High-performance Hydraulic Seal for Extreme Conditions

            High-performance Hydraulic Seal for Extreme Conditions

PR Newswire

PLYMOUTH, Mich., July 23, 2014

PLYMOUTH, Mich., July 23, 2014 /PRNewswire/ --An innovative materials
combination consisting of two distinct polyurethanes provides Freudenberg-NOK
Sealing Technologies (Freudenberg-NOK) new HDR-2C rod seal with special
extrusion stability at high pressures and great flexibility at temperatures
down to -50 degrees C. This innovative materials combination is particularly
well suited to address environmental challenges encountered in the fluid power

Seals in hydraulic cylinders must withstand major stresses. They are exposed
to severe pressure and temperature fluctuations as well as the hydraulic fluid
in use. But they still must ensure reliable leak tightness across a wide
performance spectrum over the entire period of use. The two-component
technology of the HDR-2C handles the stresses on the different functional
areas of a rod seal.

The individual sections of rod seals are exposed to very different stresses
and must meet requirements that in part demand conflicting material
characteristics. For this reason, standard seals are frequently manufactured
with a medium-hard material – a compromise that decreases the seals'
reliability and service life. The reason: On one hand, with the help of an
excellent press fit, the seal back must prevent a seal's axial shift due to
pressure and frictional forces. And it must be as extrusion-resistant as
possible on the gap side. On the other hand, the seal lips require a softer,
more flexible material. This is the only way a static lip can reliably seal
the ground of the groove and that a dynamic seal can ensure high leak
tightness and resistance to wear even at low temperatures despite significant
axial and radial stresses. The conflicting requirements of the different
functional areas thus range from high rigidity and higher extrusion resistance
(hard material) to less permanent deformation and greater elasticity (soft

The company's groove ring combines the advantages of two high-performance
materials with different physical characteristics in just one element. The
seal back is made from polyurethane 98 AU 928, a material with a hardness
grade of 98 Shore A, which stands out for great stability under high operation
pressures. The seal lips made of polyurethane 92 AU 21100 have very good
dynamic sealing properties due to the material's high elasticity and low
compression set. Compared to a standard seal, the HDR-2C's two-component
technology offers a significantly improved performance range as well as much
easier installation. Greater gap dimension tolerances, reliable use at
operating pressures up to 500 bar and the high leak tightness in the
temperature range from -50 °C to 110 °C make the new rod seal from
Freudenberg-NOK an extremely high-performance sealing solution offering
outstanding value for the money.

About Freudenberg-NOK Sealing Technologies

Freudenberg-NOK Sealing Technologies is the Americas joint venture between
Freudenberg and Co. in Germany and NOK Corp. in Japan. Freudenberg-NOK is a
leading producer of advanced sealing technologies for a variety of markets
including: aerospace; agriculture; appliance; automotive; construction;
diesel engine; energy; food and beverage; heavy industry; and pharmaceutical.
Founded in 1989 under the legal name Freudenberg-NOK General Partnership,
Freudenberg-NOK is headquartered in Plymouth, Mich. and operates more than 20
facilities across the Americas. For additional information, please visit

SOURCE Freudenberg-NOK Sealing Technologies

Website: http://www.fnst.com
Contact: Cheryl Eberwein, Director, Media Relations, Office: +1 734 354 7373,
E-Mail: cheryl.eberwein@fnst.com; or Leslie Dagg / Adriana Van Duyn, Bianchi
PR, Office: +1 248 269 1122, E-Mail: ldagg@bianchipr.com /
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