Manufacturing method of a resin composite board and manufacturing method of a three-dimensional article

Abstract

A method of manufacturing a resin composite board (10) by heating a plurality of fiber-reinforced thermoplastic resin sheets (12) laid on a plane under pressure and thereby integrating the fiber-reinforced thermoplastic resin sheets (12) into a resin composite board (10), each of the fiber-reinforced thermoplastic resin sheets (12) containing fibers (F) arranged in one direction, wherein: a connecting surface (30a) between adjacent fiber-reinforced thermoplastic resin sheets (12) is in the form of a curved surface.

Description

STATE OF THE ARTField of invention:

[0001] The present invention relates to a manufacturing method of a resin composite board by heating a plurality of fiber-reinforced thermoplastic resin sheets laid on a plane under pressure and thereby integrating the resin sheets, and a method for manufacturing a three-dimensional object. Description of the state of the art:

[0002] JP 2013 - 221 114 A discloses a technique for producing a resin sheet by stacking a plurality of pieces of carbon fiber composite resin materials, each of which has a uniform thickness.

[0003] DE 101 53 875 A1 is directed to forming components from a fiber-resin compound, wherein the component geometry and structure are optimized for the forces occurring during use and wherein the component is constructed from several layers that are either glued or thermally welded together.

[0004] US 2016 / 0 167 762 A1 aims at a method for producing large-area composite structures in which the modules are joined at their respective edges using a flame joint.

[0005] US 5 601 676 A discloses a method for joining and repairing composite materials, which comprises providing complementary matching and interlocking surface configurations of the composite materials and the material to which the composite materials are to be joined, interlocking the two materials at their joining line, and then adhering at least one patch to both surfaces of the interlocking material combination, thereby securing the composite material to the other material.

[0006] US 5,474,635 A discloses a method for joining adjacent, non-coplanar fiber-reinforced composite structures, in which a plurality of serrations are machined into an edge of a consolidated first fiber-reinforced composite structure such that reinforcing fibers extend from a main body of the first fiber-reinforced composite structure into the serrations. One or more reinforcing fiber layers are then placed around the serrations to form an unconsolidated second structure together with a matrix precursor. Heat and pressure are applied to the unconsolidated second structure and the serrations to consolidate the second structure into a fiber-reinforced composite structure.

[0007] US 2017 / 0 057 666 A1 discloses a method and apparatus for layer bending, whereby a desired thickness and stiffness distribution is obtained for a composite structure. A composite material may contain reinforcing fibers bound in a polymer resin matrix, whereby thermoplastic or thermosetting resins may be used. SUMMARY OF THE INVENTION

[0008] By reducing the unit thickness of carbon fiber composite resin materials, it is possible to finely control the thickness of the resin sheet. Therefore, it is possible to obtain the resin sheet with a desired thickness. However, a problem arises in that the manufacturing cost increases because the number of pieces of carbon fiber composite resin materials to be stacked increases and, accordingly, the number of processes for stacking the carbon fiber composite resin materials increases.

[0009] On the other hand, by thickening the unit thickness of the carbon fiber composite resin materials to be used, it is possible to reduce the number of pieces of carbon fiber composite resin materials to be used. However, another problem arises in that it is impossible to fine-tune the thickness of the resin sheet.

[0010] The present invention was conceived to solve the aforementioned problems, and it is an object of the present invention to provide a manufacturing method for a resin composite sheet that can reduce the number of fiber-reinforced thermoplastic resin sheets to be stacked while finely controlling the thickness of the resin composite sheet. It is also an object of the invention to provide a manufacturing method for a three-dimensional object.This object is achieved by the manufacturing method according to the invention according to claim 2 and the manufacturing method according to the invention according to claim 1, according to which the production of a resin composite plate is carried out by heating a plurality of fiber-reinforced thermoplastic resin sheets under pressure, which are laid on a plane, and by integrating the fiber-reinforced thermoplastic resin sheets into a resin composite plate, wherein each of the fiber-reinforced thermoplastic resin sheets contains fibers arranged in one direction, wherein a connecting surface between adjacent fiber-reinforced thermoplastic resin sheets is in the form of a curved surface.

