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Lesson 1: Short Shots (Processing)

Generally, molding defects are either part design, mold design, or process related. This lesson focuses on processing-related short shots, a condition where portions of a part remain unfilled. The next lesson will cover part and mold design-related short shots. Injection molding is a complex scientific manufacturing process. By following a methodical set-up process, molders aim to minimize or eliminate common molding defects that affect part quality.

Topics in this lesson include:  the potential reasons for short shots; how to run various sensitivity analyses to evaluate process parameters affecting short shot conditions; and how melt and mold temperature, cavity fill time, injection velocity profiling, switch-over set-point from filling to packing, and the initial packing pressure affect short shots.


Short Shots Processing

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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 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.

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