Polyurethanes are thermoplastic elastomers which demonstrate the characteristics of elastomers over a wide temperature range and in addition have the processing behaviour of thermoplastics. They can be melted at high temperature and can be processed with traditional thermoplastic processing techniques. Polyurethanes offer outstanding mechanical properties like wear restistance.
U-1003 is a thermoplastic polyurethane elastomer (TPU) which is a standard grade for sealing applications. It offers good mechanical properties and is mostly used for energized rod seals, energized piston seals and wipers.
ECOPUR, U-1023, U-1029
ECOPUR, U-1023 and U-1029 are premium sealing grade thermoplastic polyurethane elastomers (TPU), offering low compression set, excellent pressure and abrasion resistance as well as high tensile properties and tear strength. In sealing applications, these grades are mostly used for U-cups, lip seals, wipers and packings, but may also be used for dampers and other customized parts. Products of these materials can be used in mineral oil, in water up to 40°C and in bio-degradable hydraulic oils like vegetable oils and synthetic esters up to 60°C. Depending on the seal design and the housing conditions, seals made of ECOPUR, U-1023 or U-1029 can be used up to 400 bar (for high pressure demands, experts from SKF recommend to use anti-extrusion-rings).
H-ECOPUR is a hydrolysis-resistant thermoplastic polyurethane elastomer (TPU). It combines the engineering properties of ECOPUR with a high resistance to hydrolysis which is otherwise rarely found in polyurethanes. It is stable in water up to +90°C and has an outstanding stability in mineral oil. Because of its resistance to hydrolysis, H-ECOPUR can be used for water hydraulic and for applications in mining, tunneling and presses. H-ECOPUR is particularly recommended for the use in pure and seawater, for HFA and HFB fluids and biologically degradable hydraulic fluids (vegetable oils and synthetic esters) and food articles. H-ECOPUR meets food contact regulations according EC1935/2004 and FDA.
T-ECOPUR (TPU) is modified for low temperature applications. The properties of T-ECOPUR are similar to those of ECOPUR, but the minimum service temperature is extended to -50°C. For that reason, T-ECOPUR is most suitable for applications in severe climate conditions and processes for frozen goods.
G-ECOPUR is a casted hydrolysis-resistant polyurethane-elastomer (CPU) with similar properties to H-ECOPUR, especially regarding its chemical stability. G-ECOPUR can be used in the same hydraulic fluids as H-ECOPUR. Generally, G-ECOPUR is used for seals with a diameter from 540 mm up to 4000 mm, where seals can be made in one piece. Larger diameters are feasible using our special welding technique.
G-ECOPUR 54D is a casted hard grade hydrolysis resistant polyurethane (CPU) most suitable for heavy duty large diameter applications. It has comparable chemical and mechanical properties to G-ECOPUR but with higher shore hardness and improved friction and wear characteristics.
S-ECOPUR (TPU) has been optimized with regard to the tribological characteristics of wear resistance. This was achieved by the addition of a synergetic combination of solid lubricants. This special material is therefore best suitable for most applications with starved lubrication such as water hydraulics and oil-free pneumatics.
The X-ECOPUR polyurethanes are harder grades of ECOPUR.
Compared to standard materials, harder grades show nearly the same tensile strength and elongation at break at a considerably higher stiffness, as well as higher tear strength. X-ECOPUR versions have higher extrusion resistance than standard polyurethanes and therefore allow higher pressure at same geometries. The X-ECOPUR grades have increased wear resistance, extended lifetime and a strongly reduced tendency to stick-slip compared to standard polyurethanes.
The composition of X-ECOPUR (TPU) provides outstanding friction and wear properties as well as high pressure resistance. Therefore, the material is well suited for the use as a composite seal, for wipers working in heavy-duty applications as well as for engineered plastic parts that require high elasticity and superior resilience. Due to the exceptional extrusion resistance, seals made of this material work at higher pressure level and larger clearance, than those made of standard polyurethanes and PTFE compounds.
Compared to the standard grade H-ECOPUR, X-ECOPUR H (TPU) has a significantly higher hardness. The composition of the material based on special raw materials provides outstanding friction and wear characteristics as well as pressure resistance. This material exhibits an outstanding chemical and hydrolysis resistance for applications in mineral oil, biodegradable hydraulic fluids (HETG and HEES, etc) and water based fluids (HFA and HFB).
Compared to the S-ECOPUR standard material, X-ECOPUR S (TPU) is harder and therefore further improves sliding properties. X-ECOPUR S has a better extrusion resistance than the standard material and therefore seals made of this material can be used at higher pressure, assuming the same profiles are used. X-ECOPUR S is most suitable for poor lubricated working conditions. The material can also withstand dry-running depending on the overall service conditions.