How to Adjust Low Pressure Mold Clamping?

If there is a loud sound of mold opening and clamping in the injection molding workshop, then it must be the molding technical management personnel have not adjusted it properly.

The mold clamping action process is divided into five stages, roughly as follows:

Slow start  fast mold clamping  slow buffering  low pressure mold protection  high pressure mold clamping.

The following is an example of a Kaiming machine manufactured in 2015 and a set of two-plate molds without springs and inclined guide posts. The mold opening position is 450mm.

248T Kaiming Machine Clamping Parameter Setting

248T Kaiming Machine Clamping Parameter Setting

1. Slow start

Walk 10mm-50mm from the end position of mold opening, that is, from 450mm to 400mm. The slow start is for the smooth start of the machine without shaking and damaging the machine. If there are injection molded embedded inserts, prevent the inserts from falling out or shifting. In order not to waste cycles (too slow is also unscientific) the pressure and speed settings should be set according to the machine conditions.

Principle: smooth, quick start.

2. Fast mold clamping

From 400mm to 80mm. This step is to ensure that the machine is stable, does not vibrate, does not make abnormal noises, and the embedded inserts are not misaligned and do not fall out. The sooner the better.

3. Slow buffering

From 80mm to 20mm. After fast mold clamping, it is necessary to have a buffer stroke to prevent the mold from being damaged due to inertial impact. This stroke should not be set too long for cycle benefit, generally around 40mm-60mm. If the mold has slanted guide pillars, row positions, etc., it should be set by lengthening 10mm-30mm according to the length of the slanted guide pillars.

The pressure setting standard of the above 3 points:

Being able to push the mold to go at the set speed will be fine. The lower the pressure, the better. Do not set the pressure too high, generally between 20-80.

Two templates

Two templates without inclined guide posts, row positions, and springs

4. Low pressure mold guard

From 20mm to 1mm. This step is the key point in the entire low pressure mold clamping!

  • The pressure must be set from 0, as long as it can lock and lift the mold. Andthe maximum should not exceed 20.
  • The speed is set from 5 with the maximum not exceeding For cycle efficiency, the speed is generally between 20 and 30.
  • The low pressure protection time should be set according to the actual required time, generally less than 3 seconds.

Low pressure test:

Fold a A4 paper once, put it into the parting contact surface of the mold. It’s better if the mold clamping doesn’t alarm. 

Carry out the mold clamping test with PP nozzle. If there are traces, no being flattened and no alarm, then it means that the low pressure mold clamping has been successfully debugged.

These parameters of low pressure mold clamping must be fixed and cannot be increased at will!

* If the mold is not good, and the mold workers are required to improve the smooth mold clamping of the mold, and there must be no abnormal friction resistance.

* If the injection molding machine is not working, the equipment maintenance personnel are required to maintain the machine, making it output the pressure and speed according to the standard of the injection molding machine.

Injection molding machine technicians must abide by the high pressure lines of this industry! Do not increase the pressure and increase the speed for low-pressure mold clamping! Tuning personnel need to stick to the right injection molding concept, and eradicate these moth thoughts that harm the factory’s efficient production for the convenience of their own work.

5. High pressure mold clamping

From 1mm to stop.

The high-pressure mold clamping position must be set by the position data that the parting surfaces of the front and rear molds are closely attached to. If it is a high-end precision machine, the positionis generally below 0.5mm. While for ordinary machines, it is generally below 2mm. For worn-out machines, it should be set according to the page data that the actual mold parting surface is closely attached to.

The high pressure should not exceed 90% of the maximum pressure, and the speed should be below 40. Note that the mold should be clamped tightly. When the high pressure is activated during the mold clamping, the system pressure gauge needle should be at the 9-11 o’clock position.

The high pressure protection time is generally not more than 2 seconds as well.

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