60 Years of ZSK Twin Screw Extruders
Anniversary of Coperion’s high-performance ZSK extruder series
The ZSK twin screw extruder, the “forefather”
of all twin screw extruders, celebrates its 60th
anniversary this year. Werner & Pfleiderer,
known nowadays as Coperion GmbH, delivered
the first co-rotating, closely intermeshing
ZSK twin screw extruder in 1957 – exactly
60 years ago. Since then, the ZSK extruders
have undergone a transformation that was
inconceivable 60 years ago – from what would
now be considered relatively simplistic co-
kneaders with a throughput rate of 170 kg/h
to sophisticated, high-performance processing
machines for a variety of applications in the
plastics, chemicals, food and pharmaceutical
industries. They are manufactured with screw
diameter sizes ranging from 18 to 420 mm and
achieve throughput rates from 200 g to 125 t/h
for polyolefins.
Four years from the first prototype to serial
production
In 1953, Werner & Pfleiderer acquired an exclusive
license from Bayer in Leverkusen, Germany. The
work was started by Rudolf Erdmenger and Walter
Meskat at the IG plant in Wolfen in 1943. In 1945
Rudolf Erdmenger continued the work as part of the
“High-Viscosity Technology” group and developed the
fully self-wiping profile for co-rotating intermeshing
screws. This was the inception of the ZSK twin screw
extruder, which remains functional over a wide
range of viscosities or frictional properties of the
processed material. The prototype of this machine
invented by Erdmenger was still equipped with
vertically arranged screws, unlike the ZSK twin screw
The prototype built by Erdmenger – the “forefather”
of all ZSK twin screw extruders – was equipped with
a cardan-shaft drive system and numerous vent caps.
Image: Coperion, Stuttgart
12 TUBE NEWS October 2017