TYPES OF EXTRUDERS

“Extruder” is the equipment which carries out the process of extrusion.
Depending on the mechanism, by which the rubber compound or the
plastic formulation is forced through the orifice, extruders canbe
classified into two:
RAM type Extruders
SCREW type Extruders

RAM type Extruder
Ram Extruders:

Not frequently used
Only for very specialised extrusions
Only short lengths depending on the barrel capacity
Relatively high power requirement,No plasticating action inside the barrel

Screw type Extruder

Screw Extruders:
Most popular form of extruders
Suitable for heavy duty continuous runs
Relatively low power requirement
Very long continuous profiles
Plasticating action inside the barrel

Ram Extruders:

Not frequently used
Only for very specialised extrusions
Only short lengths depending on the barrel capacity
Relatively high power requirement
No plasticating action inside the barrel

Depending upon the temperature of feed, extruders
can be classified as:

Hot feed extruder

Cold feed extruder

Depending upon the feed stock, extruders can be
classified as follows also:

Rubber extruder

Plastic extruder


Opposing Extruders

Direct face to face combinations of extruders, the
outputs from both the extruders being conveyed into a
common head block which is properly designed to effect
the required combination of the outputs of the individual
extruders through suitable preforms and inserts

Piggy back Extruders

Combinations of extruders, where the the individual
extruders are all positioned on one side, one over the
other and all discharging the outputs in to a common
head where the flow take place in suitably designed
channels and ultimately combine in the preform to give
the required extrudate.

Depending upon the design of barrel , Cold feed
extruders can be divided into two :

Plain barrel extruder

Pin barrel extruder


Common applications of Rubber and Plastic
Extruders



RUBBER EXTRUDERS
Tread and side wall extrusions in tire making
Tube Extrusion
Extrusion of Slugs, Rods, Hoses etc
Straining of Tube and Bladder stock
T Head Extruders for insulating cables, wire coating, coating of wire
Fabric

PLASTIC EXTRUDERS

Extrusion of tubes, pipes, rods etc
Wire covering, cable sheathing
Flat sheet extrusion, Flat films
Package strapping, tapes for sound and video recording
Tubular film
Fibers and monofilaments