1. Phenomenon

A phenomenon in which silver streaks occur on the surface of a molded product.

  1. Cause
  • Poor air release (gas release)
  • Overly small gates, runners, and sprues
  • Insufficient degassing of the mold
  • Small slug well
  • A lot of water adsorbed on the resin
  • Insufficient injection pressure
  • Overly low mold temperature
  • High cylinder temperature
  • Fast injection speed
silver-streak

3. Measures

  • Create a gas vent
  • Increase the size of gate, runner, and sprue
  • Degas the mold
  • Enlarge the slug well
  • Fully pre-dry
  • Increase injection pressure
  • Increase mold temperature
  • Lower cylinder temperature
  • Slow the injection speed
  • Degas the runner end just below the sprue before entering the product.