Q. What would you recommend to assist me with my mold-cooling problems, which I attribute to major calcium buildup. Short of investing in big-money chemical injection units for my tower water system, or complete disassembly of the molds and machining out the lines, is there a product/solution that can be closed-loop cycled through these molds to remedy this issue?
—Jason E. Huckabee, vp, operations, Hayes Industries, Ltd., Sugar Land, TX
A. If you go outside our “slow-to-pick-up-technology” industry, there are some amazing technologies that are relatively inexpensive. To prevent calcium scale buildup, all you need is a water softener, which exchanges the calcium ions for something else. Some plants can get by with a $200 water softener from Home Depot, Lowes, etc.
Moving on to fix the plugged or restricted water channels:
—John W. Bozzelli,Injection Molding Solutions/ Scientiﬁc Molding, Midland, MIA.
Q. Please explain how different types of gels are formed and controlled in ﬁlm extrusion. —Global ﬁlm producer
A. Any defect in molten polymer is a “gel.” It could be a crosslinked gel, a black speck, or unmixed (unmelted) material. On barrier-type screws, if the melt channels do not have the proper aspect ratio and the channels are too deep, which will reduce the downstream velocity, cross-linked gels will build up and cause “showers.” For optical-quality film, a tighter barrier gap in the barrier section should be considered.
—Timothy Womer, global corporate technical advisor, Xaloy Inc., New Castle, PA