[0011] According to a first example not constituting an embodiment of the present invention, there is provided a resin composite sheet manufacturing method for manufacturing a resin composite sheet by heating under pressure a resin sheet group in which a plurality of fiber-reinforced thermoplastic resin sheets are stacked together, and thereby integrating the resin sheet group into a resin composite sheet, each of the fiber-reinforced thermoplastic resin sheets containing fibers arranged in one direction, the manufacturing method comprising manufacturing the resin composite sheet having a desired thickness by stacking the plurality of fiber-reinforced thermoplastic resin sheets having different thicknesses.

[0012] According to a second example not constituting an embodiment of the present invention, there is provided a manufacturing method of a resin composite sheet for manufacturing a resin composite sheet by heating under pressure a resin sheet group comprising a plurality of fiber-reinforced thermoplastic resin sheets stacked together, and thereby integrating the resin sheet group into a resin composite sheet, each of the fiber-reinforced thermoplastic resin sheets containing unidirectionally arranged fibers, wherein at least one of the plurality of stacked fiber-reinforced thermoplastic resin sheets differs in fiber volume fraction from others of the stacked fiber-reinforced thermoplastic resin sheets.

[0013] According to one aspect of the present invention, there is provided a manufacturing method of a resin composite sheet for manufacturing a resin composite sheet by heating a plurality of fiber-reinforced thermoplastic resin sheets laid on a plane under pressure, and thereby integrating the fiber-reinforced thermoplastic resin sheets into a composite sheet, wherein each of the fiber-reinforced thermoplastic resin sheets contains fibers arranged in one direction, wherein a joint surface between the adjacent fiber-reinforced thermoplastic resin sheets is in the form of a curved surface.

[0014] According to the first example, the number of fiber-reinforced thermoplastic resin sheets to be used can be reduced compared to a case where a resin composite sheet is manufactured by stacking a plurality of fiber-reinforced thermoplastic resin sheets having the same thickness. Accordingly, it is possible to reduce the number of processes for stacking the fiber-reinforced thermoplastic resin sheets and thus reduce the manufacturing cost. Furthermore, it is possible to finely adjust the thickness of the resin composite sheet by stacking the plurality of fiber-reinforced thermoplastic resin sheets of different thicknesses, thus easily manufacturing the resin composite sheet with a desired thickness.

[0015] According to the second example, among the multiple stacked fiber-reinforced thermoplastic resin sheets, some fiber-reinforced thermoplastic resin sheets requiring strength can be made stronger, while the other fiber-reinforced thermoplastic resin sheets requiring relatively little strength can be made weaker. As a result, the manufacturing cost can be reduced.

[0016] According to the aspect of the invention, as compared with the case where the bonding surface is in the form of a plane, it is possible to increase the area of ​​the bonding surface, and therefore it is possible to prevent the resin composite plate from breaking at the bonding surface between the fiber-reinforced thermoplastic resin sheets.

[0017] The above and other objects, features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings in which preferred embodiments of the present invention are shown by way of illustrative examples. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1A is a schematic view for explaining a manufacturing method of a resin composite board according to an example not constituting an embodiment of the present invention, and shows a state in which a plurality of fiber-reinforced thermoplastic resin sheets are stacked; Fig. 1B is a schematic view for explaining the manufacturing method of the resin composite sheet according to the example, and shows a resin composite sheet manufactured by heating a resin sheet group comprising a plurality of fiber-reinforced thermoplastic resin sheets stacked together under pressure; Fig. 2 is a schematic view showing an example in which fiber directions in the resin composite board intersect in the manufacturing method of the resin composite board according to the example; Fig. 3 is a schematic view showing an example in which fiber directions of two fiber-reinforced thermoplastic resin sheets stacked side by side intersect in the manufacturing process of the resin composite board; Fig. 4 is a schematic view for explaining molding by a pressing device; Fig. 5A is a schematic view for explaining a manufacturing process of a resin composite board according to a first example not constituting an embodiment of the present invention, and shows a state in which a plurality of resin sheet groups are laid on a plane; Fig. 5B is a schematic view for explaining the manufacturing method of the resin composite board according to the first example, and shows a resin composite board manufactured by heating the plurality of resin sheet groups laid on a plane under pressure; Fig. 6A is a schematic view showing a state in which a plurality of resin sheet groups having different thicknesses are laid on a plane in the manufacturing method of the resin composite board according to the first example; Fig. 6B is a schematic view showing a resin composite plate manufactured by heating under pressure the plurality of resin sheet groups having different thicknesses laid on the plane in the manufacturing method of the resin composite plate according to the first example; Fig. 7 is a schematic view showing an example in which the numbers of fiber-reinforced thermoplastic resin sheets in the resin sheet groups are different in the manufacturing method of the resin composite board according to the first example; Fig. 8 is a schematic view for explaining a manufacturing method of a resin composite board according to an embodiment of the invention, wherein bonding surfaces between resin sheet groups are in the form of curved lines; Fig. 9 is a schematic view for explaining the manufacturing method of the resin composite board according to a second example not being an embodiment of the present invention, wherein bonding surfaces between resin sheet groups are in the form of a plurality of straight lines; and Fig. 10 is a schematic view for explaining the manufacturing method of the resin composite board according to the second example not according to the invention, and shows an example in which each of the resin sheet groups has a regular hexagon. DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, a preferred embodiment and modifications of a manufacturing method of a resin composite board according to the present invention will be described in detail with reference to the accompanying drawings.

