JP2021171970A - Method for manufacturing fiber-reinforced resin molded product and fiber-reinforced resin molded product - Google Patents

Abstract

To achieve both surface smoothness and productivity when manufacturing a fiber-reinforced resin molded product.SOLUTION: A method for manufacturing a fiber-reinforced resin molded product 102 in which press forming is performed by laminating a fabric-like body 11, composed by combining a fiber substrate 11a with a predetermined resin composition 11b, and a resin sheet 12 having a composition different from the resin composition 11b, comprises a preparation step of preparing the fabric-like body 11 using a resin composition 11b having a lower melting point compared to the resin sheet 12, and the resin sheet 12; and a press step of performing press forming, with laminating the resin sheet 12 on a surface layer side of the fabric-like body 11 in a heated state at a temperature (pressing temperature T3) between a melting point (a first melting point T1) of the resin composition 11b and a melting point (a second melting point T2) of the resin sheet 12.SELECTED DRAWING: Figure 6

Description

The present disclosure relates to a method for producing a fiber-reinforced resin molded product and a fiber-reinforced resin molded product.

For example, Patent Document 1 discloses a resin molded product obtained by attaching a resin skin material having an adhesive layer to a molded body of a fiber base material made of carbon fiber, glass fiber, or a composite fiber thereof.

Specifically, the resin molded product disclosed in Patent Document 1 is obtained by laminating a molded product in which fibers and resins are mixed and a resin skin material having an adhesive layer, and pressurizing the laminate. It is designed to be manufactured.

JP-A-2017-65230

By the way, a molded product made of a resin containing a fiber base material as described in Patent Document 1 (so-called fiber reinforced resin molded product) has an uneven surface due to the fiber base material, so that the surface is smooth. There was room for improvement in sex.

Therefore, conventionally, after molding a fiber-reinforced resin molded product, the surface smoothness is improved by repeating a step of applying a surfacer for filling the unevenness of the surface and a step of polishing the surface after the surfacer is dried. It was supposed to be secured.

However, polishing repair using a surfacer is inconvenient for ensuring the productivity of the molded product, although the surface smoothness is ensured.

The technique disclosed herein has been made in view of the above points, and an object thereof is to achieve both surface smoothness and productivity in the production of a fiber-reinforced resin molded product.

The first aspect of the present disclosure is a fiber to be press-molded by laminating a cloth-like body formed by combining a predetermined resin composition with a fiber base material and a resin sheet having a composition different from the resin composition. It relates to the manufacturing method of the reinforced resin molded article. This production method comprises a preparatory step of preparing the cloth-like body and the resin sheet, which are made of a resin composition having a lower melting point than the resin sheet as the resin composition, and the cloth-like body. The resin sheet is laminated on the surface layer side of the resin sheet, and is provided with a press step of performing press molding while being heated to a temperature between the melting point of the resin composition and the melting point of the resin sheet.

Instead of the polishing repair process using a surfacer, the inventors of the present application laminate a resin sheet on a cloth-like body containing textile equipment and a resin composition, and press-mold the laminated body in a heated state. I considered that. In this case, a fiber-reinforced resin having the resin composition as the central layer is formed, and the resin sheet becomes a surface layer that imparts smoothness to the fiber-reinforced resin.

However, in such a configuration, the fiber base materials in the cloth-like body interfere with each other in the pressing process, so that a repulsive force is generated in the direction opposite to the compression direction by the press, and the repulsive force causes the fiber group. A new problem has been discovered in which the material can penetrate the resin sheet.

As a result of diligent studies on this problem, the inventors of the present application have devised a manufacturing method in consideration of the thermal characteristics of the resin composition constituting the cloth-like body and the resin sheet laminated on the cloth-like body. We came up with a new idea and came to this disclosure.

Specifically, according to the first aspect, in the preparation step, a cloth-like body made of a resin composition having a melting point lower than that of the resin sheet is prepared. Subsequently, in the pressing step, press molding is performed in a state of being heated to a temperature between the melting point of the resin composition and the melting point of the resin sheet.

