Injection-press Machine

Injection-press machine

The 4-Axis parallelism control and Injection volume control(MPPS: Meiki Pre-Press System) of MDIP series makes it possible to mold large and thick-wall product with uniform thickness.

On injection press molding mode, material can flow in the cavity of mold with less stress and resin flow pressure within the mold can be reduced considerably. Then, molding procuct with less distortion/warping is provided. At the same time, since the injected material is quickly pressed under the control of an accumulator before it is cooled, the material remains fluid. The combination of a fluid material along with the extention effect permits the production of large, thin-walled moldings.

1)Advantages of injection press molding
Smaller clamping force : Thin products with large projected areas can be molded with smaller clamping forces, thanks to the extention effect given by high-speed pressing during injection with the mold open.
Uniform thickness : The 4-axis parallelism control ensures uniform thickness even for unevenly loaded moldings produced with side gate dies such as transparent window plates.
Less distortion/warping : A lower and more uniform pressure used by the molding press has reduced the residual stress.
Composite(glued)molding : A lower resin flowing pressure does not deform the mating surfaces.
2)Best practice
●Engine under cover

●Uniform thickness and less distortion/warping

Projected area = 5700cm2/ Material: PP
Thickness=1.3~2.0mm Temperature: 260℃
Center gate Mold temperature :60℃

Injection press molded

Press pressure = 650 ton
Standard injection molding process

Clamping force = 850 ton
Injection pressure = 1700kg/cm2

●A5 size Chassis of PC (A5 size) : M200C-DM

●Glued molding- Copper foil(35um)

Material: ABS/PC/PBT+CF15%

●Door trim

●Glued molding(Fabric)

A lower resin flowing pressure within the mold doesn’t spoil the appearance and other properties of glued products.

3)Injection press processes

4)Injection volume control
In the injection press molding process, a variation in injection volume directly leads to a variation in product weight/thickness. Immediate causes of injection volume variation include a variation in molten resin density and in the closing motion of the check valve on the screw head. The MEIKI uses the Meiki Pre-Press System to remove those causes.

The MPPS obtains a constant resin density by pre-loading the screw barrel.Pre-loading is accomplished by activating the shutoff valve at the nozzle tip and then forwarding the injection screw until the check valve on the screw head closes. At this point the trapped resin inside the barrel is under a constant pre-injection pressure and hence a constant density. The screw position after pre-loading is taken as the starting point of the injection stroke by the MPPS.Therefore, with a constant resin density and a fixed, programmed injection stroke, the injection volume remains constant after every cycle.
  MPPS control

  Effects of MPPS control(measurements under the same conditions)