Automated Tow/Tape Placement System

This NASA invention enables several benefits that mitigate limitations associated with conventional ATP systems, including the following: (1) avoids obtuse head rotation or cross-tool translation when laying adjunct tape plies, (2) simultaneously places tape on both sides of a part via two robots, (3) eliminates external anchoring frame requirements, and (4) translates parts during build while also translating the applicator head. The ability to perform simultaneous layup on opposite sides of the component, as well as reduction of head rotation reversal during bidirectional tape layup, offers increased layup speed. The invention offers increased placement accuracy as a result of reduced movement between tape layup operations and the eliminated need for an anchoring frame (facilitated by simultaneous pressure extrusion of prepreg by the two robots). NASA’s automated tow/tape placement system has two key unique features: the use of two opposed ATP cars to enable a tool-less process, and an on-the-fly reversal tape/tow laydown tooling head. The system uses two opposing (i.e., underside-to-underside) ATP cars, and can build parts vertically, horizontally, or at any other angle, depending on the workspace available. The ATP die wheels can be reversed or turned to draw the composite back and forth at different angles to create a layer-by-layer composite structure. Both cars can dispense TPC tape – thus, either car can function as an opposing tool surface while the other performs prepreg lay-up. For structures that do not vary in thickness, both cars can lay tape at the same time – doubling layup speed. Current ATP robots must rotate the large tooling head, or traverse panels without layering tape to achieve bidirectional layup, where each additional movement introduces alignment error. To increase layup rate while simultaneously minimizing misalignment, NASA’s system incorporates an on-the-fly reversal tape/tow laydown tooling head to enable efficient bidirectional layup. In recent years, industry adoption of thermoplastic composites (TPCs) in lieu of thermosets and metallic structures has increased for the fabrication of air and launch vehicle components. Manufacturing of TPCs, performed via automated tape laying (ATL) and automated fiber placement (AFP), uses machines that place prepreg tow or tapes on molds in a unidirectional manner, which then undergo cure cycles, autoclaving, and other steps that require special tooling. The process is time, material, and energy intensive, requires large facilities to house equipment, and limits the size, mechanical properties and shapes of the parts manufactured. To address these limitations, NASA’s Langley Research Center has developed a simplified, tool-less automated tow/tape placement (ATP) system. The invention uses two opposed ATP cars working in tandem to achieve tool-less operation, bidirectional lay-up, and expansion of the design space and size of TPC components that can be manufactured using ATP systems.