In this configuration, the resin composition is melted, while the resin sheet is press-molded in a state where it is softened but not melted, which is caused by the repulsive force in the cloth-like body. Penetration of the fiber base material can be suppressed. As a result, the fiber-reinforced resin molded product can be manufactured without penetrating the fiber base material from the surface, so that a molded product having excellent surface smoothness can be realized. Further, the manufacturing method according to the first aspect does not require a polishing repair step using a surfacer, and thus is excellent in productivity.

As described above, according to the present disclosure, both surface smoothness and productivity can be achieved in the production of the fiber-reinforced resin molded product.

Further, according to the second aspect of the present disclosure, in the pressing step, the resin is compared with the melting point of the resin sheet with respect to the intermediate value between the melting point of the resin composition and the melting point of the resin sheet. Press molding may be performed in a state of being heated to a temperature close to the melting point of the composition.

According to the second aspect, press molding can be performed with the fiber base material pressed by the resin sheet. As a result, the penetration of the fiber base material is suppressed, which is advantageous in improving the surface smoothness.

Further, according to the third aspect of the present disclosure, the pressing step is heated to a temperature close to an intermediate value between the melting point of the resin composition and the melting point of the resin sheet as compared with the melting point of the resin composition. Press molding may be performed in this state.

According to the third aspect, press molding can be performed with the fiber base material pressed by the resin sheet. As a result, the penetration of the fiber base material is suppressed, which is advantageous in improving the surface smoothness. Further, by performing press molding in a state of being heated to a temperature close to the intermediate value, the degree of softening of the resin can be promoted and the bonding strength can be improved.

Further, according to the fourth aspect of the present disclosure, in the pressing step, a part of the fiber base material penetrates into the boundary portion between the resin layer made of the cloth-like body and the resin layer made of the resin sheet. It may be press-molded so as to cause.

According to the fourth aspect, by intentionally invading a part of the fiber base material into the boundary portion, the anchor effect can be exerted and the bonding strength between the cloth-like body and the resin sheet can be improved. can. Further, by keeping the resin sheet invading not the entire area but the boundary portion, it is also advantageous in suppressing the penetration of the fiber base material.

A fifth aspect of the present disclosure is a fiber reinforced plastic obtained by laminating a cloth-like body formed by combining a predetermined resin composition with a fiber base material and a resin sheet having a composition different from that of the resin composition. Related to resin molded products. In this fiber-reinforced resin molded product, the melting point of the resin composition is lower than that of the resin sheet, and the cloth-like body and the resin sheet are laminated so that the resin sheet is located on the surface layer side. , A part of the fiber base material penetrates into the boundary between the resin layer made of the cloth-like body and the resin layer made of the resin sheet.

According to the fifth aspect of the present disclosure, as the resin composition constituting the cloth-like body, a resin composition having a melting point lower than that of the resin sheet is prepared. As a result, by performing press molding while heating to a temperature between the melting point of the resin composition and the melting point of the resin sheet, the fiber-reinforced resin molded product can be produced without penetrating the fiber base material from the surface. Can be manufactured. Therefore, it is possible to realize a molded product having excellent surface smoothness. Further, the molded product according to the sixth aspect is excellent in productivity because it does not require a polishing repair step using a surfacer.

Further, according to the fifth aspect, by intentionally invading a part of the fiber base material into the boundary portion, the anchor effect is exerted and the bonding strength between the cloth-like body and the resin sheet is improved. be able to. Further, it is possible to suppress the penetration of the fiber base material by keeping the resin sheet invading not the entire area but the boundary portion.

Further, according to the sixth aspect of the present disclosure, the fiber-reinforced resin molded product according to the fifth aspect may be an outer panel part of an automobile.

In general, the outer panel parts of an automobile are required to have surface smoothness from the viewpoint of their design, and are required to be productive from the viewpoint of mass-produced products. The present disclosure is useful in that it can meet those demands.

As described above, according to the present disclosure, both surface smoothness and productivity can be achieved in the production of a fiber-reinforced resin molded product.

