Half your printing time and reduce warpage as a bonus

Topology optimization is often associated with highly specialized light-weight designs for aerospace. However, as additive manufacturing is expanding into other industrial sectors, topology optimization is following suit. In this post we demonstrate how topology optimization applies to "Design for AM" in a more general sense and can be used to cut print times dramatically by removing excessive material.

Additively manufactured inserts for injection moulding already has a well established business model. Through the design of intricate conformal cooling channels, the increased performance of the mould justifies the increased cost of printing the insert. The cost of the insert is tightly coupled to the manufacturing time and necessary corrective actions to counteract warpage.

The design process usually follows the traditional design steps:

  • Start with a block!
  • Design the cavities used for molding.
  • Design the cooling channels.

This is all fine from a traditional manufacturing view point. From an additive manufacturing view point, however, a crucial step is missing:

  • Remove excessive material!

This step is skipped either because of tradition (This is not what we normally do! Only a solid block is strong enough!) or because of inadequate software tools (This is difficult and will take a long time!). It is hard to change tradition, but software tools is what we do, so let's start by making them smarter.

In the pictures above you see a design for a quarter of a moulding insert with conformal cooling channels. A is the current design, which is being manufactured by AM. In B you see the same fundamental design, but with excessive material removed. In total 50 % of the material is removed without jeopardizing mechanical and thermal performance of the mould insert. The reduction of material immediately decreases manufacturing price and reduces thermal warpage challenges significantly.

So how do we arrive at the light-weight design? High resolution topology optimization to the rescue: After specifying fixed and loaded surfaces, the optimization algorithm removes material automatically. The high resolution ensures smooth and finished designs ready for manufacturing without further interpretation. The channels and moulding cavities are still defined in CAD and can be used for CAM planning as usual - only the interior volume is modified. The workflow is described in more detail in this old blog post.

High resolution topology optimization has the potential to improve your AM business model significantly and probably make AM attractive for parts you have previously dismissed.

Written by Klaus Loft Højbjerre ·

Tagged with Case story, 3D print, Topology optimization and Injection molding.