JP2671781B2 - Method for manufacturing FRTP preform - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a molded product made of FRTP (fiber reinforced thermoplastic resin), and in particular, it is easy to insert the molded product into a molding die, and voids are generated in the resulting FRTP molded product. The present invention relates to a method for manufacturing a FRTP preform that can be reduced in number and that, when laminating a plurality of FRTP prepregs or the like, positional deviation is reduced.

[0002]

2. Description of the Related Art Conventionally, FRTP molded articles having glass fibers, carbon fibers or the like as reinforcing fibers and a matrix of a thermoplastic resin such as nylon or polycarbonate have been used for transportation equipment, sports equipment and the like. The method of molding such an FRTP molded product is not impregnated (dry).
A type of preform such as a type FRTP prepreg was used as it was for a normal molding method such as a matched die molding method, a hollow internal pressure molding method, and an autoclave molding method.
Non-impregnated (dry) type FRTP prepregs include woven fabrics and sleeves made of commingle material, woven fabrics and sleeves made by interweaving reinforcing fibers and thermoplastic resin fibers, woven fabrics and sleeves made of powder prepreg, W with unidirectionally aligned reinforcing fibers and non-woven matrix
Woven cloths, sleeves and the like made of IP have been used.

[0003]

However, in the conventional FRTP molding method, since many voids are present inside the dry type FRTP prepreg, the preform becomes bulky and the inside of the mold that gives the shape is made. It was difficult to mold into the mold, and there was the inconvenience of biting burrs and wrinkles. Also, since it has many voids inside,
There is also a problem that voids are easily generated in the obtained FRTP molded product. Furthermore, when laminating a plurality of FRTP prepregs, there is a problem in that misalignment is likely to occur, which requires careful transportation after lamination, and the yield of obtained FRTP molded products is poor.

The present invention has been made in view of the above circumstances, and it is possible to reduce the bulkiness of a preform and to reduce FR.
Voids are less likely to occur in TP molded products, and multiple F
An object of the present invention is to provide a method for manufacturing a FRTP preform that does not cause a positional deviation when laminating RTP prepregs.

[0005]

The object of the present invention is to place a laminated body in which a reinforced fiber layer is sandwiched with a thermoplastic resin film larger than the reinforced fiber layer under reduced pressure, and under the reduced pressure , all the outer periphery of the laminated body is kept. The periphery is heat-sealed, then the reduced pressure is released, and both sides of the reinforcing fiber layer are attached to the thermoplastic resin film.
Sandwich the entire circumference of the thermoplastic resin film
It is solved by a method of producing a FRTP preform having a heat-sealed part .

[0006]

In the method for producing a FRTP preform of the present invention, the entire circumference of the outer periphery of the laminate is heat-sealed in a reduced pressure state so that the air existing inside the laminate is kept small and the reduced pressure is reduced. When released, the laminated body is pressed due to the pressure difference between the laminated body and the surroundings of the laminated body, so that the laminated body has a dense structure, so that the bulkiness of the preform can be reduced and a compact preform is obtained. To be further,
Even when laminating a plurality of reinforcing fiber layers or FRTP prepregs, since these reinforcing fiber layers and FRTP prepregs are covered with the thermoplastic resin film and vacuum-packed, the initial lamination relationship is maintained and the positional deviation is unlikely to occur. Become. Further, the outer surface of the reinforcing fiber layer is
By covering with a large thermoplastic resin film, it is possible to prevent foreign matter, dust and the like from entering the laminate. In addition, it is possible to adjust the melt viscosity and thickness of the thermoplastic resin film, and when the laminate is heated under reduced pressure , use of a thermoplastic resin film having a large melt viscosity causes excessive resin inside the laminate. Can be prevented from flowing out of the mold, and by adjusting the thickness, FRTP with the desired resin ratio can be obtained.
It is possible to obtain a preformed body.

