JPH09277385A - FRP mold having warp adjustable mechanism and method of manufacturing FRP molded product - Google Patents

Abstract

(57) [Abstract] [Problem] It can be easily manufactured at low cost in a short period of time.
FRP that can be obtained without adjusting warpage and requiring special skill
Provided are a FRP molding die which has good dimensional accuracy of warpage and does not have a defect in appearance due to warpage countermeasures, and a method for manufacturing an FRP molded article using this molding die. SOLUTION: A FRP-made mold having a mechanism capable of freely adjusting the reverse warp in the opposite direction to the warp direction of the FRP-molded product, and a method for producing the FRP-molded product characterized by molding using the FRP-formed mold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an FRP mold for FRP (fiber reinforced plastic) molded products and a method for producing FRP molded products using this mold.

[0002]

2. Description of the Related Art FRP molded products are not molded according to the shape and size of the mold used in the molding process, and most of the molded products have a warp and are smaller than the mold. The cause of the warp is mainly due to the curing shrinkage of the material resin composition, and the cause of the undersize is that the curing shrinkage of the gel coat layer is small relative to the shrinkage during curing of the material resin composition, and the reinforcing fiber and the insert member do not shrink. Especially. The problem caused by the warp of the FRP molded product is very large. To give some examples, when a plurality of parts are combined, it becomes a major factor of mismatching of couplings, and a factor of hindering the utilization of FRP products in the field of complicated shaped parts. Also, in the field of using as a single item, it is not only a matter of appearance but also, for example,
In the case of a waterproof floor of a bath or the like, a target inclination angle cannot be obtained, and drainage is impeded, which causes a fatal functional problem.

Conventionally, the following methods have been used to improve the warp. (1) After the FRP molded product is molded, it is heated and softened, and a straightening jig that causes a reverse warp in a direction opposite to the direction of the warp is applied, and curing and cooling are performed to correct the warp within a target limit.
This is the so-called post-molding straightening method. (2) The mold is ground and an amount corresponding to the warp of the FRP molded product is corrected to reverse warp by a method of build-up. This is the so-called type correction method. (3) The mold corresponding to the warp of the FRP molded product is reversed and the mold is remanufactured. This is the so-called remolding method. However, these warp correction methods or warp prevention methods have many drawbacks as follows.

(1) Post-molding straightening method A heating furnace and a straightening jig are required, which increases equipment investment. The number of processes and man-hours will increase by the amount of the correction process, which will increase the cost and lead time to complete the product. On the surface of the FRP molded product, defects such as correction jig trace-shaped steps and surface roughness are likely to occur. Discoloration is likely due to the heat history of the heat softening process.
In particular, FRP molded products with gel coat resin applied on the surface are
Discoloration is a fatal defect. Further, depending on the heating conditions, there is a problem that the gel coat layer is cracked.

(2) Mold correction method Since the accurate warp dimension of the FRP molded product cannot be predicted at the designing and manufacturing stage of the molding die, the warp dimension of the FRP molded product is measured before the warp dimension of the mold is measured. Correct using methods such as grinding and padding. Since this mold modification requires a great number of man-hours and a lot of time, the cost for manufacturing the mold and the lead time increase. Since the warp correction of the mold is mainly for the processing of curves and curved surfaces, it requires a very high level of skill. This failure affects the appearance and dimensional accuracy of the FRP molded product. The strength of the part where the mold is ground and the buildup correction is inferior to that of the uncorrected part, and the life of the mold as a whole tends to be shortened.

(3) Mold Remanufacturing Method When the mold correction method and the post-molding straightening method cannot be used, a method of remanufacturing the mold is used. In this case, FRP
By modifying the wooden mold, which is the prototype of the molded product, by taking into account the warp of the FRP molded product, forming a FRP layer on the surface of the modified wooden mold, and peeling it off.
Remanufacturing the mold is time consuming and expensive.

[0007]

The inventions set forth in claims 1 to 4 are intended to solve the problems of the prior art, can be easily manufactured at low cost in a short period of time, and warp adjustment is a special skill. Therefore, the FRP molded product obtained does not require the above-mentioned FRP molded product, has good dimensional accuracy of warpage, and does not have a defect in appearance due to the warpage countermeasure. The invention according to claim 5 provides a method for producing an FRP molded product using this mold.

