Die cleanout and color changes are simplified with a flat-die clamping system that mechanically clamps and releases die halves in reportedly less than a minute. The new system consists of a series of hydro-mechanical clamps positioned along the backline of the die manifold in the same locations occupied by the body bolts in a conventional die. The traditional bolts hold the upper and lower halves of the die body together, offsetting the 3500- to 4000-psi forces inside the die. Removing them requires 1650 to 1950 Nm (1200 to 1300 ft-lb) of torqueÃwork often done with manual tools. With this new system, the operator of the boltless die simply flips a switch to start a 30 second unclamping or reclamping process. The system is only available on new dies.
The boltless die is said to increase machine uptime and operator productivity for extrusion processors and Web converters who do frequent split-and-cleans, and also to encourage more frequent cleaning by other operators, ensuring higher levels of product quality and consistency.
According to the manufacturer, the boltless die is most useful for processors of custom sheet, high-clarity goods, and degradable resins. It's also said to be beneficial for processors who change materials or colors frequently, or process heat-sensitive resins with degraded byproducts that must be cleaned out of the flow channel to prevent defects. Manufacturers of electronic and medical products or optical-grade film and sheet needing frequent buildup removal from the die are also said to benefit.
In addition to eliminating the need to loosen and tighten body bolts, the boltless die permits online splitting and cleaning using a cart designed to hold the die and the hydraulic and mechanical components of its clamping system. The cart installs on any typical extrusion line and can accommodate dies of different widths. The combination of online cleaning and mechanized clamping is meant to reduce total split-and-clean time, so that most machine downtime is devoted to the die cleanout itself.
Extrusion Dies Inc.
Chippewa Falls, WI