IMM 8/97

We currently have a tool that has stainless core pins running on a cylinder. The wall section is thick in one area, producing a void in the part. The only way we have found to reduce it is to run an obnoxiously long cycle time. Water is not really an option in the area, the cylinder runs on an angle up from the box The material being used is 6/6 nylon, 25 percent glass, which kind of rules out aluminum-bronze. If anyone has any suggestions on how to keep the pin cool, I would appreciate it.

Have you tried Noren thermal pins or upgrading to an air core, filling it with gas? It works; we have been using this technology for some time on cores that are too small for water lines-.250 inch in diameter and 4 inches long.
-Tony Mendoza, Talleres Mendoza, Zapopan, Jalisco, Mexico, (52) 3 627 1735.

Noren thermal pins would be very effective. Is there a problem getting water to the back of the pin? If so, you may be able to air cool the pin. This has been effective in some designs. The only constraint becomes how to get the "free" end of the pin to circulating air.
-S.Eskridge, Owens-Brockway, Bridgeport, CT, 203-394-6079.

We are using a material called Anviloy 1150. Anviloy 1150 is a perfect material for core pins because it cools four to seven times faster than other materials used to make cores.
-J. S. Colegrove, Brill Cast Inc., Grand Rapids, MI, (616) 532-1209.

Thermal pins seem to do the trick in places where you cannot get the waterlines to cool the mold. If your mold construction allows the addition of thermal pins, then it should help in reducing your cycle time. One of the suppliers for thermal pins is Noren in California and its phone number is (415) 322-9500.
-V. Sirani, BASF Corp., Wyandotte, MI, (313) 246-5093.

Stainless is very poor in heat transfer. I would use a pin made from 940 bronze and have it Armoloy coated to keep the glass-filled material from washing out the pin. Also, have a smooth hole that the pin fits in so the pin will transfer heat into the mold.
-J.Wiens, Magnum Mold, Nixa, MO, (417) 725-5465.