FIG. 1 is a diagram illustrating a manufacturing apparatus for a fiber-reinforced resin molded product. FIG. 2 is a flowchart illustrating a method for manufacturing a fiber-reinforced resin molded product. FIG. 3 is a schematic view illustrating a method for producing a fiber-reinforced resin molded product. FIG. 4 is a schematic view illustrating the internal structure of the fiber reinforced resin molded product. FIG. 5 is a cross-sectional view showing an example of a fiber reinforced resin molded product. FIG. 6 is a diagram illustrating an outer panel component made of a fiber reinforced resin molded product.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The following description is an example.

FIG. 1 is a diagram illustrating a manufacturing apparatus 1 of a fiber-reinforced resin molded product 102. FIG. 2 is a flowchart illustrating a method for manufacturing the fiber-reinforced resin molded product 102. FIG. 3 is a schematic view illustrating a method for manufacturing the fiber-reinforced resin molded product 102. FIG. 4 is a schematic view illustrating the internal structure of the fiber reinforced resin molded product 102. FIG. 5 is a cross-sectional view showing an embodiment of the fiber reinforced resin molded product 102. FIG. 6 is a diagram illustrating an outer panel component made of the fiber reinforced resin molded product 102.

The manufacturing method according to the present embodiment is a method for manufacturing the fiber-reinforced resin molded product 102. In this production method, a laminated body obtained by laminating a cloth-like body 11 formed by combining a fiber base material 11a and a predetermined resin composition 11b and a resin sheet 12 having a composition different from the resin composition 11b is laminated. The 101 is press-molded (see FIGS. 3 to 4 and the like).

The fiber-reinforced resin molded product 102 according to the present embodiment is an outer panel component of an automobile 1000. The outer panel parts include, for example, a bonnet 1001 and a fender panel 1002 among the parts constituting the automobile 1000 (see FIG. 6). In addition, the outer panel parts suitable for using the fiber reinforced resin molded product 102 include parts that require smoothness, light weight, and high rigidity, such as a door panel, a rear end panel, a side frame outer, and a rear wing of an automobile 1000. ..

<Manufacturing equipment for fiber reinforced plastic molded products>
The manufacturing apparatus 1 of the fiber-reinforced resin molded product 102 according to the present embodiment is a mold (molding mold) for obtaining the fiber-reinforced resin molded product 102 as a press-molded product, that is, an upper mold 2 and a lower mold for press molding. 3 is provided. The upper mold 2 is fixed to the upper mold holder 4. A slider (not shown) for raising and lowering the press machine is attached to the upper mold holder 4. The lower mold 3 is fixed to the lower mold holder 5. The upper mold 2 and the lower mold 3 have a molding surface corresponding to the fiber reinforced resin molded product 102.

Further, the upper die 2 is provided with a refrigerant passage 8 to which a liquid refrigerant (for example, cooling water) for cooling the laminated body 101 in a pressed state is supplied. Similarly, the lower mold 3 is provided with a refrigerant passage 9 to which a liquid refrigerant (for example, cooling water) for cooling the laminated body 101 in a pressed state is supplied.

Further, the upper mold 2 is provided with a heater 6 for preheating the upper mold 2 to a predetermined temperature. Similarly, the lower mold 3 is provided with a heater 7 for preheating the lower mold 3 to a predetermined temperature.

<Manufacturing method of fiber reinforced plastic molded products>
As shown in FIG. 2, the manufacturing method according to the present embodiment is roughly divided into a first step S1 as a preparatory step and a second step S2 to a fifth step S5 as a pressing step. ..

Of these, the first step S1 is a step of preparing the cloth-like body 11 and the resin sheet 12 which are made of the resin composition 11b having a melting point lower than that of the resin sheet 12 as the resin composition 11b. ..

On the other hand, in the second step S2 to the fifth step S5, the resin sheet 12 is laminated on the surface layer side of the cloth-like body 11, and the melting point of the resin composition 11b used for the cloth-like body 11 (first melting point T1) is determined. This is a step of performing press molding while being heated to a temperature (press temperature T3) between the melting point of the resin sheet 12 (second melting point T2) and the melting point (second melting point T2).

Hereinafter, the first step S1 to the fifth step S5 will be described in order.

