Background
information: Extruded
rubber seals are made by forcing the uncured rubber through
a die while it is under heat and pressure. This uncured rubber
is then vulcanized, i.e. heated, to cause a chemical reaction
which cures the rubber. However, the term "rubber extrusion"
is used loosely to refer to many elastomers in addition to natural
rubber --- elastomers such as EPDM, EPR, NBR, neoprene, nitrile
(Buna-N), silicone, FKM fluorosilicone, Kalrez®
and urethane. Extruded rubber seals
can be manufactured with a hardness value between 40 and 90
durometers.
In
addition to o-rings and seals, a rubber extrusion process is
used to manufacture rubber components such as tubes, shapes
(C, E, H, L, etc.) and forms (rounds, rectangles, trapezoids,
etc.). These components are often used in industries such as
the chemical, automotive and manufacturing industries without
further manufacturing processes applied to the components. However,
the extruded components can also be ground, milled, drilled
or turned to create other products such as gaskets, seals, caps,
motor mounts and suction cups.
Extruded
rubber o-rings come in both AS568 standard sizes and in
custom sizes; we manufacture them in both inch and metric sizes.
If you need non-standard extruded rubber seals or o-rings we
will need to make a tool made according to the specifications
for your application. The accuracy and quality of the tool is
critical for the production of quality parts. The tool will
be rated in a tolerance class rating system that goes from F1
to F4 for different areas of the tool. A rating of F1 is the
highest and means that the area should have a finish up to 10
micro-inches, with no visible tool marks. The lowest rating
of F4 means that the area will have a satin like finish. Extruded
rubber seals, o-rings and components can have a small amount
of flash material which will need to be trimmed.