[0019] In a manufacturing method of a resin composite sheet 10, a resin composite sheet 10 is manufactured by stacking a plurality of fiber-reinforced thermoplastic resin sheets 12 and then heating a resin sheet group 14 in which a plurality of fiber-reinforced thermoplastic resin sheets 12 are stacked together under pressure to thereby integrate the plurality of resin sheets 12 of the resin sheet group 14.

[0020] Fig. 1A and Fig. 1B are schematic views for explaining the manufacturing process of the resin composite board 10. Fig. 1A shows a state in which the plurality of fiber-reinforced thermoplastic resin sheets 12 are stacked. Fig. 1B shows a resin composite sheet 10 manufactured by heating the resin sheet group 14 in which the plurality of fiber-reinforced thermoplastic resin sheets 12 are stacked together under pressure.

[0021] Each of the fiber-reinforced thermoplastic resin sheets 12 is a sheet made of thermoplastic resin containing fibers F (for example, fibers such as carbon fibers, glass fibers, or the like). The fibers F of the fiber-reinforced thermoplastic resin sheet 12 are arranged in one direction (see Fig. 2 and Fig. 3).

[0022] The resin sheet group 14 is heated under pressure by using an upper die and a lower die (not shown). Further, the produced resin composite sheet 10 is compression-molded into a molded article by a pressing device PA having compression dies (upper die D1 and lower die D2) (see Fig. 4). That is, the upper die D1 and the lower die D2 sandwich or clamp the resin composite sheet 10 and press the resin composite sheet 10 to form a molded article of three-dimensional shape. Incidentally, the production of the resin composite sheet 10 can be carried out by heating the resin sheet group 14 under pressure and producing the molded article by compression molding by a single press device PA. For example, the resin sheet group 14 can be heated under pressure and compression molded simultaneously.

[0023] In the manufacturing method, the resin composite plate 10 having a desired thickness is manufactured by heating the resin sheet group 14 containing a plurality of fiber-reinforced thermoplastic resin sheets 12 having different thicknesses stacked together under pressure.

[0024] Fig. 1A and Fig. 1B show an example in which three fiber-reinforced thermoplastic resin sheets 12 are stacked to facilitate understanding of the description. In Fig. 1A and Fig. 1B, the fiber-reinforced thermoplastic resin sheets 12 of the upper layer and the lower layer have the same thickness (e.g., 0.05 mm), while the fiber-reinforced thermoplastic resin sheet 12 of the intermediate layer (middle layer) has the greatest thickness (e.g., 0.5 mm). Incidentally, the fiber-reinforced thermoplastic resin sheets 12 of the upper layer and the lower layer may have different thicknesses.

[0025] In this way, since the resin composite sheet 10 is manufactured by stacking the plurality of fiber-reinforced thermoplastic resin sheets 12 having different thicknesses, the number of fiber-reinforced thermoplastic resin sheets 12 to be used can be reduced compared to a case where the resin composite sheet 10 is manufactured by stacking a plurality of fiber-reinforced thermoplastic resin sheets 12 having the same thickness. Accordingly, the number of processes for stacking the fiber-reinforced thermoplastic resin sheets 12 is reduced, and therefore, the manufacturing cost can be reduced. Furthermore, the thickness of the resin composite sheet 10 can be finely controlled as a result of stacking the plurality of fiber-reinforced thermoplastic resin sheets 12 having different thicknesses, and therefore, it is possible to easily manufacture the resin composite sheet 10 having a desired thickness.

