In the injection molding business, it is essential to produce high quality parts without molding defects. In part two of the lesson we will further evaluate design and process-related sink marks and voids.
Topics in this lesson include: various part design related challenges that impact the fill-to-shrinkage behavior of a molded part; the importance of evaluating and eliminating sink marks and voids prior to finalizing a part design; that injection pressure requirements may be dictated by sprue, runner, and gate sizes, but not necessarily by the wall thicknesses inside the molded part; and the way that polymer material cools inside the mold cavity may result in shrinkage and possible sink marks and void development.