Injection Molding Parts

How to improve the efficiency of injection molding?

Injection Molding Parts

How to improve the efficiency of injection molding?

In recent years, the injection molding industry told the development.  Injection molding products are in all walks of life.  Mainly includes auto parts, electronic parts, hardware tools, electrical shells, etc.;  Aria is an injection molding manufacturer established for more than ten years from China, and the development rate of these years is much higher than the national average level.

Since 2010, Aria has focused on improving product quality and the production cycle for injection molding.

Plastic injection molding mainly includes the following steps:

Mold closing – Injection – Material storage – Cooling – Mold opening – Ejection.

Mold closing:

The process of mold from the open state to close. It is divided into several stages: fast mold, medium speed mold, low-pressure protection, high-pressure mold lock. This process is to close the mold smoothly, protect the mold, lock the mold.


The screw forward of the injection molding machine to squeeze the melt material into the mold. The injection stage is divided into injection and pressure preservation. The injection is to let them melt material in front of the screw head move forward according to the set parameters. The melted material gradually fills the mold under the push of the screw. As the melt material shrinks in the curing process at high temperatures, the melt material has to be filled again. This feeding stage is called pressure retention.

Material storage:

Also known as hot melting. After melting material is consumed in the injection stage, it is necessary to replenish the amount of material for the next cycle. Storage is the process of replenishing melting material and measuring it.  At the end of the pressure holding, the screw rotates to transport the material from behind to the front. During this period, due to the presence of shearing, heating, the material melts and accumulates at the head of the screw.  The screw does not retreat actively in the process of material storage, but with the gradual increase of the fabric in front of the screw and the establishment of pressure, the nozzle is blocked by the material in the mold, so the screw is pushed backward by the melting material to stop the measurement point.  As the screw recedes, the resistance, called backpressure, is also the pressure built up by the melt material in front of the screw.  The resistance of the screw back can be adjusted by the backpressure valve to make the front end of the melt material denser.


We need to pay attention to the cooling time, and the cooling time is the time of the plastic fixed-line. The cooling time starts from the end of the pressure holding, so the action of the material storage is completed during the cooling time. Also, even if the cooling time is set to 0, the next action will be carried out after the completion of the material storage. The cooling time is relatively large in the whole cycle.

Mold opening:

After cooling is completed, The next step is mold opening.  Action process including high-pressure mold opening, fast mold opening, medium speed mold opening, slow mold opening. The whole movement is smooth and smooth, close to the end of the die, no jitter, accurate position.  


After the die is opened, the product is left on the moving die of the die and needs a lot of force to remove. There is an ejector mechanism on the mold, which can push the product out.

If you want to shorten the overall injection cycle time to improve production efficiency, consider the following suggestions: 

  1. Give priority to shorten the time of opening the mold, the time of ejecting the finished product, and the time of taking out the finished product. Since it has the least impact on the quality, automatic taking out machines can be considered to reduce the time of uncertainty caused by manual work. 
  2. Don’t reduce the injection time in the injection molding process, Because the injection time and molding product quality have a great relationship. It is best to shorten the production time from the mold and product design changes, such as: Adjust the wall thickness of the design and modifying the product wall thickness evenly as possible.
  3. You can improve the cooling efficiency of the mold, such as whether the cooling waterway layout is appropriate, and consider adding more efficient refrigerant. Do not attempt to reduce the cooling time by lowering the mold temperature.
  • Ensure that the gate configuration is balanced, and try to avoid too long a preparation cycle.

  • Easy to sag parts should not be too far away from the gate or in the vicinity of the new gate.

  • Use hot runner system

  • Use larger injection molding machines.