Hereinafter, the present invention will be described in detail. FIG.
(A)-(E) is a process chart for explaining the 1st example of the manufacturing method of the FRTP preform of the present invention.
As shown in FIG. 1 (A), the reinforcing fiber layer 11 is sandwiched between the thermoplastic resin films 12 and 12 to produce a sheet-shaped laminate 13. Examples of the reinforcing fiber forming the reinforcing fiber layer 11 include carbon fiber, glass fiber, Kevlar fiber, and the like. The state of these reinforcing fibers is woven, aligned in one direction, or random. Either is fine. The thermoplastic resin film 12 is in the form of a flexible sheet, and examples of the material forming the thermoplastic resin film 12 include nylon, polyamide, polycarbonate, polyphenylene oxide, and liquid crystal polymer. Further, the reinforcing fiber layer 1
1 is FRTP consisting of reinforced fiber and thermoplastic resin
It may be a prepreg. Here, as the thermoplastic resin used for the FRTP prepreg, the same material as the material forming the thermoplastic resin film 12 is used, while as the reinforcing fiber, the same material as described above is used, but adhesion with the thermoplastic resin is used. In order to reinforce, it is preferable to use those which have been surface-treated beforehand with, for example, a silane coupling agent, a titanate coupling agent, a metal soap and the like. Further, the thermoplastic resin used for the reinforcing fiber layer 11 and the thermoplastic resin used for the thermoplastic resin film 12 are preferably the same.

Then, as shown in FIG. 1B, the laminated body 1
3 is placed on the jig 15, and the laminated jig 13 is held by the holding jig 16.
Hold down. The jig 15 used here is capable of mounting the laminated body 13 and is provided with concave portions or convex portions (concave portions in the drawing) for imparting a shape to the laminated body 13 on the mounting surface. The shape of the cavity 15a of the concave portion is the same as the shape of the outer shape of one side of the intended FRTP preform.

Next, as shown in FIG. 1 (C), the laminate 13 is placed in a vacuum chamber 19 connected to a negative pressure source (vacuum pump) 17 together with the jig 15, and then the negative pressure source 17 is placed.
Is operated to reduce the pressure in the vacuum chamber 19 and heat-seal the entire outer circumference of the laminate 13 with the heating element 18.
Here, the pressure in the vacuum chamber 19 after depressurization is preferably −400 mmHg or less in relative pressure. In this way, the cavity 15 of the jig 15 is attached to the laminated body 13.
The laminated body 13 is provided with a shape according to the shape of a.
The amount of air present inside is kept low.

Then, as shown in FIG. 1 (D), when the reduced pressure in the vacuum chamber 19 is released, the laminated body 13 is pressed due to the pressure difference between the laminated body 13 and the periphery thereof, and finally the laminated body 13 is evacuated to the vacuum chamber. Fig. 1 (E) when taken out from inside
The desired FRTP preform 23 is obtained as shown in FIG. The preform 23 has a small bulk and is compact. In this example, the example in which the laminated body 13 is produced first has been described, but the jig 1 is formed in order of the thermoplastic resin film 12, the reinforcing fiber layer 11, and the thermoplastic resin film 12.
5 may be laminated to produce a laminate 13, in which case the thermoplastic resin film 12 and the reinforcing fiber layer 1 are formed.
1. The same can be done by heating the thermoplastic resin film 12 before it is laminated on the jig 15 or by heating it after the lamination. The heating temperature is 100 to 200 ° C. when the material forming the thermoplastic resin film 12 is nylon, 130 to 250 ° C. when it is polycarbonate, 150 to 250 ° C. when it is polyphenylene oxide, and 180 to 3 when it is a liquid crystal polymer.
The temperature is preferably set to 50 ° C.

