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Original Publication Date: 1999-Oct-01
Included in the Prior Art Database: 2003-Jun-19

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This disclosure describes a method to mass produce a carbon fiber reinforced polymer composite Actuator E-block using coextrusion. The advantages are increased servo bandwidth, reduced actuator rotational inertia and decreased gain of E-block structural resonances by using carbon fiber composites having high specific stiffness, low density and greater ramping ratio. Any number of polymers, such as poly-ether-ether-ketone (PEEK) as an example, or epoxies can be used as the matrix surrounding the reinforcing fibers of carbon. The density and specific stiffness of 70% carbon filled PEEK are respectively 40% less and 344% greater than 6061 aluminum the current comb extrusion material. Measurements have shown the damping ratio to be two to ten times better than 6061 aluminum. A monolithic E-block, or comb, method of construction is proposed by one of two techniques. The first method is coextruding continuous or chopped carbon fiber along with the polymer or epoxy to form the near net shape of individual flat arms, spacers and coil yoke. Those parts are then stacked into an E-block mold and either autoclaved (heated under pressure) to fuse the parts together or additional molten polymer or epoxy is injected into the gaps between the parts to bond them together. The second method is to build up a complete E-block by a series of coextrusion steps. This process starts by first extruding the bottom arm, continuing up to the comb body (bearing bore), placing a removable tooling spacer to fill the gap between the first and the second arm, then extruding the second arm on top of the tooling spacer, and continuing to build up the comb arm by arm along the z-axis direction using a series of spacers. The tooling spacers are removed once the E-block is complete. Multiple nozzles configured in a two-dimensional array can mass produce the E-blocks in large batches. 1