Vortex control in slurry molding applications
A molding head is especially adapted for vacuum molding or forming of structures and, in particular, fibrous composite structures in an adjustable, controllable three dimensional orientation before, during and after molding. Such a molding head includes a mold plate with narrow slots in the mold surface thereof and wider channels in the back surface thereof, with such slots and channels intersecting one another. A control system of servomotors or other actuators permits movement and orientation of the mold head during forming, thereby creating the ability to vary the material properties based on gravity and particle or suspension grain, thickness and other now controllable properties.
1. A process for forming a molded part comprising:
providing a container for holding a material to be molded;
placing a mold head into said material wherein said mold head has at least one element selected from a vortex generator and a fence to expand or intensify vortex spin and said molding head has a mold screen thereon;
applying a reduced pressure to said molding head to draw said material through said mold head to form a vortex; and
moving said mold head with three degrees of freedom thereby selectively altering said vortex to drawn said material onto, or repel said material from, said mold screen.
2. The process for forming a molded part of claim 1 wherein said material is at least one of a pulp, slurry or suspension mixture.
3. The process for forming a molded part of claim 1 wherein said material comprises a fiber.
4. The process for forming a molded part of claim 3 wherein said fiber comprises at least one fiber selected from carbon fibers, para-aramid fiber, fiberglass, ceramic fibers, ceramic fiber precursors.
5. The process for forming a molded part of claim 1 in which said reduced pressure is provided by a pressure reduction device which includes at least one rotary union, such that vacuum pressure may be applied to said mold head while said mold head is in different positions within said container.
6. The process for forming a molded part of claim 5 wherein said pressure reduction device varies the vacuum pressure applied to said mold head during the molding operation.
7. The process for forming a molded part of claim 1 further comprising servos for moving said mold head.
8. The process for forming a molded part of claim 7 further comprising linear servos for moving said mold head within said container.
9. The process for forming a molded part of claim 1 wherein said material drawn through said mold head forms said vortex perpendicular to a portion of said mold head and said portion of said mold head is movable in a direction which is not perpendicular to said vortex.