Page 71 - Plastics News September 2016
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PRODUCT NEWS
Nordson’s BKG® HiCon™ located on each piston. Each pair of cavities is positioned
V-Type 3G screen changer so that they can ?lter their respective melt streams, until
the piston removes one of the cavities from the process
Nordson Corporation has enhanced the design of its to remove contaminant buildup by means of back?ushing.
patented “power back?ush” V-Type screen changer, In normal operation, polymer is ?owing through all four
creating a more compact and ef?cient system whose cavities. While one of the cavities is changed, the other
continuous operation eliminates downtime in extrusion, three remain in the process. In addition to the two screen-
bearing pistons, there is a single hydraulically actuated
pelletizing, displacement piston that operates during back?ushing.
and recycling. When the differential pressure across the screen changer
Nordson’s increases to a pre-set level because of contaminant buildup,
BKG® HiCon™ the back?ush sequence for all cavities will be started
V- Ty p e automatically. For each cavity, the displacement piston
3G screen retracts, creating a reservoir of ?ltered molten polymer.
changer uses This material is hydraulically compressed and discharged in
a hydraulically reverse direction, back through the screen, carrying away
powered contaminant for removal from the system. The sequence
backflush is performed for each cavity one after the other.
system to automatically remove contaminant while
maintaining extrusion throughput and keeping ?ow and China's Tederic launches
pressure constant. Operationally, the new screen changer all-electric presses in India
is more streamlined and ef?cient than the earlier V-Type
system from Nordson, with a 30% shorter back?ush cycle. Tederic Machinery Co. Ltd. of Hangzhou, China,
There is a higher degree of automation resulting from introduced its all-electric injection molding machines in
an autonomous parameterizing of the entire back?ush the Indian market at an industry forum. The company,
procedure and of the screen change procedure, including ranked the ninth
filling and venting. All of the filtration area of the largest injection
combined four screen cavities is available for production molding machine
while ?lling of the displacement-piston cylinder takes maker in China,
place. Two outlets for back?ushed material are located said it established
on the bottom of the unit, with discharge automatically a separate
controlled by the movement of the screen-bearing business division
pistons. In comparison with the earlier V-Type system, for all-electric
the height of the new V-Type 3G screen changer has been presses at the
reduced by 30%, permitting a lower extrusion height; a end of 2015 and
single displacement piston is used for back?ushing instead commercialized
of having one for each screen cavity; and hydraulic piping the DE line. The
has been optimized. company said it also revised its marketing position from
“leading technology” to “standard machines.” As more
“The HiCon V-Type 3G screen changer provides up to 200 and more Chinese press makers enter the all-electric
backflushing cycles before screens must be changed, segment, Tederic said, every company has its own take
reducing operating costs and with four screen cavities and focus. Tederic said its machines can meet customer
making a large ?ltration area available in a comparatively needs for high speed, precision, energy ef?ciency and
small housing, only minimal amounts of material are lost quietness. Tederic announced early in 2015 that it was
in back?ushing. In the HiCon V-Type 3G screen changer, forming a press manufacturing joint venture in India
melt ?ow from the extruder is split at the entry side with its Indian distributor.
and guided to the four screen cavities, two of which are
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