(First step)
The first step S1 is a step of preparing a cloth-like body 11 made of the resin composition 11b set to the first melting point T1 and a resin sheet 12 set to the second melting point T2.

The cloth-like body 11 is preferably a non-woven fabric type resin. More preferably, the cloth-like body 11 is a resin obtained by forming a non-woven fabric of carbon fibers as a fiber base material 11a and polypropylene fibers as a resin composition 11b by a papermaking method. The cloth-like body 11 is subjected to the press molding described later to become a fiber-reinforced resin in which the fiber base material 11a is used as a reinforcing fiber and the resin composition 11b is used as a matrix resin.

Here, as the fiber base material 11a, instead of carbon fibers, boron fibers, glass fibers, aramid fibers, hemp fibers, polyethylene fibers, zylon fibers, carbon nanofibers, cellulose nanofibers and the like can be used.

The resin sheet 12 is a matte material made of a resin having a melting point higher than that of the resin composition 11b used for the cloth-like body 11. That is, assuming that the melting point of the resin composition 11b is the first melting point T1 and the melting point of the resin sheet 12 is the second melting point T2.
T1 <T2 ... (1)
The resin composition 11b and the resin sheet 12 may be selected so that the above relationship is satisfied.

Specifically, when polypropylene fiber is selected as the resin composition 11b, its first melting point T1 is about 170 ° C. In this case, as the resin sheet 12, for example, a so-called PET sheet made of polyethylene terephthalate (PET) can be used. When a PET sheet is used as the resin sheet 12, its second melting point T2 is about 260 ° C., and the relationship (1) above is satisfied.

In addition, as the resin sheet 12, polypropylene, polyamide, polyethylene, ABS resin, polycarbonate and the like can also be used, including the case where a resin composition 11b other than polypropylene fiber is used.

(Second step)
The second step S2 is a step of laminating the cloth-like body 11 and the resin sheet 12.

As shown in the left figure of FIG. 3, the laminated body 101 formed by laminating the cloth-like body 11 and the resin sheet 12 is inserted between the upper mold 2 and the lower mold 3 of the manufacturing apparatus 1. Here, the resin sheet 12 forms the surface layer of the fiber-reinforced resin molded product 102. Therefore, as shown in G1 of FIG. 4, the resin sheet 12 is laminated on the surface layer side of the cloth-like body 11.

(Third step)
The third step S3 is a step of press-molding the laminate 101 while being heated to a press temperature T3 between the first melting point T1 and the second melting point T2.

The press temperature T3 is higher than the first melting point T1 and lower than the second melting point T2, and is realized by preheating the upper mold 2 and the lower mold 3, respectively. That is, prior to charging the laminated body 101 into the manufacturing apparatus 1,
T1 <T3 <T2 ... (2)
The upper mold 2 and the lower mold 3 may be preliminarily heated so that the above relationship is satisfied.

The press temperature T3 is preferably a temperature closer to the first melting point T1 which is the melting point of the resin composition 11b (the second melting point T2 and the first melting point T1) than the second melting point T2 which is the melting point of the resin sheet 12. The temperature on the first melting point T1 side of the second melting point T2) is set with respect to the intermediate value of. That is,
｜ T3-T1 ｜ ＜ ｜ T3-T2 ｜… (3)
It is preferable to preheat the upper mold 2 and the lower mold 3 so that the above relationship is satisfied.

The press temperature T3 is more preferably set to a temperature closer to an intermediate value between the first melting point T1 and the second melting point T2 than the first melting point T1. That is,
| T3-T1 |> | T3- (T1 + T2) / 2 | ... (4)
It is more preferable to preheat the upper mold 2 and the lower mold 3 so that the above relationship is satisfied.

Specifically, when polypropylene fiber (first melting point: about 170 ° C.) is used as the resin composition 11b and PET sheet (second melting point: about 260 ° C.) is used as the resin sheet 12, (2) to (4). ), The press temperature T3 may be set to, for example, 200 ° C.

The surface pressure during press molding is preferably set to 3 MPa or more and 4 MPa or less. After setting the surface pressure, by pressing the laminated body 101 in a state of being further heated to the above-mentioned press temperature T3, as shown in the right figure of FIG. 3, between the upper mold 2 and the lower mold 3. The fiber reinforced resin molded product 102 is molded.