[0026] According to the prior art method, for example, in a case where a resin composite sheet 10 with a thickness of 0.6 mm is manufactured by using a plurality of fiber-reinforced thermoplastic resin sheets 12 each having a thickness of 0.1 mm, it is necessary to stack six sheets of the fiber-reinforced thermoplastic resin sheets 12. As a result, when adjusting the thickness of the resin composite sheet 10, the adjustment can only be performed in units of 0.1 mm. On the other hand, in order to prioritize the fine adjustment of the fiber-reinforced thermoplastic resin sheets 12 in a case where the resin composite sheet 10 with a thickness of 0.6 mm is manufactured by using the fiber-reinforced thermoplastic resin sheets 12 each having a thickness of 0.05 mm, the fine adjustment of the thickness of the resin composite sheet 10 can be performed in units of 0.05 mm.However, it is necessary to stack not less than twelve sheets of the fiber-reinforced thermoplastic resin sheets 12.

[0027] Further, in the manufacturing method according to an example not constituting an embodiment of the invention, the resin composite plate 10 of a desired thickness can be manufactured by stacking the plurality of fiber-reinforced thermoplastic resin sheets 12 having different thicknesses such that the fiber directions (the directions of the fibers F) of the resin sheet group 14 cross each other (preferably perpendicularly), as shown in Fig. 2. As a result, it is possible to reduce the directionality of the resin composite sheet 10, and therefore, the resin composite sheet 10 exhibits improved strength.

[0028] Further, the resin composite plate 10 of a desired thickness can be manufactured by stacking the plurality of fiber-reinforced thermoplastic resin sheets 12 having different thicknesses so that the directions of the fibers F of two adjacently stacked fiber-reinforced thermoplastic resin sheets 12 cross each other, as shown in Fig. 3. As a result, it is possible to eliminate the directionality of the resin composite board 10, and hence, the strength of the resin composite board 10 is further improved.

[0029] As the fiber volume fraction (Vf) increases, the fiber-reinforced thermoplastic resin sheets 12 become stronger, but more expensive. To suppress such a cost increase, at least one of the stacked plurality of fiber-reinforced thermoplastic resin sheets 12 of the resin sheet group 14 may differ in fiber volume fraction from other fiber-reinforced thermoplastic resin sheets 12. For example, the fiber volume fraction of the fiber-reinforced thermoplastic resin sheet 12 of the intermediate layer may be made larger than the fiber volume fraction of the fiber-reinforced thermoplastic resin sheets 12 of the upper layer and the lower layer.With this structure, among the plurality of stacked fiber-reinforced thermoplastic resin sheets 12, some fiber-reinforced thermoplastic resin sheets 12 requiring strength can be made stronger, while other fiber-reinforced thermoplastic resin sheets 12 relatively not requiring strength can be made weaker.

[0030] As a result, production costs can be reduced. [Modifications]

[0031] The example described above can be modified as follows. <Erste Modifikation>

[0032] Fig. 5A and Fig. 5B are schematic views for explaining a manufacturing method of the resin composite board 10 according to a first modification. Fig. 5A shows a state in which a plurality of resin sheet groups 14 are laid on one plane. Fig. Fig. 5B shows a resin composite plate 10 which is manufactured by heating the plurality of resin sheet groups 14 laid on the plane under pressure. Although the plurality of resin sheet groups 14 are arranged at predetermined intervals in Fig. 5A, they are actually arranged on the plane without any space. Otherwise, the same components as those in the aforementioned example are given the same reference numerals, and a description will be given only with respect to components different from those in the aforementioned example.

[0033] Furthermore, reference numeral 30 denotes connecting parts between the resin sheet groups 14 (the fiber-reinforced thermoplastic resin sheets 12) that are laid on the plane. Reference numeral 30a denotes connecting surfaces (abutting surfaces of the connecting parts).

[0034] In the manufacturing method of the resin composite board 10 in the first modification, a resin composite board 10 is manufactured by laying or arranging the plurality of resin sheet groups 14 densely without any gap between them (see Fig. 5A) and then heating the several resin sheet groups 14 placed tightly on the plane under pressure to thereby integrate the resin sheet groups 14 into the one resin composite plate (see Fig. 5B). As a result, it is possible to easily manufacture the resin composite plate 10 suitable for the size and shape of a molded article to be formed by pressing.

