Plastic Extruders
Plastic extruders are machines which melt and shape raw plastic pellets or
flakes into channels, tubes, sheets or shapes. Extruders are fairly simple machines which use the physics of friction
and pressure to partially melt, or "plasticize" raw plastic material,
squeezing the molten material through a shaping die, or mold, at the outputting
end. Gravity feeds plastic pellets or flakes through a hopper down into the
extruder's enclosed screw conveyor channel. This conveyor moves the raw
plastic along towards the opposite end, shearing and heating the plastic; electric
heaters built into the conveyor often aid the melting process. The molten plastic
is formed into a specific profile as it is pushed, or "extruded" by
the die at the open end. The newly formed plastic profile is instantly cooled
with cold water, pulled through by a series of conveyors and cut to appropriate
lengths.
Extruded
plastics manufacturers use plastic extruders to make plastic profiles, plastic
channels, plastic
rods, plastic
tubing and plastic
sheets, all of which play a vital role in virtually every industry, from
consumer to automotive to medical. Plastic
channels and profiles can have almost limitless length and are manufactured
into window profiles, building siding and trim, gutters and channels, sealing
sections, hoses, curtain rods, tubes, pipes, drinking straws and many other common
products. Extruded plastic
sheets are used in packaging and
are often thermoformed into consumer products and packaging. Plastic
rods and thick gauge sheets are machined by automotive, aerospace and construction
industries into parts for close tolerance applications. The extrusion process
is highly customizable and is capable of high volume production as well as short
runs, making plastic
extrusion one of the most diverse and economical methods of plastic fabrication.
Plastic extruders can extrude any thermoplastic material (that is, plastic material
which changes its form under various levels of heat), including HDPE, LDPE, PETG,
PVC, butyrate, vinyl, polypropylene and polystyrene. Plastic
extrusions are responsible for the production of everyday necessities like
PVC pipes, indoor and outdoor window trim, sealing bars, siding, plastic gutters, plastic
sheeting,
toys, recreational accessories, and much more. Virtually every industry uses plastic
extrusions, including the automotive, marine, packaging,
plumbing, construction and medical industries. Since the extrusion process uses
a continuous output of smooth, thoroughly heated and mixed material, extruded
plastics seldom have bubbles or inconsistencies, and they are therefore valued
for their structural integrity and consistent, precise profiles.