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Disadvantages of plastics formed by injection molding and solutions to these disadvantages

In some cases, there are defects and problems in the injection molded plastic parts, each of which can be a defect or defect in the forming process, forming conditions, raw materials, mold, or a number of these.
By modifying each of them, we can have a flawless and functional piece. Some of the problems we encounter after injection are as follows:

  • Plastic part distortion
  • Excessive brittleness and less than the sample failure stress
  • The full mold is not filled
  • Implant injection
  • Leakage of material from the nozzle
  • Sticking the piece to the mold and not easily detaching from the mold
  • The effect of the splitter on the surface of the sample remains
  • Dimensional instability
  • Deformation of the piece when leaving the mold
  • Drill on the piece
  • There are black spots on the piece
  • Bubble on the piece
  • Layering
  • Silver streaks
  • Blistering on the surface of the piece
  • Whitening of the piece due to stress
  • Change the color of the piece
  • Creating a jetting phenomenon or filling the mold from the end
  • Low gloss or change in sample gloss
  • Creating a cloudy surface and poor welding line


The above disadvantages of each alone or together can be found in the injection piece. For polyethylene, polypropylene, PVC, polyamide, polycarbonate, polystyrene, etc. parts of the process may be different, but these are common cases that we often encounter in the injection process and may be for Each injection piece is created. These disadvantages and problems can be solved by modifying and changing the effective parameters in the injection such as injection speed, injection temperature, pressure and… materials and plastic injection mold. For each of the above disadvantages, there are solutions that have priority given their nature. In the continuation of this series of articles, we want to examine the causes of each of these problems and examine its solutions. Stay with us …