[0035] As the thickness and fiber content (the fiber F content) of the entire resin sheet group 14 increase, the resin sheet group 14 increases in strength but increases in cost. To suppress such cost increase, at least one of the plurality of resin sheet groups 14 laid on the plane may differ from the other resin sheet groups 14 in at least one of thickness and fiber F content. By partially changing the thickness or fiber F content of the resin sheet groups 14 as above, it is possible to increase the strength of the resin sheet group 14 requiring strength and reduce the strength of the resin sheet group 14 not requiring strength. As a result, the manufacturing cost can be reduced.

[0036] In this case, at least one of the thickness and the fiber F content of the resin sheet groups 14 can be changed depending on a portion of a molded article to be compression-molded from the resin composite sheet 10. Therefore, of the molded article obtained by compression molding, a portion requiring strength can be made stronger, while a portion not requiring strength can be made weaker. Accordingly, the manufacturing cost can be reduced. Furthermore, it is possible to easily manufacture the resin composite sheet 10 suitable for a molded article to be obtained by compression molding.

[0037] By the way, Fig. 6A is a schematic view showing a state in which a plurality of resin sheet groups 14 having different thicknesses are laid on a plane, and Fig. Fig. 6B is a schematic view showing a resin composite plate 10 produced by heating the plurality of resin sheet groups 14 of different thickness laid on the plane under pressure. Although the plurality of resin sheet groups 14 are laid at predetermined intervals in Fig. 6A, they are actually placed or arranged on the plate without any space.

[0038] Furthermore, in the manufacturing method of the first modification, at least one of the plurality of resin sheet groups 14 laid on the plane may differ from the other resin sheet groups 14 in the number of stacked fiber-reinforced thermoplastic resin sheets 12, the thickness, the fiber content (F), or the fiber volume fraction. By partially changing the thickness, the fiber content (F), the fiber volume fraction, or the number of fiber-reinforced thermoplastic resin sheets 12 constituting the resin sheet group 14, it is possible to increase the strength of some of the resin sheet groups 14 that require strength and weaken the strength of the other resin sheet groups 14 that do not require strength. Accordingly, the manufacturing cost can be reduced.

[0039] In this case, the thickness, the content of fiber F, the fiber volume fraction, or the number of the fiber-reinforced thermoplastic resin sheets 12 of the resin sheet group 14 may be changed depending on a part of a molded article to be molded from the resin composite sheet 10.

[0040] Furthermore, Fig. 7 is a schematic view showing an example in which the numbers of the fiber-reinforced thermoplastic resin sheets 12 of the resin sheet groups 14 are different from each other. As in Fig. 7, the number of fiber-reinforced thermoplastic resin sheets 12 of one of the resin sheet groups 14 is three, while the number of fiber-reinforced thermoplastic resin sheets 12 of the other resin sheet group 14 is five.

[0041] To cause the thickness, the fiber F content, or the fiber volume fraction of the fiber-reinforced thermoplastic resin sheets 12 of the one resin sheet group 14 to be different from those of another resin sheet group 14 means that the thickness, the fiber F content, or the fiber volume fraction of at least one of the plurality of fiber-reinforced thermoplastic resin sheets 12 of the one resin sheet group 14 is different from the thickness, the fiber F content, or the fiber volume fraction of each of the plurality of fiber-reinforced thermoplastic resin sheets 12 of the other resin sheet group 14.For example, a case is included in which the three fiber-reinforced thermoplastic resin sheets 12 constituting one resin sheet group 14 have respective thicknesses of 0.05 mm, 0.06 mm, and 0.5 mm, while the three fiber-reinforced thermoplastic resin sheets 12 constituting another resin sheet group 14 have respective thicknesses of 0.05 mm (two sheets) and 0.5 mm (one sheet). <Zweite Modifikation>

[0042] In the aforementioned first modification, the rectangular resin sheet groups 14 (each containing the fiber-reinforced thermoplastic resin sheets 12) are laid on the plane. In this structure, the connecting surfaces 30a between the resin sheet groups 14 are each in the form of a plane (a flat or straight surface), and the plurality of connecting surfaces 30a are adjacent to each other and arranged linearly (see Fig. 5A and Fig. 5B). Therefore, the resin composite panel 10 easily breaks at the connecting parts 30 between the resin sheet groups 14.

[0043] To address this, in one embodiment of the invention, the bonding surfaces 30a between adjacently arranged resin sheets 12 have the shape of a curved surface.

