Course: Injection molding defects – Weld lines

135.60 $ incl. tax


Whenever two melt fronts meet each other, we will get a weld line.
Depending on the application, weld lines can be troublesome or, in the worst case, lead to failure of the molded part.

So if we can not avoid weld lines on plastic parts, what are the methods to improve them?

Take a look to the course and learn all the tricks to optimize regions with weld lines.

SKU: EL11724 Category:

You will learn

  • What are the root causes of weld lines
  • Which parameter has the largest effect on weld line quality
  • How weld lines become invisible

This enables you to

  • Understand why a weld line is created
  • Modify the process to optimize weld lines
  • Minimize weld line effects


About the course: Injection molding defects - Weld lines

Action is required if a part produced with a good mold shows different gloss on the surface.

The type of surface defect must be identified in order to find a solution.
Adjustments of the parameters on the injection molding machines are needed.
In this course, the basics of surface defects are discussed. Along with that solutions are provided that will lead to good parts.


This course is for

Everyone who is curious about the topic.
This includes especially people working as:

  • Mold designer
  • Mold maker
  • CAE-team
  • Setter
  • Injection molder
  • Quality manager
  • Department leader
  • Simulation-Team
  • Project manager
  • Head of Design


Course details

For basic skill level

Around 40 min in duration

Video On-Demand lessons (1)

Spoken script

Expertise knowledge described step-by-step in text

Additional explanations on important technical terms

Full access on computer or mobile for one year

Certificate of completion when you finish the course

(1) Video streaming is part of the e-learning and shall be accessible in your browser.

Course Specialist

Prof. Dipl.-Ing. Peter Wippenbeck



For many years, Prof. Dipl.-Ing. Peter Wippenbeck has been connected to injection molding technology. He started with mechanical engineering and application technology. Even then, the aim was to achieve a perfect product with the best possible economic efficiency. Quite a few customers confronted him with problem cases and asked for solutions and optimized settings in production.


He took on teaching duties at Aalen University, in Germany, in the field of plastic technology in the 70’s to examine the experiences from industry and to pass on his knowledge to future generations of engineers. Soon, he got a managing position there. His work, with international cooperation, led to the establishment of the master’s degree program in Polymer Technology.


Initiated by the professional association of GKV (called TecPart), industrial training in the field of injection molding was intensified additionally to the engineering degree: Several thousand participants at seminars have already been trained by him and qualified in Aalen including a considerable number of foreign employees and trainers, especially from Thailand, India and Indonesia.


In organizational terms, these activities are located at the Steinbeis Innovationszentrum Kunststofftechnik (SIZK, a non-profit company of Steinbeis Innovation gGmbH), while problem-solving is the responsibility of the Steinbeis Transfer Zentrum Aalen Kunststofftechnik (STAK). In both institutes, the author has been engaged in knowledge transfer in the sense of quality improvement and efficiency in injection molding technology.