Page 49 - Plastics News September 2018

FEATURES

‡ Set up screen;
‡ Calibration screens;
‡ Interlocks and alarms;
‡ Startup checklist;
‡ Main screen;
‡ Data logging.
Review the startup procedure:

‡ The main disconnect;
‡ Temperature settings and heat-soak times;
‡ Startup water-cooling systems and lube-oil pumps;
‡ Turn on downstream equipment;
‡ Fill the feeders;
‡ Start the main drive at low speed;
FRQÀUP WKDW WKH PRWRU URWDWLRQ LV FRUUHFW SULRU WR UXQQLQJ Start the feeders at low rate;
the machinery under load. ‡
‡ Monitor torque;
Material will be required to put an initial load on the Engage the pelletizing equipment;
extruder. Have plastic on-site, so the technicians can ‡
put a load on the extruder when it’s ready for an initial ‡ Ramp up extruder and feeders to appropriate rate;
WHVW 5XQ DOO WKH PDFKLQHV EHORZ ORDG DW ÀUVW ZKLOH ‡ Increase the pelletizer speed to match rates.
FKHFNLQJ IRU DQ\ DEQRUPDO VRXQGV YLEUDWLRQ ÁXLG OHDNV Turn on vacuum pump and/or open valve to the
HWF :KHQ WKH WHFKQLFLDQ LV FRQÀGHQW DOO LV 2. WKHQ WKH system.
system can be run up to higher rates.
‡ Review how to clear an upset condition and clean/
2SHUDWLRQDO 4XDOLÀFDWLRQ maintain the vacuum pump.
‡ Monitor feed throat for feed limitations.
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the system is working properly it’s time to tackle operator ‡ Discuss various processing tips.
WUDLQLQJ ,W·V YHU\ GLIÀFXOW WR WURXEOHVKRRW HTXLSPHQW ‡ Review the use of the special tools and preventive
issues while training people at the same time. Operator items to be noted daily, monthly, and annually.
training is best handled independently after the system The objective for the installation of any twin-screw
is up and running.
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‡ Review customer-generated SOPs; well-designed installation plan, and maintain a timeline
‡ Review equipment and systems manual; and budget. The end-result is a fully operational and
documented system. This doesn’t happen by chance. The
‡ Review FAT and IQ documentation where required;
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‡ Equipment operation conformity check-out; SKDVH RI D SURMHFW EHFRPH D ´OLYLQJ GRFXPHQW µ :KLOH
‡ Review the normal value on the gauges, indicators and this up-front work can be tedious and time consuming at
the zone controllers in a manual/discrete operator the beginning, it ultimately minimizes miscommunications
interface; and saves time and money.
‡ &RQÀUP WKH LQLWLDO FDOLEUDWLRQV DQG HVWDEOLVK D PHWKRG 7XUQNH\ LVQ·W DOZD\V WXUQNH\ :KLOH WKH WHUP PD\ EH
to collect the data that will be used to maintain an ÁLSSDQWO\ XVHG WR GHVFULEH WKH LQVWDOODWLRQ LQ UHDOLW\
operating baseline; there are many responsible parties that must contribute
Review touchscreen/HMI operation: to ensure that a twin-screw system is operational on time
and producing a quality product. No matter what, it’ll be
‡ Access level (operator/engineer/administrator);
a lot of effort.
‡ Heat-up, interlock/bypass;

49 September 2018 Plastics News