JP6971643B2 - Method for manufacturing fiber molded product using fiber laminated sheet member - Google Patents

Description

The present invention relates to a fiber laminated sheet member and a method for manufacturing a fiber molded product using the fiber laminated sheet, particularly a lightweight and high-strength carbon fiber sheet member and a method for manufacturing a fiber molded product using the same.

Attention is being paid to carbon fiber molded products made of carbon fiber reinforced resin, which is generally called CFRP (Carbon Fiber Reinforced Plastics). Since this carbon fiber reinforced resin generally has both a small specific gravity and a large mechanical strength, the molded product is used as a substitute for a steel plate part of a vehicle, for example. As such a carbon fiber molded product, for example, there is one described in Patent Document 1 below. In this carbon fiber molded product, a carbon fiber sheet made of carbon fiber woven fabric is impregnated with a thermosetting resin to form a prepreg, and a thermoplastic resin film is bonded to both sides thereof to form a carbon fiber laminated sheet member, and the carbon fiber laminated product is formed. The sheet member is premolded into a specified shape by hot press molding, the premolded product is set in a mold, and the thermoplastic resin is injection-molded from the side opposite to the surface of the molded product. In this carbon fiber molded product, the carbon fiber can be seen through through a transparent thermoplastic resin or a thermosetting resin, and the design is excellent.

Japanese Unexamined Patent Publication No. 10-138354

As the carbon fiber molded product, as represented by the above-mentioned Patent Document 1, a carbon fiber sheet made of a carbon fiber woven fabric, a so-called cloth, is used. However, carbon fiber fabrics are generally less flexible or less flexible and therefore difficult to mold. Therefore, when a carbon fiber laminated sheet member using a carbon fiber woven sheet is set in a mold and molded, for example, kinks and wrinkles are likely to occur, productivity is low, and designability is also likely to deteriorate. On the other hand, a technique of injection molding a thermoplastic resin (CFRTP: Carbon Fiber Reinforced Thermo Plastics) containing carbon fibers is also widely used, but the carbon fibers have poor design because the eyes are unclear.

The present invention has been made in view of the above problems, and an object thereof is to provide a fiber laminated sheet member having excellent design and productivity, and a method for manufacturing a fiber molded product using the fiber laminated sheet member. To do.

Fiber lamination sheet member order to achieve the above object,
In a fiber laminated sheet member in which both sides of a fiber sheet are coated with a film, the fiber sheet is made of a knitted reinforcing fiber, and at least one of the films coated on both sides of the fiber sheet is transparent. The film coated on both sides of the fiber sheet is characterized by having moldability.

According to this configuration, the fiber sheet made of a knitted reinforcing fiber has excellent flexibility and flexibility and is easy to mold. Therefore, for example, when a fiber laminated sheet member is set in a mold and molded, wrinkles and wrinkles are formed. The film that is coated on both sides of the fiber sheet has moldability, so that it is highly productive, and the reinforcing fibers can be seen through the transparent film, so that it is also excellent in designability.

Method for producing a fiber molded article using the fibrous laminate sheet member for achieving the above object, the fiber lamination sheet member was set in a die, only one transparent film which is coated on both surfaces of the fiber sheet only the side opposite to the said transparent film in the case, or only one of the film side if both of the film to be coated on both surfaces of the fiber sheet is transparent, injection molding a thermoplastic resin It is characterized by.

According to this configuration, a layer of a thermoplastic resin that exhibits sufficient strength after curing is formed on the back side or the inside of the fiber laminated sheet member, so that the fiber molded product using the fiber laminated sheet member has a specified strength. Can be granted.

Further , it is characterized in that the fiber laminated sheet member is premolded in a premolding die before injection molding of the thermoplastic resin.

According to this configuration, by premolding the fiber laminated sheet member in the premolding mold, the fiber laminated sheet member is formed into the surface shape or the outer shape of the fiber molded product before the thermoplastic resin is injection-molded. Therefore, the fiber molded product using the fiber laminated sheet member can be surely formed into a specified shape.

