Our materials and delivery times

xpress seals can supply sealing components made from high-quality standard materials plus various PTFE compounds, PEEK, compounds of polyamides and polyimides, PETP, etc. Many of our materials are available in FDA-approved grades.

Please see the table below for exact details or send us an enquiry. We will be happy to advise you.

Our most popular materials are water-stable red polyurethane with a Shore hardness of 95A and black polyurethane (70D), nitrile butadiene rubber (NBR) with 85 Shore A, virgin white foodstuffs-compliant polytetrafluoroethylene (PTFE) and a PTFE compound with 40% bronze. Our many years of experience go into all these materials. For instance, together with our partners, we have also defined standard materials such as a PTFE compound filled with 23% carbon and 2% graphite. And apart from the standard materials, we are also very familiar with materials for low-temperature applications, for example. Those include, in addition to PTFE + compounds, an elastomer such as T-NBR (low-temperature NBR) with 85 Shore A and TT-PU, a low-temperature polyurethane with a hardness of 94 Shore A. Both materials can be used in temperatures down to -50 °C.

Furthermore, our range also includes elastomers for foodstuffs-compliant and drinking water applications meeting the German KTW recommendation. All these special materials are also available for large-format seals with quick delivery times.

Water-stable polyurethane is the most interesting development in materials in recent years; more and more textile-reinforced NBR moulded seals are being replaced by this new material. Water hydraulics has become popular and has established itself among users. Biodegradable liquids are used. The challenge for original equipment manufacturers is to select the right material for these liquids. Hydrolysis-stable polyurethane and good old NBR are suitable for the majority of these applications.

The advantage of polyurethane over NBR is its excellent tribological properties: low coefficient of friction, high wear resistance and very high extrusion resistance. PTFE and its compounds are possible alternatives; PTFE + 15% glass fibres + 5% molybdenum disulphide and PTFE + 40% bronze have proved worthwhile in past applications. Virgin PTFE is still very popular for anti-extrusion rings in conjunction with an NBR O-ring. Here, too, budget-priced alternatives in the form of one-piece components in HPU, which fit in the same housings, are already available. And we should not forget the so-called hard polyurethanes with, for example, 57 and 72 Shore D, which are replacing PTFE wherever this is technically possible. That means that calibration – often time-consuming and expensive because of the installation tools needed – is unnecessary.

*In principle, we can supply any material freely available on the market which can be processed on a lathe. Likewise, we can recommend one of the materials from our range that will suit the chemical specification of your medium.

Simply ask us.