[0008]

SUMMARY OF THE INVENTION The present invention relates to an FRP mold having a mechanism capable of freely adjusting the reverse warp of the FRP molded product in the opposite direction to the warp direction. Further, the present invention relates to an FRP molding die in which, after adjusting an appropriate amount of reverse warp, the FRP molding die is fixed. The present invention also relates to an FRP mold, wherein these FRP molds are composed of an FRP mold layer, a mold support and a reinforcing material for connecting and integrating these layers. Further, in this FRP mold, the rigidity of the mold support is preferably higher than the rigidity of the FRP mold layer and the reinforcing agent. Furthermore, the present invention is characterized in that the molding is carried out using any of the FRP molds described above.
The present invention relates to a method for manufacturing RP molded products.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing an example of the FRP mold of the present invention. In FIG. 1, (a) shows a lower mold and a mold support frame, and (b) shows an upper mold. The lower mold 1 is integrated with a mold support frame 2 made of a member such as a steel frame. Lower mold 1 and mold support frame 2 as a mold support
Covers (overlays) the joint with FRP
By doing so, they can be integrated. FIG. 2 is a perspective view showing the mold support frame 2, in which the frame 3 on the entire upper side has the same size as the periphery or contour of the bottom surface of the lower mold.

Of the frames on the upper side of the mold support frame 2, the frames 4 and 5 on the long sides have relatively small rigidity, and the frames on the sides other than the frames 4 and 5 such as the frames 6 and 7 on the lower side have rigidity. Is large. In the frames 4 and 5 of the mold support,
Three bolts 8, 9, 10, 11, 12, 13 are connected, and bolts 14, 15, 16, 17, 18, 19 are connected to the lower frames 6 and 7 at positions facing them. The two bolts facing each other have a nut 2
0, 21, 22, 23, 24, 25 are attached to form a warp-adjustable adjusting mechanism. By turning these nuts left and right, these nuts can be deformed so as to warp the frame 4 or 5 up and down. In FIG. 1, bolts facing each other are tightened with nuts screwed to them so that the frames 4 and 5 are bent downward.
The nuts 21 and 24 in the middle are tightened so as to minimize the distance between the bolts 9 and 12, 15 and 18 to which they are screwed. Integrate the lower mold and mold support,
Attaching the bolts and nuts to the mold support is one example of a mechanism capable of freely adjusting the reverse warp in the direction opposite to the warp direction of the FRP molded product in the present invention.

The FRP mold can be manufactured by forming an FRP mold layer on a product prototype such as a wooden mold by a usual FRP mold manufacturing method. For example, a product prototype such as a wooden mold corresponding to a molded product is produced, and a reinforcing fiber such as a glass mat or a glass cloth is covered thereover, and a thermosetting resin such as an unsaturated polyester resin, a vinyl ester resin, or an epoxy resin. Is applied and cured by hand layup to form a lower mold FRP mold layer and then released, and then the product prototype is turned over to produce an upper mold FRP mold layer in the same manner, Release the mold. A mold support made of a member such as a steel frame is connected to the mold to be deformed by the FRP mold layer thus manufactured, and the FRP is molded with a reinforcing agent such as a hand layup so as to cross the connection boundary line. Then cover and integrate.

In the present invention, an example of the FRP mold is a FRP mold which comprises a FRP mold layer, a mold support and a reinforcing material for connecting and integrating these layers. in this case,
It is preferable that the rigidity of the frame support is higher than the rigidity of the FRP mold layer and the reinforcing agent because the warp of the FRP mold layer can be easily adjusted. The mold support and the FRP mold layer to be deformed may be integrated with a vise or a connecting device such as a bolt and a nut without using a reinforcing agent. Even in this case, it is preferable that the rigidity of the mold support is greater than the rigidity of the FRP mold layer. In the mold support made of a member such as a steel frame, the members (frames 4 and 5) contacting the mold layer made of FRP have such a rigidity that they are bent by the expansion and contraction force of the above-described warp adjustable mechanism, and other members are The rigidity is increased to such an extent that it is not bent by the expansion and contraction force of the warp adjustable mechanism, and the members (frames 6 and 7) having the high rigidity are used as the reference level for the warp.
Such rigidity can be adjusted by, for example, the size and thickness of the outer shape when a steel pipe is used as the support frame. Moreover, in the case of a square bar, it can be adjusted by the size of the cross-sectional area, the outer shape, and the like.

