ADDITIVE MANUFACTURING is the magazine devoted to industrial applications of 3D printing and digital layering technology. We cover the promise and the challenges of this technology for making functional tooling and end-use production parts.
Issue link: https://am.epubxp.com/i/667993
MAY 2016 Additive Manufacturing 16 TAKING SHAPE R&D; Project Demonstrates Metal AM for Mold Tooling Makers By Stephanie Hendrixson The clear model on the right of the metal test core shows the spiraling pattern of the conformal cooling channels, while the cross-section model (left) illustrates the clover-shaped passageways and is color-coded to show how the coolant fows in two diferent directions. Companies making injection molds and other plastics mold tooling in the Dayton, Ohio, area will soon have a nearby resource for learning what additive manufacturing can bring to this toolmaking. As part of a project funded by a grant from the Ohio De- velopment Services Agency, Dayton 3D-printing frm Bastech has installed a ProX 200 Direct Metal Printing machine from 3D Systems, and is devel- oping an injection mold tooling case study using this machine. The project will help convey the benefts and best practices of growing mold tooling through additive manufacturing to mold shops throughout the area. Bastech itself is no stranger to toolmaking. The 3D-printing service bureau and equipment reseller has a history of producing not just investment casting patterns but also short-run rapid tooling, using both traditional machining and nontradition- al processes. In addition to its additive lab, Bastech has a full machine shop where it cuts metal tools from stock and fnishes those that have been forged of-site. Now, the project aimed at creating production injection mold tooling on its new metal additive manufacturing machine will enable the company to produce complex mold cores and cavities through AM, while serving as an example for fellow toolmakers. The case study will focus on additively manufacturing injection mold cores and cavities for a promotional product that can be used as a giveaway . In the frst phase of the project, the company built the core for a cylindrical mold (center of the photo) from stainless steel 316 in the ProX machine. Bastech wanted to choose a design where additive manufacturing could provide added value; for the mold core, this value comes in the form of complex conformal cooling channels. The core that was developed includes two sets of channels spiraling inside its cylindrical body—one carrying coolant from top to bottom, and the other from bot- tom to top. This pattern helps to ensure more even cooling distribution throughout the entire length of the core; if coolant fowed in only one direction, it would heat too much by the time it reached the other end. The channels were designed with a clover-shaped geometry to increase the surface area and add turbulence to the fuid, further improving the cooling of the mold. Because the goal of the project is to educate, not just produce, Bastech has leveraged its polymer 3D-printing capability to create visual aids that show of the design features of this test part. In the photo to the left a prototype of the metal core is fanked by a full-sized clear plastic model that shows the paths of the conformal cooling channels. On the other side, a color-coded cross-section model made on the company's 3D Systems ColorJet 3D printer shows the clover shape and layout of the channels. The blue coloring represents the cool incoming coolant, while the red indi- cates hot, outgoing fuid. As a result of this project the company hopes to demonstrate to other moldmakers that direct metal additive manufacturing is a viable process for building mold tooling, whether they are considering it as an outsourced option or an in-house capability. In addition to telling customers about its new capability during regular business, Bastech is displaying its test parts and talking about the project at local and national trade shows and conferences throughout 2016.