Page 36 - Platics News June 2022
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how far on the tool the band should go a shift in material ow.
on. Also incorporate some form of loca- Before starting up the extruder, map the
tion for the opening of the band. When die heat. Using a pyrometer, check the
the band’s location is changed, the tem- temperature on the nal die plate in the
perature changes, causing a shift in ma- four directions: North, East, South, and
terial ow. e velocity of the material West. Any variation beyond 2° F will re-
will ow toward the path of least resist- quire a recheck of the ve heater band
ance, the hottest portion of the tool.
principles cited above. Don’t do tooling
If the position of a heater band and its work until the heat transfer is veri ed by
opening changes, the temperature in Fig. 04 means of temperature measurement.
that portion of the die changes, causing
36 PLASTICS NEWS June 2022
