Injection Molding China: How Does It Work?

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Injection Molding China How Does It Work?
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We see the results of reaction injection molding
everywhere! Otherwise known as RIM, you will find
the technology in everything from auto parts and
tractors to machine parts and tools. The
equipment and the products to produce these items
have only been around for sixty years or so, and
businesses across the US have been in operation
for over thirty years.
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This happened in the 1980's when the automotive
industry began to use more reaction injection
molding to make gaskets for panel and radial seal
air filters. Because polyurethane, the material
used in Injection Molding China is synthetic, it
also has a lower cost than many natural metals
that were the former materials to make some of
these automotive and machine parts.
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How Reaction Injection Molding Works
So many things that we encounter in everyday life
are made out of polyurethane. Do we ever think to
wonder how they came to get that shape? It had to
come from a mold, and a substance had to get into
that mold somehow, and thats how reaction
injection molding gets its name. 
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The reaction occurs when two liquid compounds a
polyisocynate component and a resin mixture are
fed from separate tanks into a common mixing area.
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From the two temperature and pressure controlled
tanks, they are rapidly shot into the mix
chamber and undergo a chemical change, and the
mixture then flows into the mold. For smaller
parts, this can take just seconds per shot of
material and the part can be out of the mold in
30-60 seconds, complete. Larger products, such as
automotive bumpers, car hoods and even fenders
can also be made with reaction injection molding.
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Variability of Reaction Injection Molding
Two different techniques for RIM technology are
used to produce items. The first is open cast
molding. This is typically less expensive to
produce, for the urethane mixture can be hand
mixed or put into a urethane dispensing machine
and then poured into the mold. 
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The other method is centrifugal casting,
described above, and is used when the part needs
to be built from the center.
These days many parts can be made with different
colors and have a varying degree of hardness and
flexibility using Injection Molding China. The
four primary colors of red, blue, yellow and
black, and the non-color, white, are most likely
available from most reaction injection molding
manufacturers. 
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Also, depending on the quantity ordered, you can
have custom colors mixed to produce the perfect
match for your product.
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The hardness and durability of an item may be
adjusted as well. Bowling balls, a very hard
substance, are made with RIM. 
Products produced with RIM have a durometer
rating which shows the hardness of the material
on a number scale, with the higher the number,
the harder the material. Along with the number, a
letter is added to describe how dense the
material is. 
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This is shown as an A for a lower density to a D
for a high density product. A 72D is much more
hard and dense than a 28A. Injection Molding
China allows the variation of how hard and how
dense a particular item needs to be. The size of
the product would be another consideration, and
various manufacturers have different availability
of sizes of tooling, or molding equipment.
Whenever you see a hard, plastic-like urethane
material, it may very well have been fashioned
with reaction injection molding.
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NICE Rapid Tooling Limited
E-mail enquiry_at_nice-rapidtooling.com Tel 86
760 89962989 Fax[phone] Website
www.nice-rapidtooling.com