The warp of the FRP mold can be adjusted as follows. Using an FRP mold that does not warp, a FRP molded product is prototype-molded with the same specifications as the method used during mass production. FIG. 3 is a perspective view showing an example of the prototype molded product thus obtained. As shown in FIG. 3, the warp dimension L of the long side of the prototype molded product is measured. In the case of the prototype molded product as shown in FIG. 3, there is no warp at both ends of the short side and the long side, and the warp dimension of the long side can be measured based on these parts. After that, the warp adjustable mechanism is expanded and contracted with respect to the mold support member at the part of the FRP molding die corresponding to the warp part of the prototype molded product.
The manufactured mold layer is warped in the direction opposite to the warpage direction of the prototype molded product. The warp dimension of the FRP mold layer is finely adjusted centering on the value of the warp dimension of the prototype molded product.

The FRP molding die as shown in FIG. 1 which has been thus warped and corrected can be used as it is, but members similar to those of the mold support are connected by welding or the like. If the shape is fixed, that is, if the FRP mold of the present invention is fixed after adjusting the proper amount of reverse warp, it is possible to prevent the warp dimension from changing due to the looseness of the warp adjustable mechanism, etc. It is also possible to remove the telescopic jig of the warp adjustable mechanism and reuse it for other FRP molds.

FRP having a mechanism for freely adjusting the warp of the present invention
There is no limitation on the manufacturing method of the FRP molding to which it is applied, and the oldest hand layup method,
It can be applied to a wide range of FRP molding methods such as the spray-up method, the latest injection molding method, and vacuum injection molding method. In addition, the warp adjustable mechanism may be any jig as long as it can adjust the expansion and contraction between the mold support frame members of the FRP mold, such as the above-mentioned bolt and nut, vise,
Wire and chain wrenches, jacks, wedges, cylinders, turnbuckles, etc. are effective.

FIG. 1 shows an example in which a warp adjustable mechanism is attached to the lower mold, but depending on the shape of the FRP molded product,
It can be attached to the upper die or can be attached to both the upper die and the lower die to improve the warp prevention effect. The present invention is not limited to the lower mold, but can be applied to molds in all directions. Also, the telescopic jig of the warp adjustable mechanism is
It is not limited to the number used. It is preferable that wax is applied to the original mold when producing the FRP mold layer, and it is preferable that wax is applied to the FRP mold layer when producing the FRP molded product.

[0017]

In accordance with the present invention, it is essential that the FRP molding die used in advance be warped in the opposite direction by the warp dimension by using the expansion / contraction function of the warp adjustable mechanism, with respect to the warp direction and the dimension of the FRP molded article. Is. As a result, even if the FRP molded product is warped, the FRP molded product is preliminarily molded into a reverse warp.
An RP molded product is obtained. Further, an FRP mold having a freely adjustable warp mechanism can be obtained by simply attaching a commercially available general expansion / contraction jig, which serves as a freely adjustable mechanism of warp, to a conventional FRP mold, which has been conventionally performed. (1) Method of straightening after molding, (2) Method of correcting FRP mold by grinding, build-up, etc. (3) Modifying the original shape of product such as wooden mold and remanufacturing FRP mold Compared with the method, it is possible to easily and inexpensively produce a FRP molding die for mass production in a short period of time. Features such as excellent appearance.

