CYCLE TIME EFFICIENCY

When it comes to injection molding, the goal is to try to cool the plastic part while in the mold as quickly as possible.  This obviously is tied to cycle time and can then be used to reduce time and then associated cost. There is however, a series of compromises that are made during this reduction. If the product is designed to have thick walls or molded of delicate materials that are difficult to process, then the product may suffer with material degradation, dimensional problems, or even part breakage. A delicate balance between quality, cost, and speed needs to be made in order for the product to be successful. Since most plastic parts are molded in black, a large number of these parts have burns and material problems that do not show up during inspection. Special care must be taken to review parts for signs of not only surface defects but also problems within the wall such as voids on stiff materials, sinks on weaker materials, and burns in difficult areas or at end of fill. Material degradation can have major negative affects on the material especially if the part is load bearing.  Other problems concerning moisture within the material such as  with Nylon or Polycarbonate can also have huge affects to material properties.  So just because a mold can run at a faster cycle does not necessarily mean that it should be run at that speed considering all the other requirements.