Custom Plastic Injection Molding Terms You Need To Know

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20 Common and Uncommon Plastic Injection Molding
Terms
Greenleaf.biz [phone] 310 Bussell Ferry
Road, Lenoir City, TN 37771
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20 Common and Uncommon Plastic Injection Molding
Terms
Learn the Plastic Injection Molding lingo to
better communicate with engineers, project
managers and mold technicians. It is our
pleasure to produce the annual guide to over 200
injection molding industry terms. Download the
entire ebook here. To be fair, thats a lot of
words, so we asked our mold techs to select 10 of
the most common. Combine the slightly more
obscure terms to the list of common ones, and
youre ready for a factory tour and maybe even a
project design discussion!
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10 Injection Molding Terms Mold Techs Use Daily
BURN When the air temperature inside the mold
exceeds the flash point of the plastic, a burn
mark is made. If something is burned in
molding, it shows evidence of thermal
decomposition through some discoloration,
distortion and localized destruction of the
surface of the plastic. EJECTOR CONFIRMATION
SWITCH A switch used to prevent mold damage by
detecting if the ejector plate does not fully
return to home position. FLASH Extra plastic
attached to a molded part along the parting line
or other shut-off locations in the mold.
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10 Injection Molding Terms Mold Techs Use Daily
GUIDE PINS Devices that maintain proper
alignment of the core and cavity while the mold
closes. These are also called leader
pins. JETTING A turbulent flow of resin from
an undersized gate, or thin section, into a
thicker mold section. This is opposed to a
laminar flow of material progressing radially
from a gate to the extremities of the
cavity. KNIT LINE A mark on a molded piece
made by the meeting of two flow fronts during
molding. It can also be called a weld line.
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10 Injection Molding Terms Mold Techs Use Daily
NOZZLE TIP (REMOVABLE) A replaceable tip that
installs into the end of the molding machines
nozzle. Nozzle tips must be matched to the mold
surface (for sealing off high injection
pressures), and to the orifice of the mold
sprue. PLASTICIZE To soften a material and
make it plastic or moldable either by means of a
plasticizer or the application of heat. PURGING
Cleaning one color or type of material from the
cylinder of an injection molding machine by
forcing it out with a purge compound, or with
the new color/material to be used in subsequent
production. SHORT SHOT A molded part produced
when the mold has not been filled completely.
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10 Obscure Injection Molding Terms You Should Know
AGING Refers to the change of a material with
time under defined environmental conditions,
leading to either improvement, or the
deterioration of certain properties. CAST To
form a plastic object by pouring a fluid
monomer-polymer solution into an open mold where
it finishes polymerizing. CONDUCTIVE PLASTICS
Materials that allow a current or charge to
travel through it. Conductive plastics are hybrid
polymers that are electrically conductive or
static dissipative. These plastics are
engineered, using additives such as copper,
silver, aluminum, carbon black and carbon fibers,
to have conductivity characteristics.
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10 Obscure Injection Molding Terms You Should Know
CURE To change the physical properties of a
material by chemical reaction to make it more
stable functional. The process may include
condensation, polymerization, or
vulcanization. ELASTICITY The property of a
material by virtue of which it tends to recover
to its original size and shape after
deformation. FLAME RATING An internationally
accepted plastics flammability testing standard
created by Underwriters Laboratories. INSERT
An integral part of a plastic molding consisting
of metal, or other material, which may be molded
into position or may be pressed into the molding
after the molding is completed.
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10 Obscure Injection Molding Terms You Should Know
LIM (LIQUID INJECTION MOLDING) A process used
to produce silicone parts using an injection
molding machine. The silicone is a thermoset
resin, and is injected as a two-part liquid into
a heated mold where the silicone rubber is
solidified (vulcanized). NOTCH SENSITIVITY The
extent to which the sensitivity of a material to
fracture is increased by the presence of a
surface in homogeneity such as a notch, a sudden
change in section, a crack, or a scratch. Low
notch sensitivity is usually associated with
ductile materials, and high notch sensitivity
with brittle materials. PERMANENT SET The
increase in length, expressed in a of the
original length, by which an elastic material
fails to return to original length after being
stressed for a standard period of time.
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About GreenLeaf Industries
GreenLeaf Industries is an ISO 9001 registered
manufacturer that consistently adheres to all its
standards to provide our clients with consistent,
reliable, quality automotive and industrial
plastic parts. We are an American injection
molding company, unafraid to compete in the world
market and determined to succeed. Established in
1999, we take pride in our high-quality
craftsmanship and superior customer service.
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Greenleaf.biz [phone] 310 Bussell Ferry
Road, Lenoir City, TN 37771
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