Polyurethane (PU) materials offer outstanding wear, extrusion and abrasion resistance with good elasticity and low compression set.

Zurcon® Z25 is an advanced high temperature proprietary polyurethane (PU) from Trelleborg Sealing Solutions. It combines excellent viscoelastic properties and high tensile strength at extreme operating temperatures from -35°C up to +130°C/-31°F to +270°F, and can operate in pressures up to 40 Mpa/5,800 psi without a Back-up Ring.

Selection of PU Rod Seals in Zurcon Z25

Selection of PU Rod Seals in Zurcon Z25

Recommended for Challenging Environments

The premium polyurethane material is recommended for hydraulic applications in challenging environments where high temperature performance is required, due to its improved extrusion resistance and compression set. Zurcon® Z25 is ideal for use in heavy duty cylinder sealing applications including industrial and mobile applications with limited cooling systems or cylinders exposed to high-temperature painting processes, extending sealing life and prolonging service life.

With excellent low friction characteristics and superior dynamic performance, Zurcon® Z25 is also suitable for rotary applications such as swivel joints, where heat is generated by high pressures and low speeds.

Zurcon® Z25 – Physical Properties
Hardness DIN 53 505 Shore A 95 +/- 2
Density DIN EN ISO 1183-1



1.20 +/- 0.020

0.043 +/- 0.0007

Modulus 100 % DIN 53 504





Tensile Strength DIN 53 504





Elongation at Break DIN 53 504 % 520
Rebound Resilience DIN 53 512 (6mm) % 47
Tear Strength DIN ISO 34-1





DIN ISO 815 (B) % 22
C.S.70h/+100°C70h/+212°F DIN ISO 815 (B) % 36
Temperature Range  



-35°C to +130°C

31 °F to +270 °F

By combining the optimum products and materials, original equipment manufacturers can meet the increasing demands of hydraulic applications. For a recommendation on the best product and material for your application contact your local Trelleborg Sealing Solutions marketing company.

What's your view?

Stephen Cheng
Dear Sir/Madam, We are a leading global switch manufacturer. Currently, we are developing a new switch series that it has to be operational under water. Hence, sealing is one of the critical area that we have to take care. We need a sealing component like a bellow installed between the plunger(axial movable part) and switch body (stationary sub-assembly) to prevent the water from entering the internal structure of switch body. We tried a material called solid silicone rubber with failure of actuating cycle of 400k. Our target actuating cycle is 1000K. So the current design is far below the target. May I know if you have any recommendation for us ? Our bellow design is quite small one that the outer diameter is just talking about 9.8mm with inner diameter of about 5.16mm. The plunger O.D. is 5.9mm so the interference fitting is about 0.74mm. The possible compression for bellow is about 0.7mm.
11 August, 2016

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