94 au 30000

Article first appeared in Power Transmission Engineering blog on November 14, 2017.

Freudenberg Examines Sealing Requirements for Heavy-Duty Equipment

The seals and the hydraulic systems of any piece of mining, construction, agricultural or other heavy industry equipment operate under extreme conditions. Variable temperatures, aggressive hydraulic oils, dust and extended periods of operation place seals and their tribological systems under continuous duress. A new generation of material, 94 AU 30000, expands the boundaries for polyurethane use. This innovative compound can be used in standard cylinder applications where higher pressures, larger extrusion gaps, reduced internal friction, improved hydrolysis resistance and compatibility with bio fluids, among other factors, are important. DMRW2 hydraulic wipers made from 94 AU 30000 and sheet metal and the availability of this polyurethane as part of Freudenberg Sealing Technologies’ Xpress rapid replacement part service are applications discussed in the following article.

Today’s extreme environmental climates place extreme demands on the material and structure of the hydraulic seals used to maintain the performance and operation of heavy-duty equipment.  The excavators, tractors, backhoes and tunnel boring machines that grind through the earth every day must work harder, longer, cleaner and more cost efficiently than ever to feed the plant, build its infrastructure and harvest its natural resources.

Sealing requirements for these machines must now include high values for tensile strength and elongation at break, resistance to oils and ozone, high elasticity and abrasion resistance. Polyurethane materials (PU) have traditionally met these industrial requirements. In comparison with elastomers, PU has a four times greater capacity for mechanical resistance, as well as outstanding resistance to ozone. At the same time, it stands up well to the stresses of mineral-based fluids.