We
are all aware the importance of rubber as an indispensable material that has
use in virtually every kind of industrial application. Rubber's unique
property of resilience makes it extremely suitable for critical applications
involving sealing, shock absorption and fluid transportation. Out of various
rubber processing methods, extrusion takes its place as a popular choice.
One of the reasons being the neat and uniform way through which extruded
rubber profiles are produced. Typical examples of rubber extruded profiles
include continuous sheet, tubing, seals, gasket profiles and weathering
stripping.
Rubber Extrusions can be of three types Sponge rubber extrusion, solid
rubber extrusion and cellular rubber extrusion. Features of the rubber
extruded profiles that makes them very popular include:
- Resistance to ozone
- Heat and cold resistance
- Flex-crack resistance
Important Considerations in Rubber Extrusions
When thinking of rubber extrusion, consideration is to be given regarding
the physical and mechanical properties of the material. Question is to be
asked is regarding its appropriateness for the environment where it will be
used. Typical Properties like permeability, aging, tensile strength,
hardness, flexibility and speed of recovery from deflection tends to vary
with different materials and this needs to be carefully weighed against the
respective benefits or weaknesses.
Applications of Extruded Rubber Products
Extruded rubber products are used in numerous industries. Some of the major
industries are shown here.
- Building Industry
Profiles in sponge and solid forms are a favourite with the building
industries. Other applications include Rubber seals for doors and
windows.
- Construction Industry
Applications include expansion joints for roads, bridges and runways.
- Automotive Industry
A wide range of rubber extruded profiles are used in automotive
applications. Typical shapes like continuous length or jointed frames
for use in weather strips and underhood applications. Some of the most
popular uses include :-
- Sponge Door Weather Strips
- PU Coated or Flocked Run-Channels
- Solid Windscreen Rubbers
- Tubing and Protectors
- Railways
Profiles for doors, windows and gates.
- Medical Industry
Rubber thread as in catheters.
- Specialised Application
A very special application of extruded products is in providing
intumescent solutions for positive pressure code requirements.
Materials for Extruded Rubber Profiles
There are many types of rubber that are suitable for extrusion process some
of them are listed here:
Comparing the properties of Rubber extrusion material
The following table takes a hard look at physical and chemical properties
of rubber material used in the extrusion process.
| Material |
EPDM |
Neoprene |
SBR |
SBR |
Silicone |
| Durometer Range (Shore A) |
45-90 |
45-90 |
45-95 |
50-80 |
45-90 |
| Tensile Range (P.S.I) |
500-2500 |
400-4000 |
500-3000 |
500-3000 |
200-1500 |
| Elongation (max.%) |
600 |
75-600 |
600 |
600 |
700 |
| Compression Set |
Good |
Good |
Good |
Good |
Good |
| Resistance to abrasion |
Good |
Good-Excellent |
Excellent |
Excellent |
Poor-Fair |
| Tear Resistance |
Fair |
Good |
Excellent |
Fair |
Poor |
| Solvent Resistance |
Poor |
Poor |
Good |
Poor |
Poor |
| Oil Resistance |
Poor |
Fair |
Fair |
Poor |
Poor-Fair |
| Aging Weather - Sunlight |
Excellent |
Good |
Good |
Poor |
Excellent |
| Adhesion to Metals |
Fair-Good |
Fair-Good |
Good-Excellent |
Excellent |
Good |
| Resilience - Rebound |
Good |
Good |
Good |
Good |
Good |
Buyers Zone
As a smart buyer dealing in rubber extruded profiles you need to ask
the following important questions before venturing to procure extruded
profiles.
- Whether the properties both physical and mechanical of the
desired material are conducive to the environment, where it will be
put to use.
- Properties like aging, tensile strength, hardness, flexibility,
permeability and speed of recovery from the deflection shows a
tendency to vary in different materials, so there is a need, that
they be weighed against the respective benefits/weaknesses that will
result from using such materials.
|
Shapes of Rubber Extruded Products
Coming to the shapes of rubber extruded profiles a variety of shapes are
possible with distinctive features. Some of the popular shapes are described
here:
 Applications
include Wiper, Seal, Filler Strip, or even as Edging. Profiles can be in
cut pieces, coil form, long straight lengths, form-cured lengths etc.
|
 Angle
Extrusion Applications include Wiper, Seal, Filler Strip, or even as
Edging. Profiles can be in cut pieces, coil form, long straight lengths,
form-cured lengths etc. Bumper Strip Profiles can be available in the
form of coil, long straight lengths, form-cured lengths, to cut pieces
also. |
 Generally
used as a Filler Strip, Seal, or even as a Glazing Seal. Profiles are
easily available in the form of coil, long straight lengths, cut pieces
to even form-cured lengths. |
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