2A to 2C show the FRTP of the present invention.
It is a figure for demonstrating the 2nd example of the manufacturing method of a preform, Comprising: The manufacturing method of the 2nd FRTP preform shown in FIG. 2 is the same as that of the 1st FRTP preform shown in FIG. The difference from the manufacturing method is that the thermoplastic resin films 12 and 12 are preliminarily shaped by vacuum forming without using the holding jig 16. First, as shown in FIG. 2A, the thermoplastic resin film 12 is heated and softened while being clamped on the vacuum molding die 24, and the second negative pressure source (vacuum pump) 2
5 is operated to make the gap between the vacuum forming mold 24 and the thermoplastic resin film 12 into a vacuum, and the thermoplastic resin film 1
2 is brought into close contact with a vacuum molding die 24 to give a shape, and after cooling, the reduced pressure is released to take out the thermoplastic resin film 12.

Next, two sheets of the thermoplastic resin film 12 whose shape has been imparted by the above-mentioned vacuum forming are prepared, and the reinforcing fiber layer 11 is sandwiched between these thermoplastic resin films 12 and 12 to produce a laminate 13. Next, as shown in FIG. 2B, the laminated body 13 is placed on the jig 15.

Next, as shown in FIG. 2C, the laminated body 13 is put into the vacuum chamber 19 connected to the negative pressure source (vacuum pump) 17 together with the jig 15, and then the negative pressure source 17 is operated. Then, the inside of the vacuum chamber 19 is depressurized and the laminated body 13
The entire circumference of the outer circumference is heat-sealed with the heating element 18. In this way, the cavity 15a of the jig 15 is added to the laminated body 13.
The shape corresponding to the shape of (1) is given and the amount of air existing inside the laminated body 13 is kept small. Then
As in the first example shown in FIG. 1D, the reduced pressure in the vacuum chamber 19 is released, and finally the laminated body 13 is taken out from the vacuum chamber 19, which is similar to that shown in FIG. The FRTP preform 23 is obtained.

FIGS. 3A to 3C show the FRTP of the present invention.
FIG. 4 is a diagram for explaining a third example of the method for manufacturing the preformed body, and the method for manufacturing the third FRTP preformed body shown in FIG. 3 is the same as that of the first FRTP preformed body shown in FIG. 1. The difference from the manufacturing method is that the laminate 13 is tubular and the jig 1
5 is a tubular body 35. It should be noted that the jig 15 may be any one capable of defining the inner peripheral dimension of the laminated body 13 such as a columnar body or a flat plate. As shown in FIG. 3 (A), the laminated body 13 has a tubular reinforcing fiber 32 fitted on the outer circumference of an inner tube 31, and an outer tube 33 fitted on the outer circumference thereof. The material forming the inner tube 31 and the outer tube 33 is the same as the material forming the thermoplastic resin film 12, and the material forming the tubular reinforcing fibers 32 is the same as the material forming the reinforcing fiber layer 11. Things are used. As the tubular body 35, for example, a silicon tube is used.

In order to perform molding using such a laminated body 13 and a tubular body 35, as shown in FIG. 3B, the laminated body 13 is formed.
Before inserting into the vacuum chamber 19, the tubular body 35 is fitted inside the inner tube 31 of the laminated body 13 and removed from the laminated body 13 after the decompression in the vacuum chamber 19 is released. Do the same. In this way, the FRTP preform 23 as shown in FIG. 3 (C) is obtained. Before placing the laminated body 13 in the vacuum chamber 19, the tubular body 35 is pulled out and a release paper or the like is placed in the inner peripheral tube 31 at a portion to be heat-sealed so as to prevent the inner peripheral surfaces from being fused to each other, and then vacuumed. It may be placed in the chamber 19.

