JP2018001600A - Processing method of carbon fiber reinforced plastic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a processing method of carbon fiber reinforced plastic that gives a bright, smooth surface without degrading strength and has an advantage in equipment cost.SOLUTION: A flat plate of carbon fiber reinforced plastic is bored to form holes and then folded while and after softened by heating to form a solid molded article. The solid molded article is set in a molding die with the holes buried leaving a narrow gap. At least one face of an outer face and an inner face of the solid molded article is coated with a resin film 5. The molding die 2 contacting the resin film 5 is heated and closed to compress the resin film 5. The solid molded article of which one face and the surface of the holes are coated with a thermoplastic resin is thus obtained.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method for processing a carbon fiber reinforced plastic using carbon fiber as a reinforcing material.

  The carbon fiber reinforced plastic (CFRP [Carbon Fiber Reinforced Plastic]) is composed of carbon fiber and a matrix resin, and is excellent in mechanical properties, light weight, corrosion resistance, etc., and thus is widely deployed in various applications. As a matrix resin, a thermoplastic resin that has been softened and easily molded when heated has recently attracted attention. The flat plate-like carbon fiber reinforced plastic is molded using the thermoplastic resin, and the molded flat plate-like carbon fiber reinforced plastic is molded into a three-dimensional shape by using a lower mold and an upper mold of a desired shape. There is an RTM (Resin Transfer Molding) method in which pressure is pressed from above and below to form. When flat carbon fiber reinforced plastic is molded into a three-dimensional shape using this RTM method, the flow of synthetic resin impregnated in carbon fiber is minimized, and the arrangement of carbon fiber is changed to reduce strength. It is desirable to avoid incurring. However, because the amount of synthetic resin to be melted is not sufficient, it is not possible to apply a desired amount of pressure to the carbon fiber reinforced plastic, and the surface of the carbon fiber reinforced plastic molded into a three-dimensional shape becomes a glossy smooth surface. Can not do it.

  Therefore, there has been proposed one that increases the ratio of the amount of synthetic resin to carbon fiber by molding carbon fiber reinforced plastic with a small number of carbon fibers of 1000 or less (for example, Patent Document 1).

JP-A-1-163218

  In the configuration of Patent Document 1, although a desired amount of pressure can be applied to the carbon fiber reinforced plastic, there is a problem in that the strength is reduced by the amount of carbon fibers. In addition, when forming a hole in a carbon fiber reinforced plastic molded into a three-dimensional shape, an expensive water jet machining device equipped with a control device that attaches a nozzle to the tip of the robot arm and controls the movement of the robot arm is required. Therefore, it is disadvantageous in terms of equipment cost and difficult to realize.

  Therefore, the present invention has been made in view of such circumstances, and it is possible to make the surface smooth and glossy without incurring a decrease in strength, and to be advantageous in terms of equipment cost. It is an object to provide a processing method.

  In the method for processing a carbon fiber reinforced plastic according to the present invention, holes are formed in a carbon fiber reinforced plastic having a flat plate shape formed by impregnating the carbon fiber with a thermoplastic resin having a melting point lower than that of the carbon fiber. Thereafter, the carbon fiber reinforced plastic is heated and softened at a temperature equal to or higher than the melting point of the thermoplastic resin and lower than the melting point of the carbon fiber. In a state in which a three-dimensional molded product obtained by cooling carbon fiber reinforced plastic is filled in one mold of a mold having a pair of molds that can be freely opened and closed while leaving a small gap in the three-dimensional molded product. And covering at least one of the outer surface and the inner surface of the three-dimensional molded product with a resin film formed of the same material as the thermoplastic resin or a compatible thermoplastic resin. The resin film is set by clamping the pair of molds while heating the mold on the side in contact with the resin film at a temperature higher than the melting point of the resin film and lower than the melting point of the carbon fiber. The molten thermoplastic resin of the resin film covers one surface of the three-dimensional molded product and enters a slight gap between the holes to cover the surface of the holes, and then cools to cool the resin. A three-dimensional molded product in which the one surface and the surface of the hole are coated with a thermoplastic resin is obtained.

