New clamping, injection, and screw designs enhance the new MD-S6000 series of all-electric machines introduced by Niigata Machine Techno Co., Ltd., of Japan, at the International Plastics Fair in Tokyo in November. (Niigata is represented here by DJK Global Group—Niigata Plastic Machinery Div., Wood Dale, Ill.) The enhanced versions come in 55 and 110 tons; an 85-tonner will be next. Features include clamp support on linear bearings rather than the tiebars for reduced friction. The clamp design and support system are said to improve platen parallelism up to 18%. A new barrel and nozzle temperature controller helps to stabilize melt temperatures. The injection unit has a new screw for more uniform melting, a direct-drive motor for screw rotation, and “G Screw System” software that allows the the molder to use the same injection set-up parameters on machines of different tonnage, so long as the screw diameter is the same (stroke is automatically adjusted). Niigata also developed a new injection unit for the series that allows for long pack and hold times without overloading the servo motors. Its LP (Long-time Pressure) unit has low-friction linear guides and digital load cells for more accurate positioning. The machine now also has wider platens and can handle multiple injection units. Niigata also developed a new screw for use with the LP process. The “OA” screw allows the molder to produce uniform melt at uniform temperature when running a full shot utilizing the maximum injection stroke. Conventional screws may not have enough time to plasticate pellets at the back of the screw into uniformly melted polymer at the front, leading to unmelt. Mixing is said to be improved with the optional OA design, without changing the L/D. Niigata also introduced a new series of all-electric vertical machines with a two-station rotary table for insert molding. Tiebar spacing has been increased about 20%. The new MDVR85X 82.5 ton press has a vertical clamp with vertical or horizontal injection unit. It also has a more rigid toggle clamp, stiffer platen and larger, servo-driven rotary table. (630) 361-6020 • www.niigata-us.com
Niigata Engineering Co.
Daiichi Jitsugyo America Inc.
939 AEC Dr. Wood Dale, IL 60191-1143
Phone (630) 875-0202 Fax (630) 875-0422
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