repeated mechanical cycles.

Permanent compression set, fatigue and recovery after working cycles should also be considered. These properties depend both on the material family and the selected grade, as well as on the application conditions.

Performance under temperature and environmental conditions

Temperature and the chemical environment can significantly affect the behaviour of thermoplastic elastomers.

Both TPU and other TPE families include formulations designed for different service conditions. Therefore, it is not appropriate to assign general thermal or chemical behaviour to all TPEs.

Composition, additives and the selected grade largely determine the material's performance.

Temperature range and dimensional stability

Temperature changes can affect the stiffness, elasticity and dimensions of a part.

Certain TPU grades maintain good mechanical performance within their service ranges, although their properties may change as they approach the recommended temperature limits.

For any TPE family, it is important to analyse not only the maximum and minimum temperatures, but also thermal cycling and the ability to maintain the geometry and functionality of the part.

When dimensional stability is critical, it is advisable to validate the material under conditions similar to those encountered in service.

Resistance to chemicals and weathering

Oils, greases, fuels, cleaning products, moisture and UV radiation can affect each TPE family and grade differently.

Certain TPU grades offer good resistance to specific oils, greases and chemical agents, although there are differences between formulations. Hydrolysis resistance should also be assessed when the material is exposed to moisture or water for prolonged periods.

For outdoor applications, factors such as UV radiation, ozone, moisture and thermal cycling should also be considered. Compatibility should always be evaluated for the specific TPE grade selected.

Processing and manufacturing with TPU and TPE

Different TPE families can be processed using thermoplastic manufacturing processes, although their processing conditions vary depending on their composition and grade.

In processes such as injection moulding, parameters including temperature, pressure, injection speed and when necessary, drying conditions must be carefully controlled.

Proper process definition helps reduce defects, improve dimensional stability and achieve a consistent surface finish.

Moulding, extrusion and ease of processing

TPU and other TPE families can be processed by injection moulding and extrusion to manufacture technical parts, profiles, flexible components or overmoulded elements.

Certain TPU grades require careful moisture control before processing. Other TPE families include formulations specifically designed to facilitate operations such as overmoulding onto rigid substrates.

Flow behaviour, shrinkage, dimensional stability, adhesion and the processing window should be considered from the mould design stage and throughout production setup.

Surface finish and design possibilities

Different TPE families make it possible to achieve different levels of hardness, flexibility and surface finish.

TPU also offers different hardness and finishing options, as well as interesting performance characteristics for parts requiring flexibility and wear resistance.

Mould texture, geometry, injection parameters and the selected grade all influence the final result. In overmoulded parts, compatibility and adhesion between the materials should also be verified.

Common applications of each material

Talking about the applications of “TPU and TPE” requires remembering that TPU is one of the families that make up TPEs.

The selection process consists of determining which family and grade provides the right balance between performance, manufacturing requirements, cost and service life.

When to choose TPU

TPU material may be particularly interesting when a combination of elasticity, mechanical strength and wear resistance is required.

Applications where its use may be considered include:

• Flexible components subjected to wear.
• Protective and impact-absorbing elements.
• Technical parts exposed to repeated bending.
• Components subjected to friction.
• Wheels, rollers and contact elements.
• Overmoulded parts combining rigidity and flexibility.
• Industrial components with demanding mechanical requirements.

These applications are not exclusive to TPU. Other TPE families may provide suitable solutions depending on the project requirements.

When to choose TPE

Talking about “choosing TPE” does not mean choosing it over TPU, since TPU is already a TPE.

The actual question is when another TPE family may be more suitable. Some families may be particularly interested when flexibility, feel, ergonomics, environmental resistance, overmoulding or ease of processing are prioritised.

Possible applications include:

• Handles and grip surfaces.
• Buttons and interface elements.
• Flexible components for consumer products.
• Overmoulded parts on rigid substrates.
• Sealing and protective elements.
• Components where feel and ergonomics are relevant.
• Parts with different hardness and flexibility requirements.

How to choose between TPU and TPE based on the application

The expression “choosing between TPU and TPE” should be interpreted correctly: TPU belongs to the TPE family.

The actual decision is to determine whether TPU is suitable for the application or whether another thermoplastic elastomers family should be selected.

Selection should begin with the actual service conditions. If abrasion resistance, mechanical strength and performance under repeated loads are priorities, certain TPU grades may be a suitable option.

If the project requires other combinations of feel, ergonomics, flexibility, environmental performance or overmoulding, other TPE families and grades should be evaluated.

The manufacturing process, production volume, part geometry and tolerances should also be considered.

The technical criteria that matter most when selecting a material

The main factors that should be analysed are:

1. Mechanical loads.
    Tension, compression, bending, impact, abrasion and repeated cycles.

2. Hardness and elasticity.
    In addition to hardness, elastic recovery and permanent deformation should be assessed.

3. Temperature.
    Maximum and minimum temperatures, as well as thermal cycling.

4. Chemical exposure.
    Oils, greases, fuels, detergents, water and other substances.

5. Environmental conditions.
    Especially UV radiation, moisture, ozone and temperature changes in outdoor applications.

6. Manufacturing process.
    Process compatibility, mould design and production requirements.

7. Finishes.
   Texture, feel and perceived quality when the part is visible or handled.

8. Service life.
    The ability to maintain performance throughout the intended period of use.

Selection should be made between specific TPE families and grades, seeking the right balance for the actual application conditions.

Common mistakes when comparing TPU and TPE

The main mistake is to consider TPU and TPE as two equivalent or independent materials. TPE encompasses different thermoplastic elastomer families, and TPU is one of them.

Therefore, statements such as “TPU is more resistant than TPE” or “TPE is more flexible than TPU” are too general unless the specific family and grade being compared are clearly identified.

Another common mistake is selecting a material based solely on hardness or price. Two materials with the same hardness can behave differently when exposed to abrasion, temperature or chemicals, while the actual cost also depends on the manufacturing process, performance, service life and maintenance requirements.

It is also not enough to analyse a single catalogue property. For example, abrasion resistance alone does not guarantee that a material is suitable if the part will be exposed to high temperatures or incompatible chemicals.

Therefore, material selection should be approached as a comparison between specific TPE families and grades, including TPU, based on the complete set of part requirements.

When requirements are demanding, material characterisation and validation through testing can be decisive in ensuring performance throughout the component's service life.

Do you need to choose between TPU and TPE for a specific part? At OSF, we can help you select the most suitable material and manufacturing process based on the requirements of your application. Contact our technical team and we will assess your project.