Further , the thermoplastic resin is characterized by containing reinforcing fibers.

According to this configuration, the thermoplastic resin containing the reinforcing fiber has higher strength after curing than the thermoplastic resin not containing the reinforcing fiber. Therefore, by incorporating the reinforcing fiber in the thermoplastic resin, the fiber molded product It is possible to further improve the strength of the resin.

Further , in a fiber laminated sheet member in which one surface of a fiber sheet is coated with a film and the other surface is coated with a sheet, the fiber sheet is made of a knitted reinforcing fiber, and one surface of the fiber sheet is covered with the fiber sheet. The film to be coated is transparent and has moldability, and the sheet coated on the other surface of the fiber sheet is a thermoplastic resin sheet.

According to this configuration, a fiber sheet made of a knitted reinforcing fiber has excellent flexibility and flexibility and is easy to mold. Therefore, for example, when a fiber laminated sheet member is set in a thermoforming die and hot press molded. Since the film is moldable and the sheet is a thermoplastic resin sheet, it is highly productive during thermoforming, and the reinforcing fibers can be seen through the transparent film. It is also excellent in design because it can be seen. Further, a strong molded product can be obtained only by hot press molding the fiber laminated sheet member.

Further , the thermoplastic resin sheet is characterized by containing reinforcing fibers.

According to this configuration, the thermoplastic resin containing the reinforcing fibers has higher strength after curing than the thermoplastic resin not containing the reinforcing fibers. Therefore, by incorporating the reinforcing fibers in the thermoplastic resin sheet, the fibers are formed. The strength of the fiber molded product using the laminated sheet member can be further improved.

Also, it sets the fiber lamination sheet member in the thermoforming die, characterized by hot press molding.

According to this configuration, a strong fiber molded product can be obtained only by hot press molding the fiber laminated sheet member.

As described above, according to the present invention, a fiber sheet made of a knitted reinforcing fiber has excellent flexibility and flexibility and is easy to mold. Therefore, for example, a fiber laminated sheet member is set in a mold and molded. It is less likely to wrinkle or wrinkle, and the film or sheet that coats the fiber sheet has moldability, so it is highly productive. Moreover, the reinforcing fibers can be seen through the transparent film, which makes it more designable. Is also excellent. In addition, since it is easy to mold the fiber molded product, the labor and time required for molding can be reduced, and the cost can be reduced.

It is explanatory drawing which shows 1st Embodiment of the fiber laminated sheet member of this invention. It is explanatory drawing of the premolding in the manufacturing method of the fiber molded article using the fiber laminated sheet member of FIG. It is explanatory drawing of the manufacturing method of the fiber molded article using the preformed article of FIG. It is explanatory drawing which shows the 2nd Embodiment of the fiber laminated sheet member of this invention. It is explanatory drawing of the manufacturing method of the fiber molded article using the fiber laminated sheet member of FIG.

Hereinafter, embodiments of the fiber laminated sheet member of the present invention and a method for manufacturing a fiber molded product using the fiber laminated sheet member will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram of a laminating process showing a first embodiment of the fiber laminated sheet member of the present invention. In this embodiment, films 14 and 16 are joined to both sides of a fiber sheet 12 made of a knitted reinforcing fiber to form a three-layer fiber laminated sheet member 10. In this embodiment, carbon fiber is used as the reinforcing fiber constituting the fiber sheet 12. Further, in this embodiment, the fiber sheet 12 and the films 14 and 16 are joined by roll molding. For specific bonding, welding (fusing), pressure bonding, adhesion with an adhesive, or the like is selected depending on the material of the fiber sheet 12, the films 14, and 16 and the application of the molded product.

The carbon fiber knitted fabric constituting the fiber sheet 12 of this embodiment has various knitting methods (stitches) according to the use of the fiber molded product using the fiber laminated sheet member 10 and the design required for the fiber molded product. ) Can be selected. Traditionally, it has been considered difficult to knit carbon fibers, but in recent years, not only carbon fibers can be knitted, but also various knitting methods (stitches) have become possible. Since the stitches of the carbon fiber knitted fabric greatly affect the design of the carbon fiber molded product, the stitch, that is, the knitting method is selected according to the use of the fiber molded product and the designability required for the fiber molded product. The stitches of carbon fiber are determined by the carbon fiber knitting machine and the knitting method using it.

