What Is Parting Line in SolidWorks?

The parting line is a critical concept in SolidWorks that plays a significant role in designing and manufacturing molded or casted parts. Understanding the parting line is essential for creating accurate and functional models. In this article, we will explore what the parting line is, why it is important, and how to define it in SolidWorks.

What is the Parting Line?

The parting line, also known as the mold split line or simply split line, refers to the imaginary boundary that separates the two halves of a mold used for injection molding or casting processes. It represents the point where the two mold halves meet and separate to allow for the removal of the finished part from the mold.

When designing parts that require molds, it is crucial to consider the parting line early in the design process. The location and orientation of the parting line can significantly affect factors such as manufacturability, cost, quality, and aesthetics.

Why is Parting Line Important?

The parting line has several practical implications in both design and manufacturing:

  • Separation of Mold Halves: The primary function of the parting line is to separate the mold into two halves so that finished parts can be removed easily without damaging them or compromising their geometry.
  • Avoid Undercuts: The location of the parting line determines whether undercuts are present on a design. Undercuts are features that prevent direct ejection from a mold due to their shape or position.

    By considering undercuts during design, you can avoid complex tooling or additional operations required to release parts with undercuts.

  • Mold Design: The placement of the parting line affects the mold design. It determines the number of mold pieces, complexity of slides or lifters, and the type of mold required (e.g., two-plate, three-plate, or side-action).
  • Quality Control: The parting line affects the overall appearance and quality of the finished part. A poorly located parting line can result in visible flash (excess material) or mismatched surfaces on the final product.

Defining Parting Line in SolidWorks

In SolidWorks, defining the parting line is a crucial step in preparing your model for injection molding or casting. Here’s how you can define the parting line:

1. Analyze Your Design:

Start by analyzing your design to identify potential parting lines. Look for natural breaks or features that would make sense as separation points between mold halves.

2. Create Sketches:

In SolidWorks, create 2D sketches on appropriate planes to represent the parting line. These sketches should follow a closed-loop profile that represents the desired separation between mold halves.

3. Split Part:

Select “Insert” from the top menu and choose “Features” > “Split.” Select your sketch as the splitting tool and choose which side of the sketch is to be kept as a separate body.

4. Apply Draft Angles:

To ensure easy ejection from molds, apply draft angles to features perpendicular to the parting line direction.

5. Check Interference Analysis:

Use SolidWorks’ interference analysis tools to verify that the parting line and split features do not interfere with other components or surfaces.

By following these steps, you can define the parting line accurately in SolidWorks and ensure a successful manufacturing process.

Conclusion

The parting line is a critical element to consider when designing parts for injection molding or casting. By understanding its significance and properly defining it in SolidWorks, you can optimize your design for manufacturability, minimize undercuts, and achieve high-quality finished parts. Remember to carefully analyze your design, create sketches, split the part, apply draft angles, and perform interference analysis to successfully define the parting line in your SolidWorks model.