[0044] Fig. 8 shows an embodiment in which terminal surfaces 30a between the resin trace groups 14 are each in the form of a curved line. Fig. 9 shows another example in which the connecting surfaces 30a between the resin track groups 14 are all in the form of several straight lines.

[0045] With this structure, it is possible to increase the area of ​​the connecting surface 30a compared to the case where the connecting surfaces 30a are in the form of a plane, and therefore it is possible to prevent the resin composite plate 10 from breaking at the connecting parts 30 between the resin sheet groups 14.

[0046] Furthermore, the resin track groups 14 can have a polygonal shape. Fig. Fig. 10 is a schematic view showing an example not according to the invention in which the resin trace groups 14 are each formed in a regular hexagonal shape. Although each of the connecting surfaces 30a between the resin trace groups 14 is in the form of a plane, in the example shown in Fig. In the example shown in FIG. 10, a plurality of terminal surfaces 30a are arranged in different directions without being linearly adjacent to one another. Therefore, it is possible to prevent the resin composite sheet 10 from breaking at the terminal portions 30 between the resin sheet groups 14. By forming the resin sheet groups 14 in the polygonal shape as above, it is possible to prevent the resin composite sheet 10 from breaking at the terminal portions 30 between the resin sheet groups 14, which would otherwise be caused by stresses applied in different directions. Furthermore, it is possible to reduce the amount of material and the weight while maintaining the strength. <Dritte Modifikation>

[0047] In a case where at least one of the plurality of fiber-reinforced thermoplastic resin sheets 12 constituting a resin sheet group 14 is manufactured to differ in fiber volume fraction from the other fiber-reinforced thermoplastic resin sheets 12 (an aspect in the above-described example), the plurality of fiber-reinforced thermoplastic resin sheets 12 of the resin sheet group 14 may have the same thickness. Even in this case, some of the fiber-reinforced thermoplastic resin sheets 12 requiring strength can be made stronger, while the other fiber-reinforced thermoplastic resin sheets 12 requiring relatively little strength can be made weaker, and therefore, the manufacturing cost can be reduced. <Vierte Modifikation>

[0048] In a case where a piece of resin composite board 10 is manufactured with a plurality of resin sheet groups 14 arranged on a plane, and the connecting surfaces 30a between the adjacently arranged resin sheet groups 14 are in the form of a curved surface, a plurality of planes, or a combination of curved surfaces and planes (an aspect described in the second modification), the plurality of fiber-reinforced thermoplastic resin sheets 12 constituting the resin sheet groups 14 may have the same thickness. Furthermore, even in the case where the resin sheet groups 14 are each formed in a polygonal shape, the plurality of fiber-reinforced thermoplastic resin sheets 12 constituting the resin sheet groups 14 may have the same thickness.Even in these cases, it is possible to increase the area of ​​the connecting surfaces 30a, and therefore it is possible to prevent the resin composite board 10 from breaking at the connecting parts 30 between the resin sheet groups 14.

[0049] According to the present invention, a resin composite sheet 10 can be manufactured by laying a plurality of fiber-reinforced thermoplastic resin sheets 12 on a plane and then heating the plurality of fiber-reinforced thermoplastic resin sheets 12 under pressure. In this case, the connecting portions 30a between the adjacently laid fiber-reinforced thermoplastic resin sheets 12 may be in the form of a curved surface. Further, the fiber-reinforced thermoplastic resin sheets 12 may each be formed in a polygonal shape (for example, a regular hexagon). Even in this case, it is possible to increase the area of ​​the connecting surfaces 30a, and therefore, it is possible to prevent the resin composite sheet 10 from cracking at the connecting portions 30 between the fiber-reinforced thermoplastic resin sheets 12. <Fünfte Modifikation>

[0050] In a fifth modification, a three-dimensional object can be formed by stacking a plurality of manufactured resin composite sheets 10 and then heating the plurality of stacked resin composite sheets 10, wherein the sheets 10 are sandwiched between dies (upper die D1 and lower die D2) of the type shown in Fig. 4 shown pressing device PA can be sandwiched or clamped. <Sechste Modifikation>

[0051] There may be provided an aspect in which the above first to fifth modifications are arbitrarily combined. [Technical concepts]

[0052] The following is a description concerning technical concepts that can be grasped from the above examples and the first to sixth modifications. <Erstes technisches Konzept>

[0053] In a manufacturing method of a resin composite sheet (10) for manufacturing a resin composite sheet (10) by heating a resin sheet group (14) having a plurality of stacked fiber-reinforced thermoplastic resin sheets (12) under pressure and thereby integrating the resin sheet group into a resin composite sheet, wherein the fiber-reinforced thermoplastic resin sheets have each fiber (F) arranged in one direction, the resin composite sheet (10) having a desired thickness is manufactured by stacking the plurality of fiber-reinforced thermoplastic resin sheets (12) having different thicknesses.

