May 29, 2019 10:53 PM PDT
[url=https://www.nbstarlite.com/product/plastic-parts]Plastic
Injection Parts[/url] molding is a process in which custom molded component
manufacturers heat a polymer until it reaches a highly plastic state and forces
it to flow under high pressure into a mold's cavity to solidify. Manufacturers
then remove the molded part, or molding, from the cavity. The process produces
discrete components that are almost always net shape, reducing the need for the
surface finishing. A mold may contain more than one cavity, allowing custom
injection molding companies to produce multiple moldings each cycle. The
production cycle time ranges between 10 and 30 seconds .
Injection Molds and
Molded Components
Injection molding is a widely used molding process for
thermoplastics. Some thermosets and elastomers are injection molded when
equipment is modified and operating parameters allow for the cross-linking of
materials.
It requires designing and fabricating a mold whose cavity has the
same geometry as the original part. It must also allow for part removal. Part
sizes range from 50 grams (2 ounces) to 25 Kilograms (55 pounds). Heavier items
made using injection molding include automobile bumpers and refrigerator
doors.
The mold determines the part of the shape and size. It's also the
special tooling in injection molding. When making large, complex parts, a mold
may cost hundreds of thousands of dollars. When it comes to smaller parts,
manufacturers can create molds with multiple cavities, Adding to its cost.
Incidentally, injection molding is most economical for large production
quantities.
Injection Molding Products: Equipment and
Process
Equipment
Injection molding equipment originates from metal die
casting processes. An injection molding machine has two main
components:
Plastic injection unit
2. Mold clamping unit
Plastic
Injection Unit
In essence, an injection unit’s primary functions are to melt
and homogenize a polymer before injecting it into a mold cavity.
The
injection is similar to an extruder. It contains a barrel that a hopper with a
supply of plastic pellets feeds from one end. Inside the barrel is a screw that
turns to mix and heat the polymer. The screw of the acts as a ram that quickly A
non-return valve near the screw's tip prevents the melted material from flowing
backward along the screw's threads.
Later in the molding cycle, the screw, or
ram, returns to its former position. Because of the screw's dual action, it's
referred to as a reciprocating screw, which also identifies the machine type.
Older injection molding machines use a simple ram without screw However, the
reciprocating screw design's superiority has promoted its popular adoption in
today's custom injection molding companies.
Mold Clamping Unit
The
clamping unit’s primary functions include:
Holding the two halves of the
mold in proper alignment
Keeping the mold closed during the injection
process by applying a clamping force strong enough to resist the injection
force
Opening and closing the mold at the appropriate times during the
molding cycle
Clamping units have two platens—a fixed and movable platen—and
a mechanism for translating the movable platen. The mechanism is like a power
press that a hydraulic piston or mechanical toggle device operates. Larger
machines have clamping forces of several thousand tons.
[size= medium][url=https://www.nbstarlite.com/product/plastic-parts]Plastic
Injection Parts[/url] molding is a process in which custom molded component
manufacturers heat a polymer until it reaches a highly plastic state and forces
it to flow under high pressure into a mold's cavity to solidify. Manufacturers
then remove the molded part, or molding, from the cavity. The process produces
discrete components that are almost always net shape, reducing the need for the
surface finishing. A mold may contain more than one cavity, allowing custom
injection molding companies to produce multiple moldings each cycle. The
production cycle time ranges between 10 and 30 seconds .
Injection Molds and
Molded Components
Injection molding is a widely used molding process for
thermoplastics. Some thermosets and elastomers are injection molded when
equipment is modified and operating parameters allow for the cross-linking of
materials.
It requires designing and fabricating a mold whose cavity has the
same geometry as the original part. It must also allow for part removal. Part
sizes range from 50 grams (2 ounces) to 25 Kilograms (55 pounds). Heavier items
made using injection molding include automobile bumpers and refrigerator
doors.
The mold determines the part of the shape and size. It's also the
special tooling in injection molding. When making large, complex parts, a mold
may cost hundreds of thousands of dollars. When it comes to smaller parts,
manufacturers can create molds with multiple cavities, Adding to its cost.
Incidentally, injection molding is most economical for large production
quantities.
Injection Molding Products: Equipment and
Process
Equipment
Injection molding equipment originates from metal die
casting processes. An injection molding machine has two main
components:
Plastic injection unit
2. Mold clamping unit
Plastic
Injection Unit
In essence, an injection unit’s primary functions are to melt
and homogenize a polymer before injecting it into a mold cavity.
The
injection is similar to an extruder. It contains a barrel that a hopper with a
supply of plastic pellets feeds from one end. Inside the barrel is a screw that
turns to mix and heat the polymer. The screw of the acts as a ram that quickly A
non-return valve near the screw's tip prevents the melted material from flowing
backward along the screw's threads.
Later in the molding cycle, the screw, or
ram, returns to its former position. Because of the screw's dual action, it's
referred to as a reciprocating screw, which also identifies the machine type.
Older injection molding machines use a simple ram without screw However, the
reciprocating screw design's superiority has promoted its popular adoption in
today's custom injection molding companies.
Mold Clamping Unit
The
clamping unit’s primary functions include:
Holding the two halves of the
mold in proper alignment
Keeping the mold closed during the injection
process by applying a clamping force strong enough to resist the injection
force
Opening and closing the mold at the appropriate times during the
molding cycle
Clamping units have two platens—a fixed and movable platen—and
a mechanism for translating the movable platen. The mechanism is like a power
press that a hydraulic piston or mechanical toggle device operates. Larger
machines have clamping forces of several thousand tons.[/size]