Fill Injection Process in Plastic Injection Molding Machines

As we know, some machines use ball screws to facilitate movement and require maintenance or ball screw repair, and that also applies to plastic injection machines. After making sure the Mold is pressed with high pressure. Then the Injection Unit consists of Nozzle, Barrel, and Screw and so on. Move closer to the Mold until the Nozzle touches the Mold, also with high pressure (Up to 100 kg / cm²). The picture above shows the Nozzle already in contact with the Mold. The part of the mold that comes into direct contact with the Nozzle is called the “Sprue Bush”. Then the machine performs the injection process, which injects liquid plastic into the Mold. In this process involves several parameters that we can set in such a way as to follow the level of difficulty of the product that we will make our website, namely:

1. Fill Pressure.
Current output machines have variations in the level of filling pressure more than 2 levels and also followed by variations in the position of each filling pressure. So that we can determine in which position, when the liquid plastic formed the product, requires the amount of Filling Pressure “so much” its value, and in other positions with the same product still requires the amount of Filling Pressure “so much”, and so on. The magnitude of the Filling Pressure that we set simply higher than the actual Filling Pressure, or about 30%. This pressure is to deal with pressure fluctuations when the Filling Process takes place by taking into account the “Pressure Gauge” (Hydraulic pressure gauge) available on the injection unit or shown on the monitor screen for those who are already digital. This occurs due to obstacles when water flows or enters spaces in the Mold, and the Filling Pressure must not be overcome by these obstacles. There are two levels of parameters for filling pressure:

1. PF1 with a magnitude of 90 kg / cm² in position (PFS1) 200 mm. 2. PF2 with a magnitude of 120 kg / cm² in position (PFS2) 150 mm. 3. PF3 with a quantity of 100 kg / cm² in position (PFS3) 70 mm.

2. Fill Velocity.
There are variations in the level of speed that we can adjust and are needed to avoid the existence of undesirable product conditions. Even the speed levels can be adjusted according to the position of the plastic flow when forming the product. On the current machine, there are at least 5 levels of speed with 5 positions, or even more. For example:

1. PV1 with a magnitude of 40% in the “Shot Size” position of 200 mm.
2. PV2 with a magnitude of 60% at position (PVS1) 170 mm.
3. PV3 with a magnitude of 70% at position (PVS2) 150 mm.
4. PV4 with a magnitude of 50% at position (PVS3) 70 mm.
5. PV5 with a magnitude of 10% at position (PVS4) 20 mm.
6. Ends in the “V-P Change Over” position of 10 mm.

The product results from this process are still not perfect with little left and will be refined in the next process. Guarantees for the stability of the ongoing process are in this section, so it also determines the stability of the products made.

For previous machines that only provide 1 level of Filling Pressure and 1 or 2 levels of Filling Speed. This, of course, limits the ability of the machine when facing products with a certain level of difficulty, although the process of setting parameters is relatively easy and fast.

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