Page 38 - Plastics News July 2018

FeAtures

The table on the previous page summarizes typical benefits the part, iMFLUX’s ability to pack while it fills eliminates
that result from these differences. unnecessary material, reducing part weight. Cycle time

Four case studies was reduced by 13%.
Case Study 4: A PP automotive component was run in
Case Study 1: A polycarbonate medical part was converted an eight-cavity tool on a 550-ton hydraulic machine. It
to the iMFLUX process. The customer was experiencing
high scrap rates due to an imbalanced 16-cavity mold with previously ran on a 50-sec cycle, but after the iMFLUX
process was integrated to the press, the cycle time
hot-runner valve gates, causing intermittent short shots.
iMFLUX reduced scrap rate from more than 10% to less was reduced by 8 sec, resulting in a 20% throughput
improvement. As described in Case Study #3, simultaneous
than 0.2% by improving the balance from part to part. This
is due to constant-pressure filling. Every part experiences pack and fill created a 14% pressure reduction and a 1%
part-weight reduction. On top of this, iMFLUX’s ability to
the same pressure and the geometry of the part tells the
machine how to continually profile velocity, resulting in dynamically absorb viscosity changes reduced the scrap
rate from 18% to 0.2%.
consistent packing conditions. On top of eliminating short
shots and gaining 48% improvement in cavity balance, iMFLUX Process Benefits
the cycle time was reduced by 30%. In this example the Low constant pressure
existing all-electric injection machine was retrofitted to • Lower clamp tonnage
run the iMFLUX system.
• Less retained stress
Case Study 2: For a PP household-cleaning implement, iMFLUX • Uniform stress (less warp)
was brought in during the design phase for new molds and • Lower melt temperatures
presses. Knowing the benefits of pressure reduction, the • Less gate blush
mold was designed to maximize the capabilities of the • Less flash
technology. The part previously ran in a servo-hydraulic • Less cavity-to-cavity variation in multi-cavity & family
500-ton machine with eight cavities and a 52-sec cycle. molds
The new iMFLUX mold and system allowed the use of a • Less material degradation
conventional hydraulic 400-ton machine, while expanding
cavitation by 50% to 12 cavities and reducing the cycle Pack-as-it-fills
by 21%. Together, that resulted in a 91% throughput • Faster cycles
improvement. Even with adding four cavities and reducing • Fewer sink marks
cycle time, the overall peak injection pressure was 30% • Stronger weld lines
lower than with the conventional process. While iMFLUX • Improved surface finish
is effective on retrofitted machines with existing tooling, No hesitation
this case shows there are substantial benefits to designing • Reduced flow lines
new molds specifically for the iMFLUX process. • Improved thin-walling
Case Study 3: A PET packaging component was run in a • Higher L/T capability
four-cavity mold on a hydraulic press retrofitted with • Smaller cold runners
the iMFLUX technology. The new process achieved a 16% Cavity-pressure response
throughput increase over the conventional process. On • Lighter parts (1-3%)
average, retrofitted machines with existing molds achieve • Reduced flash
15% to 25% throughput improvement. However, the • Automatic adjustment for viscosity
iMFLUX process also reduced the cavity imbalance from • Real-time adjustment for blocked cavities
6% to 0.8%, nearly halved the amount of pressure needed • Actuate sequential valve gates
to fill the part (from 1079 bar to 622 bar), and reduced
the average part weight by 0.48% while maintaining all • Not affected by leaky check ring
dimensional specifications. By packing as the part is • Not affected by worn barrel
filled, pressures can be reduced. Furthermore, while a Gene Altonen has been the Chief Technology Officer of
conventional process fills at a high velocity and then packs iMFLUX in Hamilton, Ohio, since 2015. (Plastics Technology)

Plastics News July 2018 38