DICHTOMATIK

Materials
For rotary shaft seals, different standard
and special materials are available for
the sealing lip (the elastomer
component), the metal insert and the
tension spring, depending on the type
and application in question.
The material used for the sealing lip is
usually given. The description of the
elastomer materials follows the
nomenclature used in DIN ISO 1629
and ASTM D 1418.
The basic material used in elastomer
for rotary shaft seals is synthetic rubber
manufactured in the chemical industry.
Elastomers differ in the basic polymer
from which they are made. The nomenclature
according to DIN ISO 1629
and ASTM D 1418 is shown in the table
below.
This procedure makes it possible to set
the required material properties and
thereby offer standard materials with
a wide range of uses, as well as
special compounds for highly specific
applications.
The rotary shaft seal is formed in a
vulcanisation process in which the
metal insert is bonded to the elastomer
element. The plastic rubber compound
assumes a rubbery-elastic state and
the rotary shaft seal attains its final
mechanical properties. The lip edge is
created by subsequent cutting or previously
in the moulding tool. Finally,
the tension spring is attached.
The finished material is made by mixing
the basic elastomer with the required
filler materials, softeners, processing
aids, vulcanisation agents, accelerators
and other additives.
Nomenclature for sealing
lip materials:
chemical description
Abbreviation
DIN ISO 1629 ASTM D 1418
Acrylonitrile butadiene rubber NBR NBR
Hydrogenated acrylonitrile butadiene rubber (HNBR) HNBR
Fluoro rubber FPM FKM
Ethylene propylene diene rubber EPDM EPDM
Silicone rubber VMQ VMQ
Acrylate rubber ACM ACM
DIN EN ISO 1043-1 ASTM D 1600
Polytetrafluorethylene PTFE PTFE
( ) = not listed in the standard
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