Method for manufacturing fiber-reinforced plastic product

Abstract

The invention relates to a method for producing a fiber-reinforced plastic product. The method for producing the fiber-reinforced plastic product comprises the following steps that a fiber preform is prepared on a mold; a first flow guide net, a second flow guide net, a first piece of demolding cloth and a second piece of demolding cloth are laid for the fiber preform; the fiber preform is sealed and made into a vacuum system through air extraction; resin is made to permeate the first piece of demolding cloth and soak the fiber preform from bottom to top by means of the first flow guide net; the resin is made to permeate the second piece of demolding cloth and soak the fiber preform from top to bottom by means of the second flow guide net; and the fiber preform soaked with the resin is obtained, and the fiber-reinforced plastic product is obtained finally. The method for producing the fiber-reinforced plastic product is characterized in that a first film is arranged on the side, close to the resin injection position, of the fiber preform so as to cover at least part of the first piece of demolding cloth, the first flow guide net and the fiber preform, and after the resin is supplied to the first flow guide net, the resin is supplied to the second flow guide net when the flowing area of the resin on the fiber preform is beyond the area covered by the first film.

Description

technical field [0001] The present invention relates to a method of manufacturing fiber reinforced plastic articles. Specifically, the present invention especially relates to a method for forming a fiber-reinforced plastic product with a relatively large thickness by using a vacuum infusion process, which is especially suitable for compounding fiber-reinforced resins such as polyurethane resin, epoxy resin and unsaturated resin. Material products are subjected to vacuum infusion molding. Background technique [0002] The vacuum infusion process has been widely used in the molding process of fiber reinforced resin composite products. Generally speaking, the process is as follows: First, a certain number of layers of fibers are laid on the mold according to the design requirements to form a fiber prefabricated body. The fiber prefabricated body may contain sandwich materials such as foam and balsa wood or other reinforcing materials. In addition, process materials such as re...

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Problems solved by technology

[0007] However, this method also has the following limitations: since the resin needs to infiltrate the entire fiber preform from the bottom up, the resin needs to flow through the entire thickness of the fiber preform

[0009] An important drawback of this method is that the resin flows from the top and bottom of the fiber preform to the middle at the same time from the beginning of infusion

[0011] This method avoids the problem that the intermediate fibers of the fiber preform cannot be fully infiltrated due to simultaneous injection of resin above and below the fiber preform, but it also brings some new technical problems: first, the glue injection port and the The air suction port will be pressed tightly on the fiber preform under the action of atmospheric pressure to form an impression, which will cause the fiber to bend and affect the performance and surface quality of the product; It is connected with the guide net above the fiber preform to enhance the air discharge speed in the fiber preform at the initial stage of resin injection

[0013] A significant defect of this process is that the glue injection tube set above the fiber preform needs to be suspended above the fiber preform to avoid direct contact between the glue injection tube and the glue injection port and the fiber preform to form impressions, which will eventually affect the performance and surface of the product quality

Practice has proved that it is very difficult to implement this method in the manufacturing process, so it is difficult to apply to actual production

In addition, this method adopts the method of setting a single-layer air extraction channel on the side of the top of the fiber preform away from the glue injection port. Due to the inhomogeneity of the resin flow, the air extraction channel is easily penetrated from the bottom of the fiber preform. The air near the channel cannot be continuously expelled due to the blockage of the resin coming up

At the same time, since the position of the air extraction channel is farthest from the resin injection port, that is, the part of the entire fiber preform that can be infiltrated last, the result that the air extraction channel is blocked by the resin is that the glass fiber near the position of the air extraction channel is very easy to Formation of dry glass fibers or white spots due to insufficient air removal

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