Hydraulic systems often operate under severe and even extreme conditions. The materials of the sealing gaskets must ensure reliable operation, regardless of the conditions under which they operate, including aspects of climate such as relative humidity in a tropical environment with regard to hydrolysis of the seals and polyurethane gaskets.
Even the seals that meet these requirements, it is common for them to wear out due to sudden changes in temperature or inadequate maintenance. One particular case is the rental of heavy machinery, where collars, scrapers, guides and other parts of the hydraulic circuits are subjected to extreme use, often exceeding the working capacity of the equipment. Consequently, due to a higher number of breakdowns, maintenance must be much more intense, being basically corrective (instead of predictive) and with an associated increase in operating costs.
In this scenario, the development of new materials always generates expectations in terms of increasing the service life of collars, O-rings, scrapers y guides. We pursue a significant improvement in equipment performance.
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The solution of our partner Freudenberg
More than 40 years ago, Freudenberg introduced the polyurethane as a high-performance gasketing material, setting new process standards. The experience in polyurethane gaskets accumulated over the years and the know-how from Freudenberg, converge in the new generation of polyurethane, the 94 AU 30000, an excellent material for high performance gaskets.
The polyurethane 94 AU 30000 has been designed to provide a wide variety of applications, with longer service life and water resistance compared to a conventional polyurethane. Starting from the formulation of a polyurethane conventional, we get improve thermal resistance, without prejudice to the other properties. Even at +120 °C, the material is reliable. The key parameters of hardness and tensile strength are comparable to those already known from other polyurethanes from Freudenberg.
The viscoelastic behavior of the new material has been adjusted so that flexibility is retained over a wide temperature range. In this way, we ensure that the sealing gaskets on the basis of polyurethane 94 AU 30000 have sufficient flexibility at low temperatures and remain stable at high temperatures. Thus, with this material, we increase the options for use in severe conditions, hitherto reserved for special materials.
The polyurethane 94 AU 30000 proves to be far superior to conventional polyurethanes, The results we have obtained on the test bench demonstrate this. For example, for the same time base, the material 94 AU 30000 shows no signs of wear unlike other materials, and its wear resistance is almost 30 times higher than that of %. In addition, we have tested it in mineral hydraulic fluids up to +120 °C and found it to be resistant to hydrolysis at +80 °C.
We have also increased its extrusion stability (damage at high pressures), greatly reducing deterioration due to pressure peaks. The following graphs compare the polyurethane 94 AU 30000 with other conventional polyurethanes.
Advantages and benefits of 94 AU 30000
- High extrusion stability allowing it to work up to 50 MPa.
- Long service life due to high tear and wear resistance.
- Thermal stability in the range of -35 ºC to +120 °C.
- Especially recommended for mineral and biodegradable hydraulic fluids.
- Excellent ozone resistance.
If you have to carry out maintenance work, keep in mind the new polyurethane 94 AU 30000. If you want more information about our polyurethane gaskets, please contact us here.