Welcome Guest!

Select Level

Lesson 3: Entrapments

The injection molding process is a complex 3-dimensional polymer flow and transient heat exchange manufacturing process. Part design, mold design, and the molding process are all intrinsic to a successful outcome. This lesson focuses on gas and air entrapments, a common molding defect that can create numerous issues including burn marks, short shots, and blemishes in molded parts. Optimizing part geometry and mold design is essential for avoiding entrapments.

Topics in this lesson include: the causes and possible solutions for entrapment during the filling process; how race tracking and hesitations can cause entrapments; how internal venting may be a solution for entrapment conditions; and how wall thickness variations can cause entrapments.

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

Entrapments

Learn about the causes of common molding defects and how to prevent them. Continue to build your 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 impacting overall quality. This section explains common molding defects, how and why they occur, and ways to minimize or prevent them.

Each lesson includes multiple samples of molding defects using interactive 3D parts. The examples allow the user to manipulate the part to gain a clear and concise understanding of how each molding defect would appear on a real-life injection-molded part.

This section covers video explanations, interactive 3D molding defect examples, simulations, and cause-and-effect analyses.

Recommendation: Expert-Level Operators, Technicians, & Designers

Length: Lessons are approximately 15-20 minutes long each

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