Thermwood Corp. (Dale, IN), a U.S.-based manufacturer of CNC routers and customer of American Kuhne (Ashaway, RI), a provider of engineered solutions for plastics, rubber and silicone extrusion, announced that its developmental system for Large Scale 3D Additive Manufacturing (LSAM) performed well during initial testing through its entire operating range. The testing follows a July announcement of its LSAM program.
Kevin Slusarz, American Kuhne Vice President of Process Technology assisted in the start-up effort. “It is my pleasure to support Thermwood beyond the design phase. This was a good opportunity to combine our polymer processing know-how with Thermwood’s CNC technology expertise to advise optimizations to melt piping and tooling design for this unique application,” he said.
Thermwood’s development system is supplied by a 1 ¾ -in. American Kuhne extruder custom engineered for this application. Thermwood Chairman & CEO Ken Susnjara, commented, “We are quite pleased without selection of American Kuhne as our development partner in this effort, not only for the quality of the equipment, but also for the service and support.”
Thermwood expects to fit this initial test machine, which can print parts up to 10’x 10’ x 5’ thick, with a 5-axis ‘subtractive’ gantry trim system in the next few months. This will enable the system to perform both the ‘additive’ and ‘subtractive’ functions on the same machine. Called “near net shape,” this approach uses a high volume thermoplastic printer to quickly create a part that is nearly, but not exactly, the final net shape. The “subtractive” function then machines the part to the exact final net shape.
Testing included validation of an all new “MeltShape Technology” for enhanced control of layer shape and improved bonding between layers—a new and promising technique in the advancement of LSAM. This new patent-pending approach uses one or more shaping wheels to shape, form and compress the hot plastic melt as it is being extruded, insuring that each new layer is the proper shape and thickness and that it bonds firmly to previously applied material, said the companies’ release.
Thermwood plans to continue this development effort with the goal of offering these machines in a variety of large sizes for commercial applications, specifically targeting aerospace patterns and molds. Management cannot yet determine when the technology might be sufficiently refined for commercial rather than purely research and development applications. Thermwood plans to work with material vendors, R&D organizations and potential users in the ongoing development effort.
The Graham Group (York, PA) acquired majority interest in American Kuhne in 2012, followed by Graham Engineering Corp.’s acquisition of Welex (York, PA) in June 2013. Together, Graham Engineering, American Kuhne, and Welex create a convergence of leading technologies, people, and capabilities in extrusion, said American Kuhne. Welex provides high-performance sheet extrusion solutions, with equipment installed in more than 3,000 customer locations in 69 countries. Welex innovations include co-extrusion and multi-layer methods, as well as dozens of barrier lines installed globally.