MITSUBISHI HEAVY INDUSTRIES PLASTIC TECHNOLOGY CO., LTD.

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Mold clamping force of 2,300 tons - Electric-drive injection molding machine “2300em”
      Realization of the world smallest space in the class

We have developed a super size electric-drive injection molding machine, Model “2300em”, which has a mold clamping force of 2,300 tons that promises a higher productivity in the molding of large size plastic parts for automobiles or others. This model is ranked just below the Model 3000em debuted in the end of 2004 with the world largest 3,000 tons mold clamping capacity, and has realized also the world smallest body in the class (machine length 13.7 m).

The “2300em” model has been developed using the same techniques featured on the 3000em that realized a mold clamping capacity of 3,000 tons first in the industry; namely, our original high torque, low rpm and high capacity DD servo motor*1, electrically driven clamp opening-closing / electrically driven split nut opening-closing system*2, UB screw with MD melter special to automotive part materials*3, among others. Thanks to these features, the cycle time has been reduced by approx. 30% compares with conventional hydraulic machines in the same class so that it contributes great deal to enhance the production efficiency and cost reduction in the molding of large size plastics parts such as the instrument panel and bumper for vehicles, large size LCD TV frame and many others for home electric appliances.

Another merit of “2300em” is that it has achieved remarkable improvements in saving of both energy and space owing to employments of our unique 2-platen mold clamping mechanism*4 and hybrid type electric-drive system*5. In terms of energy saving, the electric power consumption has been reduced by approx. 60% while, in terms of space saving, it has realized the world smallest machine length for electric machines in the same class. Moreover, the low noise type eco-pump system*6 and the large injection capacity DD servo motor have realized low noise operations to improve the workplace environment. Newly designed mold plates has opened up a way to introduce the “new center press type mold plates*7 (patent pending, one of standard specifications for 3000em)” that eliminates problems of flash and thus reduces costs of products.

Some of pressing needs in molding large size parts like bumpers for vehicles include the “high cycle” and “reduction of wall thickness”. Model “2300em” is designed to adapt effectively to high-speed molding with such functions as the high-speed injection (large capacity DD servo motor), high-speed clamp opening/closing (electrically driven system to open and close mold clamp/split nut), high-speed plasticizing (electrically driven high speed screw revolving mechanism), among others. Its multi-point gate charging (sequential gate control)*8 and other features support moldings of parts with thinner walls with a greater degree of allowance.

Taking the introduction of this “2300em” as an opportunity, we will strive positively to deploy sales of the super size electric-drive injection molding machines not only to large size automobile part and related industries but also to those of large size home electric appliance parts.

*1
Large capacity DD servo motor
A servo motor, developed by our own technology, allows connecting the injection shaft ball screw directly to the motor shaft. This motor eliminates the use of belt, reduces noise / dust and maintenance items, and enhances the response performance at the startup.

*2
Electrically driven clamp / split nut opening / closing system
With the control of ball screw and servomotor being disposed in optimum condition, higher response clamp opening and closing have been realized. Dry cycle of clamp opening and closing has been drastically reduced compared with conventional hydraulic machines.

*3
UB screw with MD melter
Mixing component with a polygon cross section installed at the end of screw enhances the kneading performance at the high cycle molding without sacrificing the plasticizing capacity.

*4
2-platen type mold clamping mechanism
Mold clamping mechanism consists a pair of fixed and movable plates.A system having no third plate, which is common to the toggle mechanism. We have been employing this system for good many years because of its space saving capacity.

*5
Hybrid electric-drive system
A system that switches the electric and hydraulic drives during injection molding processes. Hydraulic system is operated for the mold clamping process, nozzle touch process, or others, which require to control powers accurately, while the electric system takes care of the injection, plasticizing and ejector processes, in which the accuracy in speed and pressure as well as reliable repeatability are vital.

*6
Low noise type eco-pump system
A pump system that combines a hydraulic pump and a servo motor in order to use the hydraulic drive after raising the revolution speed to a specified value only when required in the molding processes.

*7
New center press mold plate
Mold plates have been redesigned to effectively prevent curved deforms on the surface of mold plate and restrict burrs from occurring under a higher internal mold pressure condition.

*8
Multi-point gate charging (Sequential gate control)
A method that allows charging resin reliably under low molding pressures using a number of resin charging gates provided in the mold. Since these gates are opened orderly in the resin flowing direction, the molding can be carried out under much lower pressures.



"2300em" specification table
Model Units 2300em
340
Injection Screw diameter mm 135
Screw L/D 22
stroke at ejector section mm 675
Theoretical injection capacity cm3 9,660
Injection mass Polystyrene (PS) g 8,890
Polyethylene (PE) 7,150
Maximum injection pressure MPa
(kgf/cm2)
177(1,800)
Maximum holding pressure 147(1,500)
Injection rate cm3/sec 1,780
Injection horsepower kW
(PS)
316(429)
Plasticizing capacity (PP) kg/h 610
Screw RPM rpm 132
Nozzle touch force kN (tonf) 98(10.0)
Clamping Clamping method Electro-hydraulic
Mold clamping force kN (tonf) 22,555(2,300)
Mold opening force 1,549(158)
Mold opening / closing speed (mold close / mold open) m/min 55
Platen size (H x V) mm 2,550×2,300
Min. mold dimension 1,300×1,100
Tie bar space (H x V) 2,000×1,650
Clamping stroke, maximum 2,700
Daylight, maximum 3,500
Mold thickness 800~1,700
Ejector Ejector force kN (tonf) 392(40)
Stroke mm 350
Speed (forward/reverse) m/min 12.5
General Heater capacity kW 68.4
Machine dimensions (L x W x H) m 13.7×4.5×3.6
Center height m 1.95
Machine mass ton 135
  • 1. The numeric values in this table are subject to improvements or changes without notice.
  • 2. Plasticizing capacity is based on standard test conditions performed by Mitsubishi.
  • 3. Injection mass, injection ratio, and plasticizing capacity differ depending on the resin used and molding conditions.
  • Please contact us to discuss using the machine at the maximum capacity.



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