|
Information Page Links:
Featured Rubber Molding Manufacturers
About Rubber Molding
Rubber Molding Terms
Rubber Molding Associations
Rubber Molding Resources
Trade Shows
Featured Rubber Molding Articles
More Articles
|
|
About Rubber Molding
Rubber molding is a process that produces a useable
molded rubber product. Rubber products are made from uncured rubber or
elastomers. An elastomer is any material with sufficient resilience or
memory for returning to its original shape in response to pressure or
distortions. Some commonly used examples of elastomers are styrene butadiene
rubber (SBR), ethylene propylene (EPDM), butyl, hypalon, viton, latex
rubber, silicone rubber, nitrile and neoprene. SBR and nitrile are used
for their petroleum hydrocarbon resistance, and EPDM for its ability
to remain unaffected by ozone, sunlight and weathering. Butyl is water,
alkali, steam and oxygenated solvent resistant. Silicone can be used
as both a liquid or solid, and is very durable, and neoprene has a good
burn resistance and is flexible. Rubber and elastomers can be derived
from natural sources to produce latex and polyisprene, although they
are mostly synthetic, produced through highly controlled chemical processes.
Rubber is an excellent material for situations that require a material
to give and return to its original shape. Required information for purchasing
molded rubber products include rubber mold shape, rubber mold size and
working temperature range for the rubber. The hardness, which is the
amount of resistance to distorting forces, is also an important consideration.
Specific industries that benefit from custom rubber molding services
are automobile, appliance controls, lawn and garden, sporting goods,
medical, electrical, government and recreational. These industries and
others benefit from the many different products that can be created by
rubber molding services.
While there are variations in specific rubber molding methods, all rubber
molding services use heat and pressure to form molded rubber products.
The four most common methods in the rubber molding process are injection
molding, compression molding, blow molding and transfer molding. Each
of these rubber molding methods is different, but all involve pouring
liquid rubber material into a mold where it is cured in an oven and cooled,
using pressure, air or temperature to mold, thus creating the finished
product. Some examples of molded rubber parts include rubber grommets,
rubber tubes, rubber shock mounts, rubber stoppers, rubber sheets, rubber
hoses, rubber bumpers, rubber washers, rubber grips, rubber caps, rubber
gaskets and rubber seals.
There are many factors involved in custom rubber molding that affect
tolerances. One is shrinkage, where the rubber product reduces in size
in the mold after cooling to room temperature. The amount of shrinkage
is determined before production and accounted for appropriately in the
size of the rubber mold. Another is trimming and finishing, where the
excess rubber that protrudes from the mold parting lines is removed.
Distortion is an important consideration, as well, because the shape
of rubber is flexible and can be changed according to temperature. For
this reason, rubber parts have to be stored at a certain temperature
to avoid distortions and thus, ruined products.
Featured
Articles
http://www.findarticles.com/p/articles/mi_m3617/is_1993_Annual/ai_14028364
http://www.apmhexseal.com/news_pdfs/tech_designer_seals.pdf
Types of Rubber Molding
- is a less-common process of placing
a hollow tube between the two halves of a blow mold. The blow mold
then closes, pinching off the bottom half of the tube, and air is injected
into the top, forcing the material outwards to the walls of the blow
mold.
- is a process that compresses the rubber material
in a mold under heat and pressure to achieve the desired shape.
- , or Ethylene-Propylene-Diene Monomer, is an elastomer.
- involves melting rubber in an injection unit and
then injecting it into the mold where it stays until after cooling
when the finished product is ready.
- is formed through pressing melted rubber into dies.
- are rubber rings inserted into a hole in sheet metal to protect cords or electrical wires from the abrasion.
- are used to prevent leakage at joints.
- are flat pieces of rubber used for a variety of purposes.
- refers to long, hollow cylinders used to transport liquids and gases.
- involves building a "piston and cylinder"-like
device in the mold and squirting the rubber into it through small holes.
The mold is then closed and under hydraulic pressure the rubber or
plastic is forced through a small hole into the cavity where it cures.
|
|
