The model production process for molding machine

① closing mould: closing foaming mould

When we adopt the big bead material of package material, seam smaller than pre-foaming bead radius remains on the parting part. It is  in favor of compressed air discharge from air slug and gap in the material feeding process and in favor of bead’s quick filling in the mould cavity. When heating by steam, the air and condensate water in the beads can be discharged from mould cavity from air holes and seams simultaneously.

When we adopt the beads special for lost foam, air and condensate water in the beads can only be discharged from air plug because the bead diameter is small and there isn’t seam in the closing mould. And seam will make the parting surface produce burr.

② The pre-heating mould: before adding material, the pre-heating mould is to reduce the steam condensation in the bead foaming and molding process and shorten foaming and molding time.

 ③The material feeding: we should open the air outlet of fixed and movable moulds. We use the compressed air material feeding device to blow the pre-foamed beads into mould cavity by the mould’s material feeding mouth.

a. The material suction

The common material adding way. We use material gun and make use of compressed air to draw the beads into mould cavity. For simple mould cavity, this effect by this method is best. But for complex mould, the beads can’t fill up with the mould cavity.

b. Pressing and suction filling

In the material feeding process, the positive pressure is added on the beads to make beads fill up with the mould cavity and get certain compaction degree.

c. The negative pressure material suction filling

 In the material suction and material filling process, we add the negative pressure on the mould’s back face.

   In order to solve the bead’s material feeding problem of complex thin-wall model, we can also adopt the material feeding way of many material guns. For the above material feeding way, the material feeding way of many material guns can get best effect.  

④ The mould fixation and heating by steam

The steam enters into the mould fixation air chamber. By the air holes on the mould, it enters into mould cavity. The air and cold condensate water between beads are discharged from the movable mould cavity by air holes on the mould wall.

⑤ The movable mould by steam

The steam enters into the movable mould air chamber. By the air holes on the mould, it enters into the mould cavity and discharges the air & cold condensate water between beads from fixed mould cavity by the air holes on the mould wall.

⑥ The fixed and movable mould by steam     

The fixed and movable mould are steamed and keep a few seconds under the set pressure. The beads softens due to heating and re-expand. It fills up with bead’s full gaps of the mould cavity and stick to each other as a whole.

⑦ water cooling

We should close the steam and at the same time the cooling water is put into the fixed & movable mould air chamber for cooling & finalizing models & cooling mould to demould temperature, generally under 80℃.

⑧ vacuum cooling

We can let cooling water out and open the vacuum to cool the model further. It can reduce the moisture content in the model.

⑨ Opening mould and demould

We can start the mould on the molding machine and choose proper mould-taking way. We can use moisture superposition, mechanical plunger and vacuum sucking disc to take models out.