CR seals

CR stands for chloroprene rubber, a synthetic rubber and belongs to the elastomers of the R group, which are characterised by an unsaturated hydrocarbon chain. Probably the best-known trade name is Neoprene® In addition, the material is also traded as Baypren®.

CR Gasket

Available CR materials at Rehm Dichtungen Ehlers GmbH

We obtain most of our sealing material from the manufacturer Semperit in the form of rolls and sheets. Here we divide the material qualities into three ranges that are suitable for different applications.

Semperit quality

N9581 CR/SBR

Technical data sheet:

N9581 CR/SBR

Properties:

Hardness [Shore A] ISO 7619-1 65 +-5
Density [g/cm³] ISO 1183 Approx. 1.40
Tensile strength [N/mm²] ISO 37-S2 6
Elongation at break [%] ISO 37-S2 200

 

Approvals and certifications:

  • Corresponds to WDK guideline 2201
  • SVHC-free

Import qualities

CR/SBR 65 Shore

Technical data sheet:

CR/SBR 65 Shore

Properties:

Hardness [Shore A] ISO 7619-1 65 +-10
Density [g/cm³] ISO 1183 Approx. 1.4
Tensile strength [N/mm²] ISO 37-S2 4
Elongation at break [%] ISO 37-S2 250
CR/SBR 65 Shore with insert

Technical data sheet:

CR/SBR 65 Shore with insert

Properties:

Hardness [Shore A] ISO 7619-1 65 +-10
Density [g/cm³] ISO 1183 Approx. 1.4
Tensile strength [N/mm²] ISO 37-S2 4
Elongation at break [%] ISO 37-S2 250
CR/SBR light 65 Shore

Technical data sheet:

CR/SBR light 65 Shore

Properties:

Hardness [Shore A] ISO 7619-1 65 +-10
Density [g/cm³] ISO 1183 Approx. 1.5
Tensile strength [N/mm²] ISO 37-S2 5
Elongation at break [%] ISO 37-S2 300

The properties of CR as a sealing material

Chloroprene is produced by polymerising 2-chloro-1,3-butadiene. During the process, acid is added to the resulting dispersion, which is then cooled and dried.

The chlorine atoms in the material are inert, which makes the rubber stable. Furthermore, the vulcanised chloroprene has good mechanical and chemical properties. The material is resistant to embrittlement, ozone and weathering. The synthetic rubber shows good swelling resistance in mineral oils with an aniline point, in greases, many refrigerants and in water. CR is moderately resistant to swelling in mineral oils and low-molecular aliphatic hydrocarbons. In aromatics, the material is strongly swelling. Chloroprene is temperature-resistant in the temperature range -20° C and +120° C. The concrete specifications vary depending on the composition of the compound.

The advantages of CR at a glance

Chloroprene is characterised by a number of properties that make the material suitable for many applications. It is:

  • Resistant to: Embrittlement, ozone and weathering influences
  • Good swelling resistance to: mineral, vegetable and animal fats as well as mineral oils with a high aniline point, many refrigerants and water
  • strongly swelling in: Aromatics such as benzene, esters, ketones and chlorinated hydrocarbons.
  • Resistant to: dilute acids and salt solutions
  • flame-retardant

Furthermore, the elastomer has very good dynamic properties. The electrical insulating properties of polychloroprene are worse than those of NR, which is due to the polarity. Certain fillers increase the insulating properties. CR can therefore be used in the low-voltage range.

The sealing material cannot be cross-linked with sulphur, has only limited oil resistance and is not resistant to fuels or aromatic oils.

CR Resilience at a glance

Material designationOzone and weather resistanceOil and petrol resistanceAcid resistanceStrong basesWear resistance
Semperit N 9581conditionally stablenot durableconditionally stableconditionally stableNot suitable

Areas of application for CR seals

The material is used in various areas. Due to its slow crystallisation, CR is particularly used for seals in the automotive and other industries. Various seals made of this material are also used in air conditioning and medical technology. The shipping industry is also an important customer for this material, as it does not lose its function when it comes into contact with seawater.

We will be happy to answer your questions about whether CR is suitable as a sealing material for your purposes. Please contact our customer service, who will be happy to provide you with comprehensive advice.

FAQ

What are CR seals?
CR seals, which stand for chloroprene rubber, can be classified as elastomer seals and are characterised by an unsaturated hydrocarbon chain. CR SBR is also known under the trade name Neoprene® or the material Baypren®.
What are the properties of CR seals?
Due to the chlorine atoms present in the sealing material, CR is stable and, thanks to the vulcanised chloroprene, is characterised by good mechanical and chemical properties. In addition, the material is resistant to embossing, ozone and weathering as well as to dilute acids and salt solutions. Due to the increased insulating properties, CR can also be used in the low-voltage range. In addition, the material is considered flame-retardant.
What durability do CR seals offer?
CR gaskets are conditionally resistant to ozone and weathering influences as well as to acids and strong bases. Furthermore, seals made of CR have good swelling resistance to mineral, vegetable and animal fats.
Can CR seals also be equipped with self-adhesive?
CR gaskets can be equipped with a basic self-adhesive finish. In the first production step, the roll or sheet material is glued with a self-adhesive film in order to subsequently produce your self-adhesive CR seals.
Can CR also be purchased by the metre?
We use all our gasket materials to produce the right gaskets for you using our various manufacturing processes - waterjet cutting, plotting, punching. However, we are also happy to sell you CR by the metre, in strips or in the form of rolls and sheets.