[0054] With this configuration, the number of fiber-reinforced thermoplastic resin sheets (12) to be used can be reduced compared to a case where a resin composite sheet (10) is manufactured by stacking a plurality of fiber-reinforced thermoplastic resin sheets (12) having the same thickness. Accordingly, the number of processes for stacking the fiber-reinforced thermoplastic resin sheets (12) is reduced, and therefore, it is possible to reduce the manufacturing cost. Furthermore, the thickness of the resin composite sheet (10) can be finely controlled as a result of stacking the plurality of fiber-reinforced thermoplastic resin sheets (12) having different thicknesses, and therefore, it is possible to easily manufacture the composite resin sheet (10) having a desired thickness.

[0055] The resin composite sheet (10) with a desired thickness can be manufactured by stacking the plurality of fiber-reinforced thermoplastic resin sheets (12) of different thicknesses such that the fiber directions of the fiber-reinforced thermoplastic resin sheets intersect. As a result, it is possible to reduce the directionality in the thickness of the resin composite sheet (10), and thus, the strength of the resin composite sheet (10) is improved.

[0056] The resin composite sheet (10) with a desired thickness can be manufactured by stacking the plurality of fiber-reinforced thermoplastic resin sheets (12) of different thicknesses such that the fiber directions of two adjacently stacked fiber-reinforced thermoplastic resin sheets (12) intersect. As a result, it is possible to eliminate the directionality in the thickness of the resin composite sheet (10), and therefore, the strength of the resin composite sheet (10) is further improved.

[0057] At least one of the plurality of fiber-reinforced thermoplastic resin sheets (12) may differ in fiber volume fraction from others of the stacked fiber-reinforced thermoplastic resin sheets (12). With this configuration, among the plurality of stacked fiber-reinforced thermoplastic resin sheets (12), some fiber-reinforced thermoplastic resin sheets (12) requiring strength can be made stronger, while the other fiber-reinforced thermoplastic resin sheets (12) requiring relatively little strength can be made weaker.

[0058] As a result, production costs can be reduced.

[0059] The resin composite sheet (10) can be produced by heating a plurality of resin sheet groups (14) placed on a plane under pressure and integrating the resin sheet groups into a resin composite sheet, wherein, in each of the resin sheet groups, the plurality of fiber-reinforced thermoplastic resin sheets (12) are stacked together, and wherein the fiber-reinforced thermoplastic resin sheets have different thicknesses. As a result, it is possible to easily produce a resin composite sheet (10) suitable for the size and shape of a molded article to be obtained by compression molding.

[0060] At least one of the plurality of resin sheet groups (14) laid on the plane may differ from the other resin sheet groups (14) in at least one of thickness and fiber content (F). By partially changing the thickness or fiber content (F) of the resin sheet groups (14) as above, it is possible to increase the strength of one resin sheet group (14) that requires strength and to weaken the strength of another resin sheet group (14) that does not require strength. Accordingly, manufacturing costs can be reduced.

[0061] At least one of the thickness and fiber content (F) of the resin sheet groups (14) can be changed depending on a part of an article to be molded from the resin composite sheet (10). Therefore, of a molded article to be molded by pressing, a part requiring strength can be made stronger, while another part not requiring strength can be made weaker. Accordingly, manufacturing costs can be reduced. Furthermore, it is possible to easily manufacture the resin composite sheet (10) suitable for a molded article to be molded by pressing.

[0062] At least one of the plurality of resin sheet groups (14) laid on the plane may differ from the other resin sheet groups (14) in the number of stacked fiber-reinforced thermoplastic resin sheets (12), the thickness, the fiber content (F), or the fiber volume fraction. Therefore, by partially changing the number of fiber-reinforced thermoplastic resin sheets (12) constituting the resin sheet groups (14), the thickness, the fiber content (F), or the fiber volume fraction, it is possible to increase the strength of a resin sheet group (14) requiring strength and weaken the strength of another resin sheet group (14) not requiring strength. Accordingly, the manufacturing cost can be reduced.

