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CONTRIBUTOR
Ryan Pohl is founder of Praeco Skills LLC.
FOR MORE INFORMATION
Praeco Skills LLC / 616-951-2133
ryan@praecoskills.com / praecoskills.com
Go over the idea of true net during the training on spotting
tools. Be sure to put emphasis on proper spotting of slides
and lifters.
Hot runners. Apprentices need a general understanding
of hot runners. Technicians that have advanced beyond the
apprentice level can continue to learn about hot runners,
which represent a specialized area. A general understanding
for apprentices includes the ability to recognize the various
systems, components and applications. The apprentice should
understand why and when to use a hot runner, the function
of its heaters, thermocouples, hot drops and tip styles. For an
apprentice, understanding a tip's bearing surfaces and its cool-
ing issues is critical.
Hydraulics. Many plastics injection molds incorporate
hydraulics, so apprentices must learn when and why they
are used, recognize the various cylinder types and know how
to choose the proper cylinder for the application at hand.
Additionally, apprentices should be able to identify and explain
hydraulic sensors, switches, mounting methods, rod connec-
tions and fittings, and they should be able to use basic hydraulic
formulas.
Runners and gating. Apprentices should be able to recognize
the different types and applications of runners and gates. Also,
they should understand cavity filling, which requires a knowl-
edge of gate geometry. And, learning about the various runner
types and geometries will help them understand plastic flow.
Mold types. Apprentices will likely see an array of work
come through a shop, so training should include an overview
of the various mold types and their applications. Examples
include three-plate, two-shot, stack, unscrewing, thermoform
and blow molds.
LEARN MORE
For more from Randy Kerkstra's series, "The Designer's Edge,"
visit short.moldmakingtechnology.com/rkerkstra .