Plastic Injection Molding Process

Injection Molding Important Elements


Injection molding refers to the process in which plastic pellets are fed into the hopper of an injection machines, where they are melted under heat to maintain a flowing state. Then, under certain pressure, the molten plastic will be injected into a closed mold though the injection nozzle and the runner system of the mold. After cooling and shaping, the molten plastic will be solidified into the desired plastic part.

injection molding barrel

The function of injection molding barrel

  • Uniform Plasticizing
  • Less Pressure Loss
  • Faster Cycles
  • Uniform Stock Temperature

Important Process Variables

  • Melt Temperature
  • Mold Temperature
  • Temperature Profiles
  • Residence Time
  • Injection Speed
  • Injection Pressure
  • Pack Pressure
  • Clamp Tonnage

Melt Temperature


  • Drying temperature and time are an important key factor for good products in our production

Mold Temperature

  • Mold Temperature is critical in glossary and residue strain of part
  • Uniform  mold temperature reduces the effects of warpage.
  • Commonly controlled by water cooling channels.

Injection Speed

Injection speed
Injection Speed affects the viscosity of the molten material.

Injection molding pressure

injection molding pressure
Pressure Applied by Injection Ram to Force the Plastic From the Barrel to the Mold.


material regrinding machines

  • Use Only Clean Non-degraded
  • Uncontaminated Resin for Regrind
  • Keep It As New Material
  • Normally 20% of Regrind can be Used
  • Screen Sizes should be 7 to 9 mm



Ten Do for Molding Engineering Resins

  • Know Your Material
  • Dry Properly
  • Use Recommended Processing Conditions
  • Use Properly Sized Equipment
  • Use Properly Designed Tooling
  • Use Adequate Runners
  • Use Proper Venting
  • Use Nozzles with Proper Heat
  • Use Proper Screw Design
  • Schedule Annual or Bi-Annual Equipment Maintenance

Our injection shop

Our injection molding factory is equipped with 20 sets of high precision injection machines, ranging from 50 tons to 650 tons, They are mostly imported from Taiwan and Japan, our injection shop run 24 hours a day, 7 days a week, and provide full time production services.

We are experienced with various plastic injection molding products for many industrial, including automotive, medical, lighting, sports equipment, home appliances, and agriculture. We are an accredited and ISO9001-2008 company since 2004, We also have 5 IPQC people constantly watch our production and check the part quality, This ensures our production maintains the highest level of quality.

injection molding factory in China

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