Plastic Machinery Comparisons
Comparing Twin Screw Extruders and Single Screw Extruders
Twin screw extruders
Twin screw extruders are the classic machines used in
compound
production. That is when two or more ingredients are mixed and
extruded n order to produce a pellet.
Twin screw extruders are particularly useful in the production of rigid
PVC and wood fiber blends.
Twin screw extruders with co-rotating, intermeshing, segmented screws can
be considered as ideal machines for the preparation of polymer compounds
with high percentages of fillers, reinforcing fibers or with particularly
heat-sensitive (frame retardants) or shear-sensitive (glass fibers,
microspheres) additives. A machine which is equipped with a vacuum pump
for degassing, with cylinder cooling and screw cooling will be preferred
for composite compounding. A volumetric dispenser to supply the material
is required, as well as a stainless steel hopper.
Single screw extruders
Single screw extruders are useful machines to be used in production when
a pure polymer is used such as HDPE.
A single screw machine will produce plastic wood or other profiles from
regrinding chips with out the need for pre pelletizing.
Single screw extruders can be supplied with all kinds accessories:
automatic gravimetric feeders, vent vacuum units, heat and pressure
controllers, heat exchangers, melt pumps, static and dynamic mixers,
microprocessor control systems, as well as with a wide range of screw
geometries for different materials and products. A machine equipped with
an air cooled barrel will be preferred for producing HDPE products.
Rebuilt equipment saves money on plastic recycling and plastic lumber
equipment
"Old iron is good iron." That is a saying often heard among experienced
plastic recyclers. What it simply boils down to, is that the
sophistication incorporated into many modern plastic
recycling machines does not lend itself to recycling plastic into plastic
lumber or
composition.
Rebuilt use equipment is more forgiving of the
changes in the type of recycled plastic that the recycler
encounters in real production. A good rebuild on plastic
lumber equipment will produce recycling machinery that
custom built to customer specifications with
many new
parts that costs only 50% of the cost of new equipment. Plastic lumber
machinery can be assembled to customer specifications for a specific
application. Recycled plastic lumber requires different types of equipment
for different applications. Cierra Industries of Auburn NY will build
special plastic lumber machinery lines to customer specifications from
used, rebuilt or new machines.
The rebuilder takes the following steps when rebuilding plastic recycling
or plastic lumber machinery.
-
Disassembles the recycling machinery
-
Inspects and replaces all worn parts
-
Installs new drives and electronics
-
Installs new barrel and screw on extruders
-
Sand blasts and paints all components of machinery
-
Reassembles all machines and components
-
Test runs all machines and components
By the time all of these steps are taken the recycling machinery line or
plastic lumber equipment is a custom built line which is warranted and
built to the customers exact needs at about half the cost of new
machinery.
If you have further questions please address them to
pvan123@aol.com.
Questions concerning equipment for plastic recycling equipment or plastic
lumber will be answered as soon as possible.
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