  According to the present invention, by first forming a hole in a flat plate-like carbon fiber reinforced plastic, an expensive water jet processing device required when forming a hole in a three-dimensional carbon fiber reinforced plastic is unnecessary. Can be. In order to form a hole in the flat plate-like carbon fiber reinforced plastic, for example, a hole forming process using a simple water jet processing apparatus, a hole forming process using a press process, or a hole forming process using a cutting tool (for example, a drill) may be used. it can. After the formation of the holes, the carbon fiber reinforced plastic is heated and softened at a temperature higher than the melting point of the thermoplastic resin and lower than the melting point of the carbon fiber, and is three-dimensionally molded by bending after being softened. At this time, only the carbon fiber reinforced plastic is bent, and no pressure is applied to the carbon fiber reinforced plastic, so that the arrangement of the carbon fibers is not changed. A state in which a three-dimensional molded product obtained by cooling a three-dimensional molded carbon fiber reinforced plastic is filled in one mold of a mold having a pair of molds with a small gap left between the holes. And at least one of the outer surface and the inner surface of the three-dimensional molded product is a resin film formed of the same material as the thermoplastic resin or a compatible thermoplastic resin (the amount of resin that can be compressed by the mold) Set with the resin film provided. Thereafter, the mold on the side in contact with the resin film is heated at a temperature equal to or higher than the melting point of the resin film and lower than the melting point of the carbon fiber, and the pair of molds are clamped to compress the resin film. The resin film in contact with the mold surface is melted first, and the thermoplastic resin of the melted resin film flows to cover one surface of the three-dimensional molded product and enter a slight gap to cover the surface of the hole. Thereafter, by cooling, it is possible to obtain a three-dimensional molded product in which one surface and the surface of the hole are coated with a thermoplastic resin to become a glossy smooth surface. The other surface of the three-dimensional molded product is covered with a resin film, and the pair of molds are heated and clamped and compressed, so that one side of the three-dimensional molded product and the other surface are both glossy. It can be a smooth surface.

  Further, in the method for processing a carbon fiber reinforced plastic according to the present invention, a hole may be filled in the three-dimensional molded product leaving a slight gap by attaching a nest to the one mold. .

  As described above, by attaching the insert to one of the molds, the hole of the three-dimensional molded product can be filled with a slight gap left. Thereby, while being able to cover reliably with the thermoplastic resin fuse | melted on the surface of a hole, it can prevent that the peripheral part of a hole receives the big pressure from a metal mold | die, and deform | transforms.

  In the method for processing a carbon fiber reinforced plastic according to the present invention, the thermoplastic resin is preferably an epoxy resin.

  As described above, according to the present invention, after the hole is formed in the flat plate-like carbon fiber reinforced plastic, the flat plate-like carbon fiber reinforced plastic is molded into a three-dimensional shape, and the outer surface and the inner surface of the three-dimensional molded product Covering at least one surface with the same material as the thermoplastic resin or a resin film molded with a compatible thermoplastic resin, and compressing with a mold, the surface is glossy without causing a decrease in strength. It is possible to provide a method for processing a carbon fiber reinforced plastic that can be made smooth and that is advantageous in terms of equipment cost.

(A) is a top view of a plane-plate-like carbon fiber reinforced plastic, (b) is a top view which shows the state after forming six holes in the plane-plate-like carbon fiber reinforced plastic of (a). It is a vertical front view of the state which open | released the metal mold | die used for the processing method of carbon fiber reinforced plastics. It is a vertical front view of the state which closed the same metal mold | die and bent the carbon fiber reinforced plastic. It is a vertical front view of the state which open | released the closed metal mold | die of FIG. It is a vertical front view of the metal mold | die which shows the state which covered the carbon fiber reinforced plastic bent to the 2nd recombination insert different from the recombination insert shown in FIG. It is a vertical front view of the metal mold | die which shows the state just before putting a film on the carbon fiber reinforced plastic of FIG. It is a vertical front view of the metal mold | die which shows the state which closed the metal mold | die from the open state of FIG. It is a vertical front view of the metal mold | die which shows the state which open | released the metal mold | die from the closed state of FIG. It is a front view which shows the state which removed the carbon fiber reinforced plastic which covered the recombination nest taken out in FIG. 8 from the recombination nest. (A), (b) shows the first recombination nest, (a) is a front view, (b) is a side view, (c), (d) shows the second recombination nest, (c ) Is a front view, and (d) is a side view.