Here, when press molding is performed using the conventional method, the fiber base materials 11a in the cloth-like body 11 interfere with each other in the pressing step, and as shown in G2 of FIG. 4, the compression direction by the press is different. There is a problem that the repulsive force A1 is generated in the opposite direction, and the fiber base material 11a can penetrate the resin sheet 12 due to the repulsive force A1. As shown in G3 of FIG. 4, the fiber-reinforced resin molded product 102'obtained by the conventional method has the fiber base material 11a penetrating from the surface of the resin sheet 12, which is inconvenient from the viewpoint of surface smoothness. ..

On the other hand, the fiber-reinforced resin molded product 102 in which the penetration of the fiber base material 11a is suppressed by performing press molding while satisfying at least the relationship (2) as in the method according to the present embodiment (method of the present application). Can be molded.

Specifically, when press molding is performed using the method of the present application, the resin composition 11b in the cloth-like body 11 is melted and impregnated in the same manner as in the case of using the conventional method. As a result, the cloth-like body 11 forms a fiber-reinforced resin having the resin composition 11b as the central layer. At that time, the resin sheet 12 is pressed by the upper mold 2 while pressing the fiber base material 11a in the cloth-like body 11 in a softened state even if it does not reach the melting point. As a result, as shown in G4 of FIG. 4, the resin sheet 12 forms a surface layer of the fiber reinforced resin without penetrating the fiber base material 11a from the surface. In this way, the fiber-reinforced resin molded product 102 composed of the fiber-reinforced resin formed by the cloth-like body 11 and the surface layer formed by the resin sheet 12 is molded.

As described above, since the fiber-reinforced resin molded product 102 can be manufactured without penetrating the fiber base material 11a from the surface, it is possible to realize a molded product having excellent surface smoothness. In addition, this manufacturing method does not require a polishing repair step using a surfacer, and is therefore excellent in productivity.

Further, in the third step S3 according to the present embodiment, the cloth-like body 11, particularly the resin layer (hereinafter referred to as “first resin layer”) L1 made of the resin composition 11b, and the resin layer (hereinafter referred to as “first resin layer”) L1 and the resin sheet 12 (hereinafter referred to as “first resin layer”). , "Second resin layer") and L2, press molding is performed so that a part of the fiber base material 11a penetrates into the boundary portion. The invasion of the fiber base material 11a into the boundary portion is at least the relationship (2), preferably the relationship (2) to (3), and more preferably (2) among the relationships (2) to (4). It is realized by satisfying all of (4).

By invading a part of the fiber base material 11a into the boundary between the first resin layer L1 and the second resin layer L2, the anchor effect is exhibited, and the space between the first resin layer L1 and the second resin layer L2 is exhibited. The joint strength can be improved. Further, by keeping the resin sheet 12 invading not the entire area but the boundary portion, it is also advantageous in suppressing the penetration of the fiber base material 11a.

(4th step)
The fourth step S4 is a step of cooling the fiber-reinforced resin molded product 102 while maintaining the state in which the fiber-reinforced resin molded product 102 is pressed by the upper mold 2 and the lower mold 3. The fourth step S4 is executed by passing a liquid refrigerant through the refrigerant passage 8 of the upper mold 2 and the refrigerant passage 9 of the lower mold 3.

(Fifth step)
The fifth step S5 is a step of raising the upper die 2 of the upper die 2 and the lower die 3 as the press die to remove the press-molded fiber reinforced resin molded product 102. The demolded fiber reinforced resin molded product 102 is carried out from the lower mold 3.

<Example of manufacturing method>
Hereinafter, specific examples will be described with reference to FIG.

As the cloth-like body 11, a resin obtained by converting carbon fibers as a fiber base material 11a and polypropylene fibers as a resin composition 11b into a non-woven fabric by a papermaking method was used. As the resin sheet 12, a PET sheet was used. In this case, the first temperature T1 is about 170 ° C. and the second temperature T2 is about 260 ° C. Further, the heating temperature at the time of press molding, that is, the third temperature T3 was set to 200 ° C. This setting satisfies all the relationships (2) to (4). The surface pressure during press molding was set in the range of 3 to 4 MPa.

