HOW TO SPLIT A 3 PART BLOW MOLDING IN SOLIDWORKS

Описание: In Blow molding, a 3-part die (also called a three-plate or multi-slide die) is used when a component has undercuts, side features, or complex geometry that cannot be released with a simple two-part mold. SolidWorks provides powerful tools such as Parting Line, Shut-off Surfaces, Tooling Split, and Save Bodies to create these die components accurately.Splitting a three-part die casting in SolidWorks is an important process in mold and die design, especially for components that contain side undercuts, complex shapes, or features that cannot be released using a simple two-part die. A three-part die typically consists of a core, a cavity, and an additional side core or slide. SolidWorks provides dedicated Mold Tools that make this process systematic and accurate when followed correctly. Before starting the die-splitting process, it is essential to prepare the die-cast component to ensure manufacturability and avoid errors during tooling operations.

The first step in splitting a three-part die casting is preparing the model. The part must be a fully defined solid body with no gaps, missing faces, or surface errors. If the model has been imported from another CAD system, Import Diagnostics should be used to heal faulty faces and edges. Draft angles are critical in die casting, as they allow easy ejection of the part from the mold. Draft Analysis in SolidWorks is used to evaluate whether the part has sufficient draft in the intended pull direction. External surfaces generally require one to three degrees of draft, while internal surfaces may require two to five degrees. If insufficient draft is detected, the Draft feature is applied to correct the geometry. This preparation stage ensures that the mold can open smoothly without damaging the casting.

Once the part is ready, the next step is identifying the die opening directions. In a three-part die, there are at least two pull directions: the main opening direction for the core and cavity, and a secondary opening direction for the side core. The main pull direction is usually aligned with the longest axis of the part, while the side pull direction corresponds to features such as side holes, slots, or undercuts. Reference planes or axes are created to define these directions clearly. These reference directions guide SolidWorks in detecting parting lines and undercut regions accurately.

After defining the tooling directions, parting lines are created using the Mold Tools Parting Line feature. The parting line represents the boundary where the core and cavity separate. SolidWorks automatically detects edges where the draft changes direction relative to the pull direction. The designer must ensure that the detected parting line forms a continuous closed loop around the part. If the loop is broken, it indicates missing draft or problematic geometry that must be corrected. A clean and continuous parting line is essential for creating accurate parting surfaces later in the process.

Following the creation of parting lines, shut-off surfaces are generated. Shut-off surfaces are used to close holes, windows, and open pockets that would otherwise cause molten metal to flow into unwanted areas during die casting. In SolidWorks, the Shut-off Surface tool is used to seal these openings by creating surface patches across them. These surfaces can be created with contact or tangent conditions depending on the shape of the opening. Proper shut-off surfaces ensure that the tooling split produces solid mold halves rather than incomplete or hollow bodies.

Once the parting line and shut-off surfaces are complete, parting surfaces are created. Parting surfaces extend outward from the parting line and form the separation boundary between the core and cavity. Using the Parting Surface tool, the designer selects the parting line and specifies an extension distance sufficient to fully divide the mold blocks. These surfaces must extend beyond the geometry of the part to allow proper mold separation. The quality of the parting surface directly affects the accuracy and strength of the mold.

With parting surfaces in place, the Tooling Split feature is used to separate the mold into core and cavity bodies. During this operation, the user selects the tooling direction, parting surfaces, and shut-off surfaces. SolidWorks then automatically creates two solid bodies representing the core and cavity halves of the die. At this stage, the mold is still a two-part die, and undercuts caused by side features remain unresolved.