Three companies collaborated on an automated process for producing large thermoplastic parts at high-speed deposition rates of up to 4,000 inches (100 meters) per minute.
The joint development comes from Electroimpact Inc., an automation supplier based in Mukilteo, Wash., Janicki Industries, a supplier of tools, prototypes and parts based in Sedro-Woolley, Wash., and Toray Advanced Composites.
For the project, Electroimpact enhanced its high-speed automated fiber placement (AFP) equipment for processing thermoplastic materials with a variable-spot-size laser heating system.
The system uses a large range of processing temperatures for robust control across individual tows. This accommodates severe contours while enabling thermoplastic composite parts to be repairable during AFP lay-up, which reduces waste as parts are manufactured.
Processing speeds of up to 4,000 IPM (100 m/min) have been achieved with light or heavy tack levels to guarantee part geometry, according to a news release.
"When these advancements are combined with increased AFP reliability, in-process real-time inspection and maintenance intervals, the resulting AFP 4.0 processing increases 4x-6x current productivity," Michael Assadi, chief engineer at Electroimpact, said in the release.
To maximize production efficiencies, the AFP layup is formed directly on to an out-of-autoclave heated lay-up tooling system engineered by Janicki Industries, which is then fully consolidated in-situ, achieving a complete thermal process cycle in less than one hour.
The tooling system is designed for scalability to accommodate parts that are too large for traditional heated press applications and achieves significantly faster cycle times than high temperature autoclaves.
The key to this technology is rapid heating and cooling rates with edge-to-edge uniformity throughout the process, according to Todd Chace, director of research and development at Janicki.
"Complete consolidation under vacuum bag only pressure is achieved by controlling the key stages of melt, flow, and crystallization with precise temperature control," Chace said.
For the process, Toray Cetex TC1225 low melt PAEK (LMPAEK) uni-directional tape was selected. The material best-in-class levels of impregnation, consistent quality parts, and it eliminates the need to wet-out fiber bundles during the consolidation cycle, which allows out of autoclave processing with near zero porosity.
Combined with a relatively low processing temperature when compared to other PAEK-based systems, Toray Cetex TC1225 LMPAEK enables a faster layup speed while achieving comparable mechanical properties, according to Steve Cease, vice president of technology and strategic marketing at Toray Advanced Composites.
"Individually, each of these technologies represents a step forward in thermoplastic composite processing. When combined, a major leap in large-scale, rapid part fabrication is achieved, underlining the importance of partnership across the value chain to advance the adoption of thermoplastic composites into industry," Cease said.