A skin film 14 through which at least the reinforcing fibers (eyes) of the fiber sheet 12 can be seen through is bonded to one surface of the fiber sheet 12, specifically, the surface (outer surface) of the fiber molded product. For the skin film 14, a highly transparent acrylic resin film such as polymethylmethacrylate (PMMA) or polymethacrylate (PMA) can be adopted. The acrylic resin is included in the thermoplastic resin that can be heat-press molded, but it is also possible to use a thermosetting resin film depending on the application and function. As will be described later, the skin film 14 has moldability that allows premolding when the fiber laminated sheet member 10 in a state where the skin film 14 is coated on the surface of the fiber sheet 12 is preformed. There is a need. Further, the skin film 14 is a transparent film in which the reinforcing fibers (eyes) of the fiber sheet 12 can be seen through in order to enhance the design of the fiber molded product. It may not be colorless depending on the intended use of the fiber molded product.

The base film 16 that is the base material of the sheet member 10 is bonded to the other surface of the fiber sheet 12, specifically, the back surface (inner side surface) of the fiber molded product. The substrate film 16 may be any film as long as it is made of, for example, a thermoplastic resin film and has moldability that enables premolding of the fiber laminated sheet member 10 described later, for example, PE. A packing film made of (polyethylene) or PP (polypropylene) can be used. For example, the thinner the substrate film 16, the easier it is to preform, which will be described later. However, in order to maintain the shape after preforming, the substrate film 16 after preforming needs to have a specified strength. A film thickness that can achieve the specified strength is required. The substrate film 16 does not have to be transparent, but may be transparent.

These fiber sheets 12 and films 14 and 16 are, for example, pulled out from a state of being wound in a roll shape, charged into a roll molding machine, pressed by the roll molding machine, and joined as a fiber laminated sheet member 10. .. When the fiber sheet 12 and the films 14 and 16 are continuous bodies, the fiber laminated sheet member 10 is also a continuous body, and may be wound into, for example, a roll. Further, the continuous sheet member 10 may be cut into predetermined lengths and stacked as, for example, a rectangular sheet body.

Since the fibers of the fiber sheet 12 can be seen through the surface of the fiber laminated sheet member 10 of this embodiment, when the sheet member 10 is manually handled during pre-molding or finished product molding, which will be described later, the sheet member 10 can be seen through. There is no problem in aligning the fiber grain of the fiber sheet 12 in the direction required for the molded product. On the other hand, in the state of the fiber laminated sheet member 10, marks such as recesses and reflections that can mechanically, optically, and electrically detect, recognize, and identify the eyes of the fibers of the fiber sheet 12 or the directions of the eyes. -By providing the transmissive portion, the conductive portion, and the like, it is possible to automatically set the seat member 10 in the subsequent process.

The fiber laminated sheet member 10 thus produced is cut out to, for example, a specified size, set in the premolding die 20 shown in FIG. 2, and premolded. In the preforming, heating may be performed according to the material of the sheet member 10 and the required preforming shape. As described above, when the films 14 and 16 are thermoplastic resins, hot pressing with the premolding die 20 facilitates preforming. In this premolding, the skin film 14 of the fiber laminated sheet member 10 is molded so as to be the surface (outer surface) of the fiber molded product (finished product).

The preformed product of the resin laminated sheet member 10 preformed in this way is set in the molding die 22 shown in FIG. 3, and the back side of the fiber molded product (finished product), that is, the resin laminated sheet member 10 is set. The thermoplastic resin 18 is injection-molded on the substrate film 16 side of the above. The thermoplastic resin 18 is cured on the back side of the molded product, thereby imparting a specified strength to the fiber molded product. The thermoplastic resin 18 may contain carbon (reinforced) fibers. That is, in that case, CFRTP is injection-molded on the back side of the premolded product. As is well known, CFRTP containing carbon fiber exerts a large strength after curing. Therefore, by forming a CFRTP molded layer on the back side of the fiber molded product, the fiber molded product is imparted with even greater strength. Will be done. After the thermoplastic resin 18 is cured, the mold is released and the molded product is taken out. The carbon (reinforced) fiber contained in the thermoplastic resin 18 may be a discontinuous carbon (reinforced) fiber.

