Background:
RTP Company is a global leader in specialty
compounding. Specialty thermoplastic compounds from
RTP Company provide conductive, structural, wear
resistant, flame retardant, soft-touch and color properties
in over 60 engineering resins.
Needs:
To remain on the cutting edge of engineering plastic
compounds, RTP needed to expand their business with a
new research and development (R&D) center. As part of
the R&D center expansion, the plastic extrusion
equipment used within the R&D lab needed to have state
of the art technology.
Problem:
RTP needed to increase data acquisition capabilities on
their plastic extrusion equipment. The engineering effort of
new plastic compounds required a lot of intimate process
control information. The project time required to bring the
R&D center online was on a very tight schedule.
Solution:
The extrusion machine was specified to utilize 15
EZ-ZONE ST integrated control loop products to control
and monitor 15 zones on the extrusion machine. To meet
the desire for process and equipment related data
acquisition, the EZ-ZONE ST with digital communications
capability was identified to provide a system performance
data to a PLC (15 registers x 15 zones). The EZ-ZONE
ST delivered intelligent and distributed temperature and
power control switching to unburden the PLC. Since the
EZ-ZONE ST was an integrated control loop, it offered
greater ability to monitor system related information within
the thermal control zone.
EZ-ZONE ST value added benefits
identified by the customer:
Overall lower cost of ownership
Was simpler to build panels
Did not have to run wires from the back of the
machine all the way to the inside front door of the
panels
Less wiring and less termination was required saving
time and money during installation, as well as
improving the reliability of the system
A tight project schedule could be supported. Using all of
the following integrated functions resulted in less
engineering time and expense to specify the solution.
Limit control for over-temperature protection
Mechanical contactor for safety shut-down
Solid state relay for heater power switching
Heat sink
PID temperature control
Current measurement diagnostics
Less components to mount as panel space was limited.
Advanced tuning features EZ-ZONE ST offered
TRU-TUNE+, an adaptive PID control algorithm to
meet tight temperature control requirements in this
dynamic and challenging process application
Did not have to struggle with the time and expertise
required with writing PLC temperature tuning algorithms.
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