Method and apparatus for forming fiber reinforced plastic preforms from a wet slurry

Claim 1

A method of forming a structure from a fiber reinforced plastic preform which comprises: (a) placing a screen shaped to a desired preform configuration near the bottom of a tank filled with a liquid, said screen having a preselected geometry of openings with hole patterns of non-uniform size, shape and orientation; (b) adding reinforcing fibers to the liquid to create a slurry; (c) raising the screen to the top of the tank causing the fibers to be deposited on the screen thereby generating a preform, said preselected geometry or openings in the screen causing the fibers to be deposited in preselected orientations related to the orientation of the holes in the screen; (d) removing the preform from the screen; (e) placing the preform in a mold; (f) injecting resin into the mold to impregnate the fibers in the preform to thereby form the desired structure; and (g) removing the structure from the mold.

Claim 2

A method of forming a structure from a fiber reinforced plastic preform which comprises: (a) placing a screen shaped to a desired preform configuration near the bottom of a tank filled with a liquid, said screen having a preselected geometry of openings with hole patterns of non-uniform size, shape and orientation; (b) adding reinforcing fibers to the liquid to create a slurry; (c) raising the screen to the top of the tank causing the fibers to be deposited on the screen thereby generating a preform, said preselected geometry or openings in the screen causing the fibers to be deposited in preselected orientations related to the orientation of the holes in the screen; (d) removing the preform from the screen; (e) placing the preform in a mold; (f) injecting resin into the mold to impregnate the fibers in the preform to thereby form the desired structure; and (g) removing the structure from the mold.

Claim 6

An apparatus for forming fiber reinforced plastic preforms comprising: (a) a tank having a top portion and a bottom portion, the tank containing a slurry of liquid and a mass of fibers; (b) a contoured screen having a predetermined configuration, said contoured screen containing openings and being disposed within said tank; (c) frame means for supporting the screen; (d) means for raising the contoured screen vertically toward the top portion of the tank at a sufficient rate to create a downward force which causes the slurry of liquid to pass through the openings in the screen whereby the fibers are deposited on the screen to form a preform having substantially the same configuration as the contoured screen and having a sufficient mass of fibers to form a fiber reinforced plastic part when injected with resin; and (e) vacuum pickup means for removing the preform from the screen, the pickup means having an engagement surface complimentary to the contoured screen.

Claim 7

An apparatus for forming fiber reinforced plastic preforms comprising: (a) a tank having a top portion and a bottom portion, the tank containing a slurry of liquid and a mass of fibers; (b) a contoured screen having a predetermined configuration, said contoured screen containing openings and being disposed within said tank; (c) frame means for supporting the screen; (d) means for raising the contoured screen vertically toward the top portion of the tank at a sufficient rate to create a downward force which causes the slurry of liquid to pass through the openings in the screen whereby the fibers are deposited on the screen to form a preform having substantially the same configuration as the contoured screen and having a sufficient mass of fibers to form a fiber reinforced plastic part when injected with resin; and (e) vacuum pickup means for removing the preform from the screen, the pickup means having an engagement surface complimentary to the contoured screen.

Claim 9

The apparatus for forming fiber reinforced plastic preforms comprising: (a) a tank containing a slurry of liquid and fibers; (b) a screen having a preselected geometry of openings with hole patterns of non-uniform size, shape and orientation; (c) frame means for supporting the screen; and (d) means for causing the slurry to flow through the screen and deposit the fibers on the screen, said preselected geometry of openings in the screen causing the fibers to be deposited in preselected orientations related to the orientation of the holes in the screen.

Claim 10

The apparatus for forming fiber reinforced plastic preforms comprising: (a) a tank containing a slurry of liquid and fibers; (b) a screen having a preselected geometry of openings with hole patterns of non-uniform size, shape and orientation; (c) frame means for supporting the screen; and (d) means for causing the slurry to flow through the screen and deposit the fibers on the screen, said preselected geometry of openings in the screen causing the fibers to be deposited in preselected orientations related to the orientation of the holes in the screen.

Claim 12

An apparatus for forming fiber reinforced plastic preforms comprising: (a) a tank containing a slurry of liquid and fibers; (b) a screen; (c) frame means for supporting the screen; (d) means for raising the screen to cause the fibers to be deposited on the screen; and (e) bubbler means located adjacent to and carried with the screen for mixing the liquid and fibers together to create a substantially even dispersion of the fibers in the slurry.

Claim 13

An apparatus for forming fiber reinforced plastic preforms comprising: (a) a tank containing a slurry of liquid and fibers; (b) a screen; (c) frame means for supporting the screen; (d) means for raising the screen to cause the fibers to be deposited on the screen; and (e) bubbler means located adjacent to and carried with the screen for mixing the liquid and fibers together to create a substantially even dispersion of the fibers in the slurry.