In general CFRP, a number of layers of carbon fiber sheets made of carbon fiber woven fabric are stacked and set in a mold, and a thermosetting resin is injected into the mold. The thermosetting resin impregnates the carbon fiber sheet and cures to form a fiber molded product. Preliminary shaping may be applied to the laminated carbon fiber sheets before setting in the mold. In addition, the pressure inside the mold may be reduced at the same time as the injection of the thermosetting resin. Although the carbon fiber itself has great strength, the strength of the fiber molded product is ensured by stacking multiple layers of the carbon fiber sheet.

On the other hand, like general fiber woven fabrics, carbon fiber woven fabrics lack flexibility and flexibility. Therefore, when the carbon fiber sheet is folded and set in the mold, the sheet is liable to wrinkle or wrinkle, especially in a place where the carbon fiber sheet is folded from two directions, and the productivity is lowered and the design is apt to be reduced. In addition, laminating and setting the carbon fiber sheet on the molding die or the preliminary shaping die is generally performed manually, which is time-consuming and time-consuming. Further, since it takes time to inject and cure the thermosetting resin, the production of the fiber molded product requires labor and time, the productivity is low, and as a result, the molded product becomes expensive.

On the other hand, in the method for manufacturing a fiber molded product using the fiber laminated sheet member 10 and the fiber laminated sheet member 10 of this embodiment, a transparent skin film 14 is formed on one surface of the fiber sheet 12 made of a carbon fiber knitted fabric. The fiber laminated sheet member 10 is formed by joining the base film 16 to the other surface, and after preforming the sheet member 10, the sheet member 10 is set in the molding mold 22 and heated to the back side of the fiber molded product. The plastic resin 18 is injection molded. The fiber sheet 12 made of a knitted carbon fiber is rich in flexibility and flexibility and is easy to mold. Therefore, for example, wrinkles and wrinkles are less likely to occur during pre-molding, and the strength of the fiber-molded product does not decrease. Does not decrease.

As described above, according to this embodiment, the skin film 14 through which the reinforcing fibers can be seen is bonded to one surface of the fiber sheet 12 made of knitted reinforced (carbon) fibers, and the fiber laminated sheet member is bonded to the other surface. Since the base film 16 constituting the base of 10 is joined to form the fiber laminated sheet member 10, the fiber sheet 12 made of knitted reinforcing fibers has excellent flexibility and flexibility and is easy to mold. Therefore, the fiber laminated sheet Even when the member 10 is set in the premolding mold 20 and premolded, wrinkles and wrinkles are less likely to occur, so that the productivity of the fiber-molded product is improved, and the reinforcing fibers can be seen through the skin film 14. Therefore, it is also excellent in design.

Further, by setting the fiber laminated sheet member 10 in the molding die 22 and injection molding the thermoplastic resin 18 on the substrate film 16 side, the fiber molded product can be imparted with the specified strength.

Further, by pre-molding the fiber laminated sheet member 10 in the pre-molding die 20 before the injection molding of the thermoplastic resin 18, the fiber-molded product can be surely formed into a specified shape.

Further, by containing the reinforcing fiber in the thermoplastic resin 18, it is possible to further improve the strength of the fiber molded product.