4 (A) and 4 (B) show the FRTP of the present invention.
It is a figure for demonstrating the 4th example of the manufacturing method of a preform, Comprising: The manufacturing method of the 4th FRTP preform shown in FIG. 4 is the same as that of the 3rd FRTP preform shown in FIG. The difference from the manufacturing method is that the inner tube 3 is used as the laminated body 13.
1 and the tubular body 35 are not used, and the one in which the outer periphery of the core 45 is covered with the tubular reinforcing fiber 32 such as a sleeve and the outer periphery thereof is covered with the outer tube 33 is used. The core 45 is capable of foaming at the molding temperature, and for example, hydrous sodium silicate, polyethylene containing a foaming agent, or the like is used. Such a laminated body 1
3. When molding is performed using the core 45, the FRTP preform 23 as shown in FIG. 4B in which the core 45 is foamed is obtained.

[0017]

As described above, according to the method for producing a FRTP preform of the present invention, the reinforcing fiber layer is formed from the reinforcing fiber layer.
Decompression of a laminate sandwiched with a large thermoplastic resin film
Place underneath, heat seal the entire circumference of the outer periphery of the laminate in a reduced pressure state , then release the reduced pressure , the reinforcing fiber layer
Sandwich both sides with the thermoplastic resin film,
By forming an FRTP preform in which the entire outer periphery of the thermoplastic resin film is heat-sealed , residual air inside the laminate is discharged to the outside and the inside of the laminate becomes airtight, so the bulk of the preform is high. Can be reduced
A compact FRTP preform can be obtained. Therefore, when such a preform is used, it is easy to mold it into a mold, and it is possible to reduce burrs and wrinkles. Further, since the residual air inside the laminate is discharged to the outside and the laminate has a dense structure, it is possible to reduce the voids in the preformed body, and thereby obtain the FRT.
It is possible to reduce the occurrence of voids in the P molded product. Furthermore, even when a plurality of reinforcing fiber layers or FRTP prepregs are laminated, since the reinforcing fiber layers or FRTP prepregs are covered with the thermoplastic resin film and vacuum-packed, the initial lamination relationship is maintained and the positional deviation occurs. There is an advantage that it is less likely to occur, and therefore, it is easy to carry after lamination and the yield of the obtained FRTP molded product is improved. Further, the outer surface of the reinforcing fiber layer is
By covering with a large thermoplastic resin film, it is possible to prevent foreign matter, dust, and the like from being mixed into the laminate, so that the storability is improved. Further, it is possible to adjust the melt viscosity and thickness of the thermoplastic resin film, and when the laminate is heated in a vacuum chamber, when the thermoplastic resin film having a large melt viscosity is used, the resin inside the laminate is It can be prevented from excessively flowing out of the mold, and by adjusting the thickness, a FRTP preform having a desired resin ratio can be obtained.

[Brief description of the drawings]

FIG. 1 is a process chart for explaining a first example of a method for producing a FRTP preform according to the present invention.

FIG. 2 is a diagram for explaining a second example of the method for producing a FRTP preform according to the present invention.

FIG. 3 is a diagram for explaining a third example of the method for producing a FRTP preform according to the present invention.

FIG. 4 is a drawing for explaining the fourth example of the method for producing a FRTP preform according to the present invention.

[Explanation of symbols]

11 ... Reinforcing fiber layer, 12 ... Thermoplastic resin film, 1
3 ... Laminated body, 15 ... Jig, 17 ... Negative pressure source, 18 ... Heating element, 19 ... Vacuum chamber, 23 ... FRTP preform, 31 ... Inside Tube, 32 ... tubular reinforcing fiber, 33
... outer tube, 35 ... tubular body, 45 ... core.

Claims (1)

(57) [Claims] 1. A laminate obtained by sandwiching a reinforcing fiber layer with a thermoplastic resin film larger than the reinforcing fiber layer under reduced pressure.
Then , heat-seal the entire outer periphery of the laminate in a depressurized state, and then release the depressurized pressure to remove both sides of the reinforcing fiber layer.
Sandwich with the thermoplastic resin film
FRT in which the entire circumference of the plastic resin film is heat-sealed
A method for producing a FRTP preform, which comprises obtaining a P preform .