Process of making a fiber-reinforced plastic sheet having a gradient of fiber bundle size within the sheet
AssigneeNKK Corporation
InventorsMasato Hirasaka, Yoshiaki Fujiwara
Life of this patent
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Abstract
This invention relates to a fiber reinforced plastic sheet having a gradient layer structure wherein the number of reinforcing fibers continuously varies and a process for producing the same by spreading a mixture of the fibers different in the number of filaments over the traveling zone of a conveyor and then pressing it while it contains a resin. The fiber reinforced plastic sheet of the invention is excellent in smooth appearance, fluidity during molding to an article, fiber filling ability into a complex form portion of an article and mechanical strength and can be produced inexpensively.
Claims6
A process for producing a fiber reinforced plastic sheet which comprises separating discontinuous reinforcing fibers which are being opened or have been opened to form a distribution of the fibers different in the number of filaments by spreading them over a traveling zone of a conveyor at an angle except the vertical direction toward the traveling zone together with airflow to form a gradient layer utilizing the difference in the weight of each fiber, superposing a resin on said gradient layer, and pressing the superposed resin under heating to form the fiber reinforced plastic sheet, said fibers being arranged in a gradient layer structure which continuously varies from a layer of the fibers having a greater number of lighter filaments to a layer of the fibers having a lesser number of heavier filaments as compared to the number of lighter filaments.
A process for producing a fiber reinforced plastic sheet which comprises separating discontinuous reinforcing fibers which are being opened or have been opened to form a distribution of the fibers different in the number of filaments by spreading them over a traveling zone of a conveyor at an angle except the vertical direction toward the traveling zone together with airflow to form a gradient layer utilizing the difference in the weight of each fiber, interposing a resin in said gradient layer, and pressing the interposed resin under heating to form the fiber reinforced plastic sheet, said fibers being arranged in a gradient layer structure which continuously varies from a layer of the fibers having a greater number of lighter filaments to a layer of the fibers having a lesser number of heavier filaments as compared to the number of lighter filaments.
Dependencies are inferred from the claim text.