Home News Resilon® Polyurethane - Parker Hannifin 4300

Resilon® Polyurethane - Parker Hannifin 4300

Uniquely formulated polyurethane for high-performance hydraulic sealing with maximum durability.

Industrial seals are often used when other sealing materials can’t meet performance standards under harsh conditions such as very high temperatures, high vibration, or exposure to solvents or other chemicals. 

The innovative Parker Hannifin 4300 Resilon® Polyurethane hydraulic seals offer unparalleled strength, stability at high temperatures, and resilience under variable conditions. Overall, Parker Resilon Polyurethane seals deliver superior performance and long-term durability in the most critical hydraulic applications.

Contact Wyatt Seal to speak to an expert about Parker 4300 Resilon Polyurethane hydraulic applications, capabilities and options to maximize seal life expectancy.


Resilon® Polyurethane Product Features

(Parker 4300, Parker 4301, Parker 4304) 

The chemical structure of Parker’s PPDI-based Resilon® polyurethane formulation yields superior dynamic properties in seals. Altogether, the unique compound outperforms traditional thermoplastic polyurethanes (TPUs), offering greater strength and durability in hydraulic operations with routinely rapid cyclic loading. 

The Resilon® polyurethane seal:

  1. Withstands conditions that other polyurethanes cannot

  2. Performs over a broader range of temperatures

  3. Creates a stronger seal and retention of seal counter-force

  4. Delivers superior resistance to wear for extended seal life

  5. Allows zero extrusion under the highest pressure within specifications range

  6. Provides superior compression set resistance under fluctuating pressures

Available Parker 4300 special formulations:

  1. Extrusion resistant (4304) formulation

  2. Water-resistant (4301) formulation


Resilon® Polyurethane

Parker’s unique PPDI-based Resilon® polyurethane seals deliver the most effective general sealing performance of any TPU formulation available on the commercial market today. Resilon® provides exceptional heat resistance. Tensile testing measures of TODI, MDI, and PPDI (4300) indicate higher resilience in Resilon® PPDI. Furthermore, at increased temperatures, Resilon® demonstrates a higher softening temperature for more sustainable abrasion resistance, better compression set resistance, increased rebound (resilience), and longer overall resistance to wear.

Those are the core concerns in hydraulic applications that require sealing that is highly effective and provides long-term sealing endurance. Overall, the Parker Resilon® polyurethane seal provides better sealing for heavy-duty hydraulics applications than any comparable hydraulic seal on the market.


What to Consider When Selecting Resilon® Polyurethane Seals

Naturally, seals must be manufactured with the right material and in the right size to function as designed and last over time when used routinely under extreme conditions. 

There are some obvious things to consider when selecting seals, such as size and cost, but here are some additional factors that should be considered as well:

  1. Shore Hardness: The hardness of the seal material is measured with a durometer scale to help ensure that gas or liquid under high pressure remains well sealed.

  2. Tensile Strength: The level of pressure a seal can withstand without breaking or warping is critical to a successful seal design for high-pressure applications.

  3. Temperatures: Seals must be designed to function well through rapid temperature changes and inconsistent fluctuation between very high and very low temperatures.

  4. Stretch Capacity: Seals are pliable equipment components that must be installed to fit ideally in the groove between parts and then stretched by some amount to seal thoroughly. (More than 1 - 5% requires a custom seal.)


Resilon® Polyurethane Materials

Physical Properties




Hardness, Shore A, pts




Tensile Strength at Break, ps




Ultimate Elongation, %




100% Modulus, psi




Compression set at 158°F, %




Rebound, %

not applicable

-35 to +225

not applicable

Temperature Range, °F

in oil

in hot water


-65 to +275



-35 to +275

-35 to +225


-65 to +275



Sealing Material Grade Options

Bases used for thermoplastic polyurethane (TPU) seal material compounds are:

  1. P-phenylene diisocyanate (PPDI)

  2. Diphenyl diisocyanate (TODI)

  3. Diphenylmethane diisocyanate (MDI)

Foundationally, these materials provide resistance to abrasion and durability, as can be expected from quality polyurethane seals. However, additional performance features are needed for some applications. 

For example, high heat resistance, rebound (resilience), compression set resistance, and other key characteristics of more advanced polyurethane seals are called for in hydraulic applications that must have reliable seals that last over time. These are the conditions under which PPDI, MDI, or TODI formulae demonstrate their levels of efficacy.

The ground-breaking Parker 4300 PPDI-based Resilon polyurethane seals deliver superior sealing performance and durability over all other commercial-grade TPU seal formulations. Resilon’s top-quality performance features include, for example:

Wide Ranging
Seal Applications

Engine rod seals, piston seals, shock absorbers, hydraulic cylinders, industrial machinery, construction equipment, and other light to heavy-duty applications.

Exceptional Heat Resistance

In rebound testing, the Resilon PPDI formulation indicated a lower ratio of heat/energy absorption across the range of applications as well as a higher softening temperature.

Exceptional Rebound

Resilon 4300 polyurethane demonstrated higher resilience in contrast to other TPU materials tested. A faster rebound is important under extreme pressure shock and in maintaining seal integrity of piston or rod lip contact.


Why Choose Wyatt Seal

Wyatt Seal has built our brand on creating reliable and innovative custom seals for a wide range of industries and applications. Our state-of-the-art seal design process helps ensure that every custom seal you need is precision made and ideally engineered for the specific conditions of your project. You provide your specifications, and we provide a guaranteed solution.

Collaborating with our industry’s best seal experts at Wyatt Seal helps you avoid common mistakes and obtain a highly effective and durable sealing solution. 

Top-quality Parker 4300 Resilon Polyurethane hydraulic seals offer long-term durability and ideal performance under extreme pressure without warping or breaking. 


If you need help navigating this process to find the right seal for your project, talk to a seal expert at Wyatt Seal. We’ve spent 50 years building relationships with seal manufacturers worldwide to offer you access to thousands of seals, gaskets, O-rings, and other specialty items for any application.



Most Recent Posts

Sealing Made Simple with Simriz® 485

When you’re working with sealing solutions, the material is the bedrock of the entire technology. Freudenberg FFKM Simriz® 485 provides an exceptional foundation as our general-purpose solution within the FFKM Simriz® portfolio.

An Exploration of Seal Defects and Failures

Seals serve as essential components across various industries, ensuring containment, preventing leaks, and maintaining operational efficiency. However, their effectiveness can be compromised by a range of defects, each with its own set of consequences.


In response to the imperative to reduce greenhouse gas emissions, Carbon Capture Utilization and Storage (CCUS) has emerged as a vital solution. CCUS technologies offer the potential to capture and store carbon dioxide (CO2) emissions from industrial sources, preventing their release into the atmosphere.