Welcome Guest!

Select Level

Lesson 10: Gate Blush and Halo

Polymer material flows from a molding machine through a runner system and gates into a mold cavity. If the gates are too small for the project, a molding defect can develop near the gate on the final part. This lesson will focus on the molding defect called gate blush, which sometimes appears as a dull spot or a halo on the molded part.

Topics in this lesson include: the three primary reasons for gate blush; how gate types, sizes and locations determine blush and halo effects; if cavity filling velocity affects flow-induced shear stress and flow-induced residual shear stress; and why to compare residual shear stresses during the filling and packing phases.

You are not signed up for this course. Subscribe here!

Gate Blush and Halo

Learn about the causes of common molding defects and how to prevent them. Continue to build your own Circle of Knowledge lesson by lesson. 

Goals of Molding Defects (Level 2): 

  • Learn about the various molding defects that can occur during the injection molding process
  • Gain an understanding of how part design, mold design, and process impact molding defects
  • Analyze real-life molded parts and learn the cause and effect behaviors of design and process

Section Description: 

Molding defects in injection-molded parts range from minor surface defects to major structural issues that significantly impact overall part quality. This section shows you common molding defects, how and why the occur, and ways to minimize or prevent them.

NEW FOR LEVEL 2 MOLDING DEFECTS LESSONS: Each lesson has multiple samples of the molding defect using interactive 3D parts. The examples allow the user to manipulate the simulated part to gain a clear and concise understanding of how each molding defect would appear on a real-life injection molded part.

Video explanations, interactive 3D molding defect examples, simulations, and cause and effect analyses are covered in this section.

Recommended For: Mid-Level Personnel, All Personnel

Length: Lessons are approximately 15-20 minutes long each

The Kruse Training platform delivers knowledge and expertise developed over two decades in the plastic injection molding industry. Now companies and individuals can access a state-of-the-art online training program, suited for all levels of knowledge.