Click Image to Enlarge
Unlike most large two-platen presses, Milacron's updated Maxima line builds tonnage in the center instead of on the four tiebars, reportedly minimizing platen deflection. The updated clamp has longer guided length, extended stroke and daylight, removable ejector box, and faster dry cycle.
An improved line of large two-platen injection presses offers new sizes plus greater speed, educed maintenance, more operator-friendly design, and added flexibility for a range of molding requirements. The upgraded Maxima line from Cincinnati Milacron ranges from 1125 to 6600 tons. They are designed to accommodate the growing popularity of multi-component injection, stack molds, extra-large mold carriers, and ability to handle everything from flat to deep-draw parts. They also provide easier access for maintenance. The new presses are also "global" ma-chines in that they will be built identically in the U.S., Germany, and China, except for electrical standards, safety provisions, and other local preferences.
The newest Maxima line replaces the MM and ML series and adds four new sizes—1460, 2025, 2990, and 4385 tons. Previously available sizes have been adjusted for today's global markets: 1125, 1300, 1820, 2330, 2585, 3315, and 6600 U.S. tons.
These presses retain design elements of the Maxima line. One of the most important features is the short-stroke central clamping cylinder on the moving platen. This produces 50% less platen deflection than most other two-platen presses, which clamp at the ends of the four tiebars and tend to "wrap" the platen around the mold, according to chief engineer Ron Hertzer. The result, he says, is less mold wear and improved part quality. Another key feature that differs from most other two-platen presses is full support of the tiebars from end to end. In particular, a rigid frame supports the ends near the moving platen.
Support for the platens carrying larger molds has been increased on the new models. Large "skates" under the moving platen and attached clamp-cylinder not only provide longer guided length but are also adjustable—a reportedly unique feature that ensures parallelism for heavy molds.
Here's what else is new on the updated Maxima models:
The Maxima series also boasts increased injection rates and screw speeds. The new 4400-tonner has two 854-oz injection units that each can shoot 11.5 oz/sec of PE and plasticate 1500 lb/hr of PE or 1100 lb/hr of PP.
Also new is an extra hole in the standard stationary platen to accommodate a second injector for hard/soft overmolding and two-color parts.
Milacron accommodated user requests by providing a much larger conical hole in the stationary platen to provide easier access to purgings and the nozzle tip. Milacron also moved the rapid-traverse cylinder back into the clamp area so that it does not extend into the injection area.
The hydraulic pumps are shielded so that sound levels reportedly are much lower at the operator station. New Maxima models also have more platform area for the operator and more room in the "cattrack" for mold utility lines.