[0063] The number of fiber-reinforced thermoplastic resin sheets (12) of the resin sheet groups (14), the thickness, the fiber content (F), or the fiber volume fraction can be changed depending on a part of a molded article to be formed from the resin composite sheet (10). Therefore, of the molded article to be molded by compression molding, a part requiring strength can be made stronger, while a part not requiring strength can be made weaker. Accordingly, the manufacturing cost can be reduced. Furthermore, it is possible to easily manufacture the resin composite sheet (10) suitable for a molded article to be molded by compression molding.

[0064] A connecting surface (30a) between the adjacent resin sheet groups (14) can be in the form of a curved surface, a plurality of planes, or a combination of a curved surface and a plane. With this structure, it is possible to increase the area of ​​the connecting surface (30a) compared to a case where the connecting surface (30a) is in the form of a plane, and therefore it is possible to prevent the resin composite board (10) from breaking at the connecting part (30) between the resin sheet groups (14).

[0065] The resin sheet groups (14) can each have a polygonal shape. With this structure, it is possible to prevent breakage of the resin composite panel (10) at the connecting part (30) between the resin sheet groups (14) to which load is applied in different directions. Furthermore, it is possible to reduce the amount of material and weight while maintaining strength.

[0066] Incidentally, a three-dimensional molded article can be manufactured by heating one or more prepared resin composite sheets (10) under pressure, wherein the one or more resin composite sheets (10) are sandwiched or clamped between the molds. <Zweites technisches Konzept>

[0067] In a manufacturing method of a resin composite sheet (10) for manufacturing a resin composite sheet (10) by heating a resin sheet group (14) comprising a plurality of fiber-reinforced thermoplastic resin sheets (12) stacked together under pressure, and thereby integrating the resin sheet group into a resin composite sheet, wherein each of the fiber-reinforced thermoplastic resin sheets has fibers (F) arranged in one direction, at least one of the plurality of stacked fiber-reinforced thermoplastic resin sheets (12) differs in fiber volume fraction from the other of the stacked fiber-reinforced thermoplastic resin sheets (12).

[0068] With this configuration, among the multiple stacked fiber-reinforced thermoplastic resin sheets (12), some fiber-reinforced thermoplastic resin sheets (12) requiring strength can be made stronger, while the other fiber-reinforced thermoplastic resin sheets (12) requiring relatively little strength can be made weaker. As a result, the manufacturing cost can be reduced.

[0069] Incidentally, a molded article of three-dimensional shape can be produced by heating one or more prepared resin composite sheets (10) under pressure, wherein the one or more resin composite sheets (10) are sandwiched or clamped between the molds. <Drittes technisches Konzept>

[0070] In a manufacturing method of a resin composite board (10) for manufacturing a resin composite board (10) by heating a plurality of fiber-reinforced thermoplastic resin sheets (12) laid on a plane under pressure and thereby integrating the fiber-reinforced thermoplastic resin sheets into a resin composite board, wherein each of the fiber-reinforced thermoplastic resin sheets has fibers (F) arranged in one direction, a connecting surface (30a) between the adjacent fiber-reinforced thermoplastic resin sheets (12) is in the form of a curved surface.

[0071] With this structure, compared to a case where the connecting surface (30a) is in the form of a plane, it is possible to increase the area of ​​the connecting surface (30a) and therefore to prevent the resin composite plate (10) from breaking at the connecting part (30) between the fiber-reinforced thermoplastic resin sheets (12).

[0072] Incidentally, a three-dimensional molded article can be manufactured by heating one or more prepared resin composite sheets (10) stacked together, wherein the one or more resin composite sheets (10) are sandwiched or clamped between the molds.

Claims

[1] A method of manufacturing a resin composite board (10) by heating a plurality of fiber-reinforced thermoplastic resin sheets (12) laid on a plane under pressure and thereby integrating the fiber-reinforced thermoplastic resin sheets (12) into a resin composite board (10), each of the fiber-reinforced thermoplastic resin sheets (12) containing fibers (F) arranged in one direction, wherein: a connecting surface (30a) between adjacent fiber-reinforced thermoplastic resin sheets (12) is in the form of a curved surface. [2] A method of manufacturing a three-dimensional object, comprising: Producing one or more resin composite panels (10) according to the manufacturing method of claim 1; and Heating and pressing the one resin composite plate (10) or several stacked resin composite plates (10) between molds (D1, D2) to form a three-dimensional object.

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