SJSZ Series Plastic Conic Double Screw Extruder Machine
SJSZ Series Plastic Conic Double Screw Extruder Machine is widely
used for plastic pipe extrusion line ,plastic profile extrusion
line and plastic sheet extrusion machine line. It is used for
feeding,transporting, plasticing,melting plastic material and make
sure that plastic material out from different extrusion moulds.
SJSZ Series Plastic Conic Double Screw Extruder Machine is composed
of driven motor, gear reducer box, screw and barrel, feeder,
casting aluminum heater, cooling blower, vacuum pump, hopper and
Driven motor: It is main part of PVC pipe conic double screw extruder. We'd
better choose good brand AC type driven motor matching with
inverter controll for saving power running cost.
Gear recuder box: It is used for connecting motor and screw . As we know that motor
rotating speed is very high , if we connnect motor and screw
directly, screw rotating speed will be too fast, mixed PVC resin
material will be not melting and plasticing inside of barrel. So we
choose gear reducer box for connecting motor and screw for reducing
rotating speed of screw through size and teeth of gear changing in
the gear box.
Screw and barrel: It is most important part of conic double screw extruder. Quality
of PVC pipes main depends on this part. In normal, the surface of
screw should be paint double alloy for anti-wear due to mixed PVC
resin material including high percent of calcium carbonates. At the
same time, the design of screw structure is a key point for
extrusion capacity and quality, now design of screw is becoming
standardization and homogenization on the market, quality of screws
are stable for most suppliers now.
Feeder: It is used for feeding mixed PVC resin material into barrel from
the hopper on the top of extruder. This device is developing from
single screw feeding to parallel screw feeding process. Now more
and more PVC pipe making machine manufacturers adopt parallel screw
feeding device for avoding mixed PVC resin crack-bridging while
material transported into barrel on the bottom of hopper.
Casting aluminum heater: It is used for heating barrel and screw which ensure mixed PVC
resin material can be plasticizing and melting under the suitable
temperature when mixed PVC resin material comes into inside of
barrel and transported forward by screw.
Cooling blower : It is used for cooling barrel and screw. Due to casiting aluminum
heater is keeping heating, temperature of screw and barrel will be
increasing and if it excess setting temperature, cooling blowers
will be started to work for cooling barrel which avoid PVC material
resolved in the inside of barrel due to temperature is too high.
Vaccum pump : It is used for sucking the moisture of the mixed PVC resin
material which is under suitable temperature from the barrel in
order to make sure getting the final PVC pipes better quality.
Hopper : It is used for keep the mixed PVC resin material in the silo and
make sure material can be into barrel continuously. It is like a
material transport station.
Control Cabinet: It is used for control whole cornic double screw extruder running
by switchs or PLC programes according to different circuits control
What's the advantages of twin screw extruder over single screw
- Pumping efficiency is better and less dependent on the flow
properties of the material.
- Mixing is more efficient.
- The heat exchange rate from the barrel surface to the material is
faster and more uniform.
- Residence time is more uniformly distributed.
- Thanks to the possibility of flexible modular configuration of the
screw and the barrel, the twin-screw extruder is a more versatile
- High moisture and sticky materials can be handled. This is probably
the most important advantage, because it enables processing of
materials that could not be handled hitherto by single-screw
extruders. The introduction of twin-screw technology has resulted
in a significant expansion of the application of extrusion to foods
and the spectrum of extruded products.
- Self-wiping reduces the risk of residue build-up.
- Feeding problems with cohesive materials are less serious.
On the negative side, the relative disadvantages of the twin-screw
- Higher cost: both capital expenditure and the operating costs are
- Complexity: the twin-screw extruder is mechanically more complex
and less robust; consequently, the machine is more sensitive to
mechanical abuse (such as high torque).