Polyurethanes

Polyurethanes are thermoplastic elastomers that exhibit elastomeric characteristics over a wide temperature range while also displaying thermoplastic behaviour. They can be melted at high temperatures and processed using conventional thermoplastic processing methods. Polyurethanes offer outstanding mechanical properties, such as abrasion resistance.

ECOPUR

ECOPUR is a thermoplastic polyurethane elastomer (TPU) with exceptionally high abrasion resistance, low compression set, high physical properties and high tear strength. In sealing technology, ECOPUR is mainly used for U-cups, lip seals, wipers and packing, but it can also be used for dampers and other machine components. Products made from this material can be used in mineral oil, water up to 40 °C and biodegradable hydraulic oils such as vegetable oils and synthetic esters up to 60 °C. Depending on seal design and installation conditions, ECOPUR seals can be used up to 400 bar; for high pressures, SKF specialists recommend the use of anti-extrusion rings.

H-ECOPUR

H-ECOPUR is a hydrolysis-resistant thermoplastic polyurethane elastomer (TPU). It combines the technical properties of ECOPUR with high resistance to hydrolysis, which is otherwise rarely found in polyurethanes. It is stable in water up to +90 °C and has excellent stability in mineral oil. Because of its hydrolysis resistance, H-ECOPUR can be used in water hydraulics and in mining, tunnelling and press applications. H-ECOPUR is particularly recommended for use in fresh water and seawater, HFA and HFB fluids, biodegradable hydraulic fluids (vegetable oils and synthetic esters), and food products. H-ECOPUR is KTW approved and complies with FDA standards.

T-ECOPUR

T-ECOPUR (TPU) is modified for low-temperature applications. Its properties are similar to those of ECOPUR, but the minimum operating temperature is extended to -50 °C. T-ECOPUR is therefore particularly suitable for harsh climatic conditions and frozen-goods processes.

G-ECOPUR

G-ECOPUR is a hydrolysis-resistant cast polyurethane elastomer (CPU) with properties similar to H-ECOPUR, particularly in terms of chemical stability. G-ECOPUR can be used with the same hydraulic fluids as H-ECOPUR. G-ECOPUR is generally used for seals with diameters from 540 mm to 4,000 mm as a single piece, and for larger sizes using our special welding technique.

G-ECOPUR 54D

G-ECOPUR 54D is a cast polyurethane (CPU) with high material hardness that is particularly suitable for large-diameter applications. It has chemical and mechanical properties comparable to G-ECOPUR, but with higher Shore hardness and improved friction and wear properties.

X-ECOPUR series

X-ECOPUR polyurethanes are harder grades of ECOPUR.

Compared with standard materials, the harder grades exhibit almost the same tensile strength and elongation at break at a significantly higher 100% modulus, as well as greater tear strength. Compression set, for example, remains at approximately the same level as standard materials. X-ECOPUR variants have higher extrusion resistance than conventional polyurethanes and therefore enable higher pressure at the same geometry. X-ECOPUR grades have increased wear resistance, extended service life and a greatly reduced tendency to stick-slip compared with standard polyurethanes.

X-ECOPUR

The composition of X-ECOPUR (TPU) provides exceptional friction and wear properties as well as high pressure resistance. The material is therefore highly suitable for use as a composite seal, for wipers operating in demanding applications, and for engineered plastic parts requiring high elasticity and superior flexibility.
Because of its exceptional extrusion resistance, seals made from this material can operate at higher pressure levels and with larger extrusion gaps than seals made from standard polyurethanes and PTFE compounds.

X-ECOPUR H

Compared with the standard H-ECOPUR grade, X-ECOPUR H (TPU) has significantly greater hardness. Its composition, based on special raw materials, provides exceptional friction and wear properties as well as pressure resistance. This material has outstanding chemical and hydrolysis resistance for use in mineral oil, biodegradable hydraulic fluids (HETG and HEES, etc.) and water-based fluids (HFA and HFB).

X-ECOPUR S

Compared with standard S-ECOPUR material, X-ECOPUR S (TPU) is harder and therefore provides even better sliding properties. X-ECOPUR S has better extrusion resistance than the standard material, so seals made from this material can be used at higher pressures when the same profiles are used.
X-ECOPUR S is particularly suitable for poorly lubricated operating conditions. Depending on the overall service conditions, the material can also withstand dry running.