  2 and 3 show a metal mold 1 used in the method for processing a carbon fiber reinforced plastic of the present invention. The mold 1 includes an upper mold 2 that is a molding mold configured as a female mold having a recess 2a, and a lower mold 3 that is a molding mold configured as a male mold. The upper mold 2 includes a female main body 2A in which the concave portion 2a is formed, and a rectangular horizontal plate 2B provided at the upper end of the main body 2A. The lower mold 3 includes a rectangular horizontal plate 3A serving as a base, a pair of contact portions 3B and 3B that receive the lower end of the main body 2A of the upper mold 2, and a male main body that enters the recess 2a. 3C. Further, the upper die 2 is supported so as to be movable up and down via a support portion (not shown), and is configured to be movable up and down by an actuator (not shown). Therefore, the upper mold 2 is configured to be movable so that the position can be changed between an open position located above the lower mold 3 shown in FIG. 2 and a closed position located below the lower mold 3 shown in FIG. Has been. Although the upper mold 2 is configured to be movable here, the lower mold 3 may be configured to be movable, or both the upper mold 2 and the lower mold 3 may be configured to be movable. Moreover, although comprised in the metal mold | die 1 which moves to an up-down direction, the metal mold | die which moves to a horizontal direction may be sufficient.

  The male main body 3C includes an inverted T-shaped fixing part 31 and a pair of first recombination inserts 32, 32 that are detachably attached to the fixing part 31 (FIG. 10A). , (B) shows one first regenerative nest 32). In addition to the first recombination inserts 32 and 32, a pair of second recombination inserts 33 and 33 are used in exchange (see FIGS. 10 (c) and 10 (d)). To process) carbon fiber reinforced plastic.

  As shown in FIGS. 10A and 10B, each first recombination nest 32 is formed of a substantially rectangular (rectangular) plate-like metal material with a flat surface (outer surface). Each of the second recombination inserts 33 is made of a metal material having the same shape and size as the first recombination inserts 32, as shown in FIGS. 10 (c) and 10 (d), and has a surface. Three protrusions 33A, 33B, and 33C having three different shapes protruding from the (outer surface) are provided. Specifically, as shown in FIG. 10 (c), a square protrusion 33 </ b> A, a circular protrusion 33 </ b> B, and a triangular protrusion 33 </ b> C are formed at predetermined intervals in the longitudinal direction of the second replacement insert 33. doing. The protrusions 33A, 33B, and 33C have the same shape as holes 4A, 4B, and 4C formed in the carbon fiber reinforced plastic (plate material 4) described later, but are formed in the carbon fiber reinforced plastic (plate material 4). It will be changed according to the shape and size of the holes and the number of holes. In addition, the protrusion amount of the protrusions 33A, 33B, and 33C from the surface (outer surface) may be the same as the plate thickness of the carbon fiber reinforced plastic (or may be larger than the plate thickness or vice versa). )doing. In addition, when making the protrusion amount of protrusion part 33A, 33B, 33C larger than the plate | board thickness of carbon fiber reinforced plastic, when the carbon fiber reinforced plastic (plate material 4) mentioned later is covered with the resin film 5, and it clamps, The amount of protrusion is set so that pressure is applied to the carbon fiber reinforced plastic (plate material 4). The sizes (outer dimensions) of the protrusions 33A, 33B, and 33C are set slightly smaller than the inner diameter dimensions of the holes 4A, 4B, and 4C formed in the carbon fiber reinforced plastic (plate material 4).

  Epoxy resins are preferably used as thermoplastic resins used for fiber reinforced plastics, but ABS resins, polypropylene resins, polyamide resins, polyethylene resins, polystyrene resins, polyethylene terephthalate resins, nylon resins, polycarbonate resins, polyacetal resins. , Polybutylene terephthalate resin, polyether ether ketone resin, fluororesin, urethane resin and the like.

  First, the carbon fiber is impregnated with a thermoplastic resin having a melting point lower than that of the carbon fiber to produce a flat plate-like carbon fiber reinforced plastic. For example, a sheet of carbon fiber continuous fiber impregnated with a thermoplastic resin is prepared, press-molded in a soft state by preheating the sheet, and then cooled to below the melting point of the thermoplastic resin to obtain a flat plate shape. Of carbon fiber reinforced plastic. In addition, it is not limited to this manufacturing method, You may manufacture a plane-plate-like carbon fiber reinforced plastic using other shaping | molding methods, such as well-known vacuum forming or vacuum pressure forming.