In this case, as shown in FIG. 5, the cloth-like body 11 and the resin sheet 12 are laminated so that the resin sheet 12 is located on the surface layer side. Then, in the fiber-reinforced resin molded product 102, a part of the fiber base material 11a penetrates into the boundary between the first resin layer L1 made of the cloth-like body 11 and the second resin layer L2 made of the resin sheet 12. It is composed of.

Specifically, although the fiber base material 11a in the cloth-like body 11 partially penetrates into the second resin layer L2 made of the resin sheet 12, it is not exposed to the outside from the second resin layer L2. At least a part of the fiber base material 11a penetrates the boundary line between the first resin layer L1 and the second resin layer L2 (see Bl in FIG. 6).

The boundary portion referred to here refers to a portion of the fiber-reinforced resin molded product 102 that includes the boundary line Bl between the first resin layer L1 and the second resin layer L2 and has a predetermined thickness. The thickness of the boundary portion is set to be at least thinner than the thickness of the second resin layer L2, preferably 50% or less of the thickness of the second resin layer L2, and more preferably 20% or less of the thickness of the second resin layer L2. ..

As described above, the present disclosure is useful for manufacturing outer panel parts of automobiles such as bonnets and fender panels, and has industrial applicability.

1 Manufacturing equipment 11 Cloth-like body 11a Fiber base material 11b Resin composition 12 Resin sheet 101 Laminated body 102 Fiber-reinforced resin molded product L1 First resin layer (resin layer made of cloth-like body)
L2 second resin layer (resin layer made of resin sheet)
S1 1st process (preparation process)
S2 to S5 2nd to 5th steps (pressing process)
T1 first melting point (melting point of resin composition)
T2 2nd melting point (melting point of resin sheet)

Claims (6)

A method for producing a fiber-reinforced resin molded product in which a cloth-like body formed by combining a predetermined resin composition with a fiber base material and a resin sheet having a composition different from that of the resin composition are laminated and press-molded. hand,
A preparatory step for preparing the cloth-like body and the resin sheet using a resin composition having a melting point lower than that of the resin sheet as the resin composition.
The resin sheet is laminated on the surface layer side of the cloth-like body, and is provided with a press step of performing press molding while being heated to a temperature between the melting point of the resin composition and the melting point of the resin sheet. A method for producing a fiber-reinforced resin molded product. In the method for producing a fiber-reinforced resin molded product according to claim 1,
In the pressing step, the intermediate value between the melting point of the resin composition and the melting point of the resin sheet is pressed in a state of being heated to a temperature closer to the melting point of the resin composition than the melting point of the resin sheet. A method for producing a fiber-reinforced resin molded product, which comprises molding. In the method for producing a fiber-reinforced resin molded product according to claim 2.
The press step is a fiber characterized in that the press molding is performed in a state of being heated to a temperature close to an intermediate value between the melting point of the resin composition and the melting point of the resin sheet as compared with the melting point of the resin composition. A method for manufacturing a reinforced resin molded product. In the method for producing a fiber-reinforced resin molded product according to any one of claims 1 to 3.
The press step is characterized in that the fiber is press-molded so that a part of the fiber base material penetrates into the boundary between the resin layer made of the cloth-like body and the resin layer made of the resin sheet. A method for manufacturing a reinforced resin molded product. A fiber-reinforced resin molded product obtained by laminating a cloth-like body formed by combining a predetermined resin composition with a fiber base material and a resin sheet having a composition different from that of the resin composition.
The melting point of the resin composition is lower than that of the resin sheet.
The cloth-like body and the resin sheet are laminated so that the resin sheet is located on the surface layer side, and the cloth-like body and the resin sheet are laminated at a boundary portion between the resin layer made of the cloth-like body and the resin layer made of the resin sheet. A fiber-reinforced resin molded product characterized in that a part of the fiber base material is configured to penetrate. A fiber-reinforced resin molded product according to claim 5, wherein the fiber-reinforced resin molded product is an outer panel component of an automobile.

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