Extruded rubber seals support complex
cross-sections and a smooth surface finish. They include bulb, bulb trim, lip,
door, and accordion seals.
Rubber profiles
are made of elastomeric compounds and produced through molding or extrusion. Lengths
of standard rubber products are then custom-fabricated to meet application
requirements such as length.
Rubber molding processes such as injection, compression,
and transfer molding have their advantages, but extrusion supports the creation
of rubber profiles with complex cross-sections and a smooth surface finish.
As
a custom fabricator, Elasto Proxy stocks extrusions made of solid rubber and
sponge rubber, and can convert these standard products into specialty seals
that meet your specific requirements. Technical buyers
and product designers who download our Extruded
Rubber Products Catalog will learn that we keep hundreds of rubber
extrusions in stock.
The table of contents lists 19 different types of rubber
extrusions, but there are five that are labeled specifically as "seals". We
provide plenty of other industrial sealing products too, but let's focus on
these five types of extruded rubber seals in this article. For industrial
buyers and design engineers, it's important to understand the basics of bulb
seals, bulb trim seals, lip seals, door seals, and accordion seals. Let's take
a look.
Bulb Seals
Bulb seals have
an open, rounded or teardrop-shaped area that gives these distinctive-looked
rubber products their name. Some bulb seals feature other rounded shapes that
resemble a half-moon, or have a flat bottom. Physical dimensions vary, but
generally include height along with inner and outer diameter. Bulb gaskets are
often made of sponge rubber, and installed between a door and door frame in a
car or building. Softer bulbs made of materials such as EPDM foam help create a
watertight seal. In automotive and construction applications, bulb seals may be
attached by taping instead of mechanical fastening.
Bulb Trim Seals
Bulb trim seals
are dual durometer seals with bulb and trim sections. Typically, the bulb
portion is made of a medium-density sponge rubber such as EPDM. The trim or
retainer portion of the bulb trim seal is made of another material, such as
PVC. With their distinctive design and materials of construction, bulb trim
seals can offer resistance to water, ozone, sunlight, and temperature
extremes. These extruded rubber seals are also
available in weather-resistant, reusable, and often recyclable materials called
thermoplastic elastomers (TPEs).
Lip Seals
Lip seals
feature an edge or sealing lip and, in some cases, an opening. Often, they're
used to protect the bearing that supports a rotating shaft or bore. In addition
to retaining the bearing's lubricant, these rotary shaft seals help to prevent
the ingress of dust and other contaminants. Radial lip seals are used in
high-speed crankshaft applications for diesel and gasoline engines. They're also
used in other types of vehicles and with pumps, mills, and industrial equipment.
Elastomeric compounds vary in terms of material properties, so make sure to select
an oil-resistant rubber as required by your application.
Door Seals
Door seals are designed to fill the
gaps between doors and door frames in order to prevent wind, water, and weather
from entering vehicles or buildings. They're used in cars, trucks, residential
construction, and commercial and industrial facilities. Door seals such as
hatch seals are also used with fuel tanks, electronic enclosures, and rooftop
HVAC systems. This category of extruded
rubber seals includes some types of bulb seals, but also includes custom
weather stripping. Door seals are defined by application rather than by
geometric features or material composition, but are typically rectangular.
Accordion Seals
Accordion seals are extruded
rubber products that have folds like the bellows of an accordion. Consequently,
their physical dimensions are very different when stretched or compressed.
Accordion boot seals are used to weatherproof access points such as between a
truck cab and a trailer. Other types of accordion seals are also used in
automotive and transportation-related applications. Materials of construction
include EPDM rubber, and accordion seals may feature an internal spring steel
loom.
How Can We Help You?
Do you have questions about bulb
seals, bulb trim seals, lip seals, door seals, or accordion seals? Would you
like to see drawings of these extruded rubber products, and learn about other
rubber extrusions for industrial sealing? Let's get started. Download the Extruded Rubber Products catalog today.
| 