Next, a second embodiment of the fiber laminated sheet member of the present invention and the method for manufacturing a fiber molded product using the fiber laminated sheet member will be described. FIG. 4 is an explanatory diagram of a laminating process showing the fiber laminated sheet member of this embodiment. Also in this embodiment, for example, by roll molding, the reinforcing fibers can be seen through one surface of the fiber sheet 12 made of the same carbon fiber knitted fabric as in the first embodiment. In this embodiment, the thermoplastic resin sheet 24 is bonded to the other surface of the fiber sheet 12. Carbon fibers may be contained in the thermoplastic resin of the thermoplastic resin sheet 24. That is, the CFRTP sheet may be joined. In this embodiment, as will be described later, since the fiber-molded product is manufactured by hot-press molding the fiber laminated sheet member 10, the properties and specific features such that the strength of the fiber-molded product can be obtained by hot-press molding. Use a thick thermoplastic resin sheet or CFRTP sheet. As the fiber sheet 12 and the skin film 14, the same ones as those in the first embodiment described above can be used. Further, as in the first embodiment, it is also possible to provide a mark capable of detecting the stitches of the fibers of the fiber sheet 12 or the direction of the stitches.

In this embodiment, as shown in FIG. 5, the fiber laminated sheet member 10 obtained in the laminating step of FIG. 4 is hot-press molded in a thermoforming die 26 to obtain a molded product. The fiber laminated sheet member 10 of this embodiment has a laminated structure of a skin film 14, a fiber sheet 12, and a thermoplastic resin sheet 24, and in particular, the thermoplastic resin sheet 24 is heat-molded by hot press molding. When the thermoplastic resin sheet 24, and in some cases, the thermoplastic resin sheet 24 containing carbon fibers, is cured, the fiber molded product is given the specified strength. Therefore, after curing, the fiber molded product is taken out by molding. As described above, in this embodiment, in addition to the effect of the first embodiment, there is an effect that a fiber molded product having a specified strength can be obtained only by hot press molding the fiber laminated sheet member 10. ..

As described above, according to this embodiment, the skin film 14 through which the reinforcing fibers can be seen is bonded to one surface of the fiber sheet 12 made of knitted reinforcing (carbon) fibers, and the thermoplastic resin sheet is bonded to the other surface. Since the fiber laminated sheet member 10 is formed by joining 24 to the fiber laminated sheet member 10, the fiber sheet 12 made of knitted reinforcing fibers has excellent flexibility and flexibility and is easy to mold. Even when the fibers are set in the above and hot press molded, wrinkles and wrinkles are less likely to occur, so that the productivity of the molded product is improved, and the fibers can be seen through the skin film 14, so that the design is also excellent. Further, a strong molded product can be obtained only by hot press molding the fiber laminated sheet member 10.

Further, by containing the reinforcing fiber in the thermoplastic resin sheet 24, the strength of the fiber molded product can be further improved.

Further, by setting the fiber laminated sheet member 10 in the thermoforming mold and hot press molding, a strong molded product can be obtained only by hot press molding the fiber laminated sheet member 10.

It goes without saying that the present invention includes various embodiments not described above. Therefore, the technical scope of the present invention is defined only by the matters specifying the invention described in the claims that are valid from the above description.

10 Fiber laminated sheet member 12 Fiber sheet 14 Skin film 16 Base film 18 Thermoplastic resin 20 Pre-molding mold 22 Molding mold (mold)
24 Thermoplastic resin sheet 26 Thermoforming mold

Claims (3)

The fiber sheet is composed of a knitted fabric in which reinforcing fibers are knitted by a knitting method selected according to a desired design , and at least one of the films coated on both sides of the fiber sheet is transparent and the fiber. A fiber laminated sheet member having a formability as a film coated on both sides of the sheet is set in a mold, and when only one of the films coated on both sides of the fiber sheet is transparent, it is opposite to the transparent film. use only on the side, or only one of the film side if both of the film to be coated on both surfaces of the fiber sheet is transparent, the fiber lamination sheet member characterized by injection molding a thermoplastic resin The manufacturing method of the fiber molded product that was used. Before the injection molding of the thermoplastic resin, method for producing a fiber molded article using the fibrous laminate sheet member according to claim 1, characterized in that preforming the fibrous laminate sheet member in preforming die .. The method for producing a fiber molded product using the fiber laminated sheet member according to claim 1 or 2 , wherein the reinforcing fiber is contained in the thermoplastic resin.

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