By Kurt NordlundPresidentSeco Tools, LLCwww.secotools.com
Today, a great deal of excitement, speculation and, in some cases, concern exists about the use of 3D printing technology for part manufacturing. Consumers are especially excited about the technology because it has the potential to let them replace broken household parts—moderately accurate plastic components—by printing new ones. The scope of such component processing capability, however, is quickly broadening. In its first stages of development, 3D printing had a few limitations for major manufacturing applications in regards to strength, speed, materials and accuracy. Typically, parts made through 3D printing carried very low loads, so they weren’t structural components, per se. However, as the technology improves, 3D printing is capable of generating parts with mechanical properties reasonably close to those of traditional materials, making it possible to produce load-carrying components. Major manufacturers, such as General Electric, Boeing and Ford, continue to evaluate, test and push the limits of 3D printing technology in efforts to produce parts with structural integrity—and they have done so with amazing levels of success. Additionally, more manufacturers are using 3D technology to bring innovative part designs to life that would otherwise prove impossible to produce using traditional machining methods. Instead of competing one-on-one with traditional methods, 3D technology stretches the boundaries of manufacturing capabilities in terms of part complexity. Perhaps the best current industrial applications of 3D printing still involve the production of one-offs or prototypes. In fact, Seco used 3D printing more than 10 years ago for prototyping in tool development. The machine ran overnight and provided a plastic part the next morning.In some instances, 3D printing helped speed the development process. Instead of performing trial and error with the material intended to be used in the final tool, a prototype produced through 3D printing could help verify the tool’s configuration and manufacturability. The process was a valuable tool for Seco, but we have since largely replaced it with sophisticated visualization capability from today’s 3D CAD systems. The use of 3D printing equipment continues to grow, but the technology’s use in the cutting tool manufacturing business, for instance, remains extremely minimal—mainly because of the processes used to produce cutting tools. With cutting tool inserts, for example, most tool materials are composites of metal powders including hard constituents and binder phases. Those elements are discreet, not intermixed into one blend. The powders are pressed to the shape of an insert and sintered in a furnace.Granted, there is some work going on in 3D printing with composites and mixed materials, but to be able to handle the complexity of cutting tool manufacturing with 3D printing appears to be a little tricky at this time. In the production of molds, the speed of 3D printing hinders its use. 3D printing is a shortcut that will provide a fast prototype part without having to make a mold and inject it with plastic. But molds and injection molding systems are required when hundreds and thousands of parts are needed. 3D printing is going to be a very important technology for shortening lead times in developing and evaluating products, but it is going to take time for the process to evolve as a viable alternative for producing high-volume items. Accuracy, another issue of current 3D printing processes, improves continually. When Seco was working with 3D printing, the process was surprisingly accurate. But as is always the case in manufacturing, the more accuracy that is desired, the more cost involved, both in terms of equipment expense and time. To determine the usefulness of 3D printing for a particular application, manufacturers should first develop a grid or matrix to track relating factors such as the quantity and accuracy of parts required, their function, material and the time and money available to produce them. More long-term projections about future advancements in 3D printing technology should be included as well because the development of the process is so dynamic.3D printing provides flexibility and speed for certain applications, but many manufacturers continue to be skeptical about it replacing all existing technology. They do agree, however, that the technology should be closely watched in terms of any new future manufacturing process value. ME
This article was first published in the February 2014 edition of Manufacturing Engineering magazine. Click here for PDF.