The two platen machine, i.e. two platen injection molding machine, eliminates the rear template relative to the traditional three-platen injection molding machine with fixed template, moving template and rear template.
The two-platen injection molding machine has appeared in the early stage of the injection molding industry, and its biggest difference lies in the different driving method of the mold closing part. Most of the injection molding machines in the industry adopt the three-platen type to close and lock the mold through the curved elbow. Compared with the three-platen machine, the two-platen machine cancels the tail plate and the curved elbow mechanism, and increases the quick mold shift cylinder and the holding brake device, together with the high-pressure clamping cylinder, to realize the function of quick opening and closing to establish the clamping function. In recent years, with the automotive industry’s demand for large tonnage, large space injection molding machine, two-platen machine gradually by the industry’s attention, has become a trend in the development of the industry, the major manufacturers have their own characteristics of the two-platen machine, in the plastics exhibition is also more common.
industry standard
As a class of injection molding machine, two-platen machine is also dominated by Europe and the United States and Japan, and steadily followed by China. The representative brands are: ENGEL, Demag, Mitsubishi, Famous Machine, Haitian, C, and so on. As the two-platen machine is only a change in the molding part, its parameters are basically the same as the same tonnage injection molding machine. According to the current industry information and exhibitions, the two-platen machine mainly adopts hydraulic drive or oil-electric hybrid drive, in which the large injection molding machine is mainly driven by hydraulic drive.
Factory Haitian 2800T three-platen injection molding machine as a reference, to understand ENGEL, MITSUBISHI two brands close to the tonnage of two-platen machine information.
Note: The following models are all standard machines. As the injection molding machine can be modularized and combined, the following parameters only represent different configuration requirements.
Item Unit Hydraulic Drive
two-platen machine two-platen machine three-platen machine
Brand ENGEL MITSUBISHI HAITIAN
Model DUO45050/27000 3000MMV MA28000/U
Screw diameter mm 200 200 200
Melting volume cm³ 28270 31400 35154
Injection speed mm/s 85 53 66
Injection rate cm³/s 2680 1675 2095
Injection pressure mpa 163 160 137
Plasticizing capacity kg/h 511 810 828
Screw speed r/min 74 59 50
Clamping force tf 2700 3000 2800
Tie bar spacing mm 2175*1750 2000*1800 1900*1750
Ejector force tf 38 70 43
Ejector stroke mm 400 350 450
Overall dimensions (L*W*H) m 16.5*5*3.8 15.4*5.5*3.9 18.9*3.92*5.5
Comparison of the above table, clamping force of 2800T or so, screw diameter ¢ 200 of the three brands of injection molding machine.
The first two columns of two platen injection molding machine basically reflects the current situation of the basic parameters of the large-tonnage two platen machine, compared with these two injection molding machine: ENGEL DUO45050/27000 advantage lies in the injection speed, the disadvantage is that the melting amount of glue is small; MITSUBISHI3000MMV advantage of the clamping force is large, the plasticizing capacity is strong, but the screw injection is slow.The difference and preference of equipment performance, combined with the modular matching of injection molding machines provided by each factory, has led to the development of specialized injection molding machines.
Comparison of the above two platen machine with the factory 2800T injection molding machine, 2800T injection molding machine parameters on the gap is not too obvious. Not considering the structural characteristics of each brand of injection molding machine, only from the length of the comparison of 3000MMV and MA28000/U body, the length of the size of 18.5% reduction.
Advantage of two-platen machine
The two platen injection molding machine due to the abolition of the rear template, and the melting part and the three platen machine is the same, so in the case of the same tonnage, the two platen machine space size is shorter than the three platen injection molding machine, on the other hand, due to the two platen injection molding machine basically adopts the fast cylinder directly acting on the movable template, the mold closing speed is relatively stable, and the mold closing speed is fast. When the mold is closed, the four guide columns are mechanically locked at the end, and the high pressure clamping cylinder at the end of the four guide columns locks the mold differently, which improves the parallelism of the template and reduces quality problems such as cloak, product deformation, and so on.
Space optimization: Due to the elimination of tail plate, the length of the same specification equipment is reduced by more than 20%.
Low resistance: The two platen injection molding machine replaces the green column with two guide rails, which effectively reduces friction, low wear and tear, and easy maintenance.
Fast mold closing speed: The mold closing speed is achieved by the fast mold transfer cylinder, which can optimize the empty cycle time by about 40% with the mold clamping.
Large space for mold opening and closing: mold opening and closing are not limited by the stroke of the curved elbow mechanism, and the length of the guide rail and the stroke of the quick-action cylinder can be enlarged to meet the special space requirements.
Better parallelism: through the guide cylinder differential clamping mode, the four guide columns are subjected to an average force, which can improve the parallelism of the mold bonding surface, and the plane locking force is uniformly distributed.
Longer service life: Compared with three platen injection molding machine, two platen injection molding machine uses quick cylinder for mold transfer, the pressure demand is not big, and four hydraulic cylinders are used for clamping, the force of hydraulic cylinders is even, the force line is short, the load on the hydraulic system is reduced, and the service life of the injection molding machine can be prolonged.
Disadvantages of the two platen injection molding machine
As the subsequent development trend of the two platen injection molding machine, in the current use of the following problems
1. Manufacturers to improve the technology: two platen injection molding machine in the domestic promotion and popularization has just begun, the domestic manufacturers have only launched two platen injection molding machine in recent years, the accumulation of technology and precipitation still need a long time to improve.
2. Control of production process parameters: relative to the three platen injection molding machine, two platen injection molding machine mold part of the parameters may be different from the three platen injection molding machine (depending on the manufacturer), which involves parameter adjustments and the use of experience needs to be accumulated.
3. Daily maintenance of equipment: three platen injection molding machine due to the unique structural design, the design concept of the different decisions of the equipment maintenance and maintenance work is different from three platen injection molding machine, for example, two platen injection molding machine on the level of the higher requirements of the machine, high-pressure clamping cylinders are more difficult to maintain.