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this inquiry the last week…
I have a single cavity mold with a
part varying in wall thickness from 3 to 5 mm. The part is warping near the
transition of the thin to thick section. What can I do to overcome this problem?
warpage yours is caused by differential shrinkage. In this case it sounds like
you have an uneven temperature gradient throughout the wall thickness of the
start by checking your coolant temperatures. If the cooling lines enter on the
thin side of the part and exit on the thick… the water temperature will already
be higher on the exit side of the mold. I suggest hooking up your cooling lines
on the thick side of the part first.
the entering and exiting water temps to ensure the difference is not to great.
If your exiting water temperature is fairly greater than your entrance
temperature you may want to consider getting a more powerful chiller.
with a stronger pump and higher volumetric throughput will have better cooling
uniformity and water temperature throughout the mold.
You may also
want to try increasing the packing pressure to reduce the amount of material
shrinkage, increase the pack time until the part weight no longer increases, or
profile your packing pressure to obtain a more uniform shrinkage across the