Abstract: A preform of complex three-dimensional shape is prepared by a directed fiber preforming process in which a flow of chopped fibers are drawn by vacuum against a foraminous screen having a shape corresponding to that of preform to be made. The screen has depressed regions that are susceptible to excessive build-up of the chopped fibers. To counteract the build-up in these areas, a baffling system is provided behind the screen having baffle plates which are extendable into and out of blocking engagement with the backside of the problem depressed regions to govern the vacuum draw and hence the deposit and build-up of fibers across the depressed regions.

Abstract: A process for producing a reinforced plastic motor vehicle bumper includes the steps of placing a woven roving (17) on a center section of a preform screen (10) that is retained by a vacuum draw from a suction fan (16). Chopped glass fibers (20) and a curable binder are sprayed onto the preform screen and woven roving. A second layer (22) of woven roving is placed onto the center section of chopped glass and first layer (17) of woven roving. Either the excess trim (39) is trimmed by a cutting die (50) before the preform is cured or the die is first cured and then the excess trim is trimmed by a cutter using a plastic base (35) in the screen that circumscribes the contoured section of the preform screen.

Abstract: A process for producing a preform includes the steps of retaining a glass fiber fabric (40) on a foraminous screen (14) by use of a vacuum draw and depositing chopped glass fibers (19) onto the glass fiber fabric with a binder that cures in place. The vacuum draw retains the deposited materials in place until the binder is cured.

Abstract: A process for producing a preform (44) includes pretreating roving by submerging it in a tank (18) and cooling the binder (20) on the glass fibers before the glass fibers are chopped. The fibers and solidified binder are then chopped and deposited onto a preform screen (32). Heat is applied to soften the binder that is on the chopped glass fibers and cooled to set the binder and form the preform on the screen.

Abstract: A process for producing a reinforced plastic motor vehicle bumper includes the steps of placing a woven roving (17) on a center section of a preform screen (10) that is retained by a vacuum draw from a suction fan (16). Chopped glass fibers (20) and a curable binder are sprayed onto the preform screen and woven roving. A second layer (22) of woven roving is placed onto the center section of chopped glass and first layer (17) of woven roving. Either the excess trim (39) is trimmed by a cutting die (50) before the preform is cured or the die is first cured and then the excess trim is trimmed by a cutter using a plastic base (35) in the screen that circumscribes the contoured section of the preform screen.

Abstract: A preform (11) is formed from sprayed binder and chopped fibers from respective nozzles (21) and (18) onto a foraminous screen (14). A plurality of nozzles (33) are circumferentially spaced about nozzles (21) and (18) and provide heated air to cure the binder. The nozzles (18),(21), and (33) are affixed to each other and are mounted onto a gantry (32) for relative motion with respect to the screen (14). The heated air cures the preform (11) simultaneously with it formation.