Tetron B: Bronze-Filled PTFE for Hydraulic Seals and Wear Bands

Improving Wear Resistance and Dimensional Stability in Hydraulic Applications

Hydraulic cylinders operate under demanding conditions. Repeated sliding movement, high contact pressures, friction and side loading can contribute to seal wear, material deformation and premature component failure.

Selecting the right material for hydraulic seals and wear bands is critical to equipment reliability, service life and maintenance costs.

Tetron B, Dotmar's bronze-filled PTFE, combines the low-friction properties of polytetrafluoroethylene (PTFE) with improved wear resistance, mechanical stability and thermal conductivity. It is an excellent material to consider for demanding hydraulic sealing and guiding applications where virgin PTFE may not provide sufficient mechanical performance.

Why Choose Bronze-Filled PTFE?

Virgin PTFE offers excellent chemical resistance, very low friction and a wide operating temperature range. However, under sustained loads, it can deform over time through creep or cold flow, while repeated sliding contact can contribute to wear.

Bronze reinforcement helps address these limitations, offering several advantages for hydraulic applications:

• Improved wear resistance: Helps withstand repeated sliding contact, potentially extending component service life and reducing maintenance requirements.
• Reduced creep and deformation: Improves dimensional stability under load and helps maintain component geometry. Its improved mechanical properties can also help resist seal extrusion.
• Improved heat dissipation: Bronze increases thermal conductivity, helping transfer frictional heat away from the sliding interface, and therefore extending wear service life.
• Low-friction performance: Retains the characteristic sliding properties of PTFE, supporting smooth movement in dynamic applications.

Applications in Hydraulic Systems

Tetron B is suitable for consideration in a range of hydraulic components, including:

• Piston and rod seals: For dynamic sealing applications requiring low friction and wear resistance.
• Wear bands and guide rings: To guide moving assemblies, manage lateral loads and help prevent metal-to-metal contact.
• Piston rings: Where wear resistance and dimensional stability are important.
• Backup and supporting rings: Where the material's properties suit the seal design and operating conditions.

The correct material selection depends on operating pressure, temperature, sliding speed, hydraulic fluid compatibility, mating surface finish and component design.

How Does Tetron B Compare with Other Materials?

Choosing the right material requires balancing friction, wear resistance, mechanical strength and chemical compatibility.

Virgin PTFE: Offers excellent chemical resistance and very low friction, but has lower resistance to wear and creep under demanding mechanical loads.

Glass-filled PTFE: Provides improved stiffness and wear resistance. Bronze-filled PTFE may be preferable where reduced abrasion against the mating surface and improved thermal conductivity are priorities.

Carbon-filled PTFE: Offers good wear resistance and reduced creep. The choice between carbon and bronze formulations depends on the application, lubrication conditions, mating surfaces and chemical compatibility.

Acetal and nylon: These engineering thermoplastics offer good mechanical strength and are used in guide rings and wear components. However, they have different frictional, temperature and chemical resistance characteristics. Nylon also absorbs moisture, which can affect dimensional stability. PTFE compounds can offer advantages in applications where low friction and dynamic sealing performance are critical.

No single material is best for every application. Bronze-filled PTFE should be assessed against the actual operating conditions and performance requirements.

Dotmar: In-House Compounding and Stock-Shape Manufacturing

Dotmar compounds PTFE grades and manufactures PTFE stock shapes in-house, including billets, cylinders and plate/sheet. This provides customers with practical advantages beyond material performance.

• Reduced lead times: In-house manufacturing reduces reliance on specially imported material, helping improve material availability and responsiveness.
• Optimised stock shapes: Stock dimensions can be selected to suit the component and machining requirements, helping minimise material waste.
• More efficient machining: Selecting an appropriate starting shape and size can reduce machining time, material consumption and overall manufacturing costs.

This combination of material expertise and local manufacturing capability helps Dotmar support customers with hydraulic sealing and wear-component requirements, from material selection through to the supply of suitable stock shapes for machining.

Talk to Dotmar About Your Application

Whether you are developing a new hydraulic component or looking to improve the performance of an existing seal or wear band, Dotmar can help assess whether Tetron B bronze-filled PTFE is the right choice.

Contact Dotmar to discuss your application and discover how the right material and stock-shape selection can improve performance, lead times and manufacturing efficiency.