  A method for processing the manufactured flat plate-like carbon fiber reinforced plastic (hereinafter simply referred to as a plate material) to produce a product will be described. First, a plate material 4 shown in FIG. 1A is prepared, and a hole having a shape required for the plate material 4 is formed using a water jet machining apparatus (not shown). Specifically, as shown in FIG. 1 (b), by opening a square hole 4A, a circular hole 4B, and a triangular hole 4C, which are three differently shaped holes, at the left and right ends of the plate member 4, respectively. , Drill a total of 6 holes. The plate material 4 thus perforated is heated in advance to a temperature equal to or higher than the melting point and lower than the melting point of the carbon fiber to be softened. As shown in FIG. 2, the softened plate member 4 is placed between the upper mold 2 positioned above and the lower mold 3 on which the pair of first replacement inserts 32 and 32 are set (mounted). Set (place). In this state, the upper die 2 is lowered to bend the plate material 4 into a gate shape as shown in FIG. At this time, as shown in the enlarged view of FIG. 3, the size of the space formed by the upper mold 2 and the lower mold 3 (the distance between the recess 2 a of the upper mold 2 and the outer surface 3 a of the lower mold 3) is the plate material 4. Therefore, the pressure from the mold 1 is not applied to the plate material 4. The enlarged view of FIG. 3 shows a state in which a gap S is generated between the plate material 4 and the recess 2a of the upper mold 2. Therefore, the arrangement of the carbon fibers of the plate material 4 is not changed, and the resin extends as the plate material 4 is deformed and bent. In such a state, the front surface and the back surface of the plate member 4 to which pressure from the mold 1 is not applied are surfaces having unevenness that is not smooth. Here, the holes are formed in the plate material 4 using a water jet processing apparatus, but press processing may be used, and holes may be formed by a cutting tool (for example, a drill).

  After the plate material 4 is bent and molded into a three-dimensional shape, the mold 1 is cooled to a temperature lower than the melting point of the resin, and then the upper mold 2 is raised to the upper open position to form a three-dimensional molded product. 4 is taken out (see FIG. 4). In addition, since the shape of this board | plate material 4 is not a state with a sufficient precision, it can finish with a sufficient precision by applying a pressure again mentioned later and performing a secondary process.

  Subsequently, as shown in FIG. 5, the plate material 4 formed into a three-dimensional molded product is set so as to cover the pair of second replacement inserts 33, 33. That is, it sets so that three hole 4A, 4B, 4C of the one side of the board | plate material 4 may enter into protrusion part 33A, 33B, 33C of each 2nd recombination insert 33. FIG. At this time, as described above, the inner diameters of the three holes 4A, 4B, and 4C are set slightly larger than the outer dimensions of the projecting portions 33A, 33B, and 33C, and therefore the three holes 4A, 4B, and 4C are set. The protrusions 33A, 33B, and 33C are inserted in a state where there is slight play.

  Next, the pair of second recombination inserts 33, 33 on which the plate material 4 is set as described above are set on the fixing portion 31 of the lower mold 3 (see FIG. 6). Thereafter, a resin film (in the mold) formed of a thermoplastic resin (here, epoxy resin) of the same material (which may be a resin having good compatibility) as the thermoplastic resin constituting the plate material 4 on the outer surface of the plate material 4 A resin film formed so as to have a compressible amount (thickness) is applied (FIG. 6 shows a state immediately before the application). Subsequently, the upper die 2 is lowered, and the upper die 2 is compressed by lowering (lowering) and compressing while heating the upper die 2 at a temperature higher than the melting point of the resin film 5 and lower than the melting point of the carbon fiber. The resin film 5 that is in contact with the inner surface (recess 2a) of the sheet is melted first, and the molten thermoplastic resin flows to cover one surface (outer surface) of the plate member 4 that is a three-dimensional molded product and slightly. It enters the gap S1 (see the enlarged view of FIG. 7) and covers the surface of the six holes 4A (see the enlarged view of FIG. 5A), and then cools to open the upper mold 2 and the second set The replacement 33, 33 is removed (see FIG. 8). The surface of the plate 4 of the three-dimensional molded product and the surface of the holes 4A are coated with thermoplastic resin by separating the plate 4 as the three-dimensional molded product from the removed second recombination inserts 33, 33, so that the surface is smooth and glossy. A plate material 4 that is a three-dimensional molded product that becomes a surface can be obtained (see FIG. 9). In addition, after obtaining the board | plate material 4 of a three-dimensional molded product, the operation | work which removes the thermoplastic resin adhering to the excess part is performed.

  The good compatibility means that the thermodynamic mutual solubility is good, in other words, it does not separate between the two after curing. Specifically, it is desirable to select resins having the same system. Examples of the resin having good compatibility with the epoxy resin include polyester polyol, acrylic polyol, vinyl resin, acrylic resin, urethane resin, and synthetic rubber.

  As described above, by attaching the second recombination inserts 33, 33 to the lower mold 3 and filling the holes 4A of the plate member 4 which is a three-dimensional molded product with a slight gap left, the holes 4A. Can be covered with a molten thermoplastic resin, and the peripheral edge of the holes 4A can be prevented from being deformed by receiving pressure from the mold 1. Moreover, the same shaping | molding die 2 and 3 can be used by providing the 1st recombination insert 32,32 and the 2nd recombination insert 33,33, for example, respond | corresponds to 2 types of recombination inserts. Compared to the case of preparing two types of lower molds configured in a shape, this is advantageous in terms of cost.

  In addition, the processing method of the carbon fiber reinforced plastic which concerns on this invention is not limited to embodiment, A various change is possible in the range which does not deviate from the summary of this invention.

  In the said embodiment, although only one side (outer surface) of the board | plate material 4 which is a three-dimensional molded product was covered with the resin film 5, only the other surface (inner surface) may be covered with the resin film 5, and each of both surfaces may be covered. May be covered with the resin film 5. When only the other surface (inner surface) is covered with the resin film 5, only the lower die 3 is heated, and when both surfaces are covered with the resin film 5, both the upper die 2 and the lower die 3 are both covered. The mold is heated and molded.

  Moreover, in the said embodiment, although the three-dimensional molded object was shape | molded in the thing which has three surfaces along a different direction, you may shape | mold in the shape which has two surfaces along a different direction, or four or more surfaces. .

  Moreover, in the said embodiment, although the insert was attached to one mold and it was made to fill the hole of a three-dimensional molded product in the state which left the slight clearance gap, one mold was match | combined with the shape of the insert. You may provide the shaping | molding die of 2 types of shapes comprised in the shaping | molding die.

  Moreover, in the said embodiment, although the shaping | molding die was comprised from two type | molds, the upper mold | type 2 and the lower mold | type 3, you may comprise from 3 or more types | molds.

  In the embodiment, by using the same mold as the pair of molds that are clamped in a state where at least one of the outer surface and the inner surface of the three-dimensional molded article is covered with a resin film, The flat plate-like carbon fiber reinforced plastic was bent to obtain a three-dimensional molded product while reducing the equipment cost. For example, the flat plate-like carbon fiber reinforced plastic was bent by pressing it against the lower mold with a pressing roller. A molded product may be obtained.

DESCRIPTION OF SYMBOLS 1 ... Metal mold | die, 2 ... Upper mold | type, 2A ... Main body part, 2B ... Horizontal plate part, 2a ... Recessed part, 3 ... Lower mold | type, 3A ... Horizontal plate part, 3B ... Contact part, 3C ... Main body part, 3a ... Outer surface 4 ... Plate material (carbon fiber reinforced plastic), 4A, 4B, 4C ... hole, 5 ... resin film, 31 ... fixing part, 32 ... first recombination insert, 33 ... second recombination insert, 33A, 33B 33C ... protruding part, S, S1 ... gap

Claims (3)

  After forming holes in a flat plate-like carbon fiber reinforced plastic formed by impregnating the carbon fiber with a thermoplastic resin having a melting point lower than the melting point of the carbon fiber, the carbon is above the melting point of the thermoplastic resin and the carbon Three-dimensional molded product obtained by three-dimensional molding by bending the carbon fiber reinforced plastic heated at or below the melting point of the fiber while being softened or after being softened, and cooling the three-dimensional molded carbon fiber reinforced plastic In one of the molds having a pair of molds that can be freely opened and closed, with the holes of the three-dimensional molded product being buried leaving a slight gap, and among the outer surface and the inner surface of the three-dimensional molded product Molding on the side in contact with the resin film is set with at least one surface covered with a resin film molded with the same material as the thermoplastic resin or a thermoplastic resin with good compatibility The thermoplastic resin of the molten resin film is compressed by compressing the resin film by clamping the pair of molds while heating at a temperature higher than the melting point of the resin film and lower than the melting point of the carbon fiber. The one surface of the three-dimensional molded product is covered and the surface of the hole is covered by entering a slight gap of the hole, and then the one surface and the surface of the hole are covered with the thermoplastic resin by cooling. A method for processing a carbon fiber reinforced plastic characterized in that a three-dimensional molded product is obtained.   The method for processing a carbon fiber reinforced plastic according to claim 1, wherein a hole of the three-dimensional molded product is filled with a small gap left by attaching an insert to the one mold.   The method for processing a carbon fiber reinforced plastic according to claim 1 or 2, wherein the thermoplastic resin is an epoxy resin.

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