[0018]

EXAMPLE An FRP mold as shown in FIG. 1 was produced (however, the nut and bolt were not tightened so that warpage would occur). FIG. 4 is a perspective view showing a rectangular window frame prototype. Using 50mm x 50mm square timber, make a rectangular window frame prototype with a long side of 1650mm and a short side of 680mm (both are outside dimensions) as shown in Fig. 4, apply wax to it, and then use it as a surface mat for a glass mat. (MFSO
P, Nitto Boseki Co., Ltd.) and a glass mat (MC450N, Nitto Boseki Co., Ltd.) stacked on top of this, and the unsaturated polyester resin composition (Polyset 6120S, Hitachi Chemical Co., Ltd.) 30% by weight of glass mat and resin 7 using Kogyo Co., Ltd.
A lower mold and an upper mold were produced by a hand lay-up method at a ratio of 0% by weight. The outer dimensions of the lower die are 1750 mm long side,
The short side is 780 mm and the thickness is 70 mm. Also, the upper mold has a long side 1
It is a plate having a length of 750 mm, a short side of 780 mm, and a thickness of 20 mm.

On the other hand, a frame support as shown in FIG. 2 was prepared. As for the frame, the frames 4 and 5 are 50 mm x 50 mm square and are made of square steel pipe with a thickness of 3.2 mm, and the other frames are 75 mm.
It is a square steel pipe having a size of 75 mm × 75 mm and a thickness of 3.2 mm. Each frame is connected to the weld. On the frame 4, M16 bolts with opposite screws are opposed to each other and a total of 3
Welded together. Similarly, for the other frame 5, M1
Welded 6 bolts facing each other. One nut was attached to the two opposing bolts. In the frames 4 and 5, the central bolt was installed in the middle of the frame, and the other frames were installed 300 mm from the ends of the frame.

The lower mold is placed on the frame support, and the joint is 50 mm on the frame side and 50 mm on one side, and the same glass mat and resin are used (however, the surface mat is used). (No) Hand reup, integrated lower mold and frame support. However, not shown.

Next, a gel coat-coated FRP window frame was molded using the FRP molding die manufactured as described above. First, wax was applied to the lower mold, and then a gel coat resin (vinyl ester resin, PCG-9B-240, trade name of Tokyo Ink Co., Ltd.) was applied to a thickness of 0.6 mm.

After that, a glass mat (MFSOP, a product name of Nitto Boseki Co., Ltd.) was used as a surface mat, and a glass mat (MC450N, a product name of Nitto Boseki Co., Ltd.) was used on top of this, and was not used as a resin. A glass mat 30 using a saturated polyester resin composition (Polyset 6120S, trade name of Hitachi Chemical Co., Ltd.)
Hand up at a ratio of 70% by weight and resin,
A piece of wood with a thickness of 35 x 35 mm, which serves as a frame and extender, is inserted in a square shape at the portion corresponding to the center of the FRP layer, and as a glass mat (MCL450N, Nitto Boseki Co., Ltd.) and resin. Is an unsaturated polyester resin composition (Polyset 6120S, trade name of Hitachi Chemical Co., Ltd.), 30% by weight of glass mat and 70% of resin
After forming the FRP layer by hand-up at a rate of weight%, the upper mold was placed, and the key parts were fixed to the lower mold with a clamp to mold.
The FRP window frame thus obtained had a maximum warp of 5 mm at the center of the long side of the window frame with the gel coat side as the inside. Further, there was no warp within 100 to 150 mm from both ends of the short side and the long side.

Then, the bolts and nuts of the frames 4 and 5 were tightened, and the FRP type layer of the lower type was lowered to the lower side by a maximum of 5 mm (opposite warpage of the product). The bolts and nuts other than the center of the frames 4 and 5 were tightened so that the warp was about ⅔ of the maximum warp. Using this mold, molding was performed with the same specifications as the above-mentioned conventional method. However, the lower die and the upper die are clamped with a vise so that the upper die follows the warp of the lower die. The warp of the FRP window frame thus obtained was 0.5 mm at maximum.

[0024]

EFFECTS OF THE INVENTION According to the FRP molding die of the first to fourth aspects, it is possible to prevent the warp occurring in the molding process of the FRP product, and to give the FRP product any warp in the molding process. it can. In particular, the FRP mold according to claim 3 or 4 is to remanufacture the FRP mold after correcting the mold of grinding or overlaying the FRP mold or warping the original product such as a wooden mold. Compared with conventional methods such as the method, it is very inexpensive and can be corrected in a short time. Since no special technique required for correction is required, there is an advantage that even unskilled people can correct warpage. The life of the mold is longer than that of the FRP mold that has been built up and modified.
By the method according to the fifth aspect, it is possible to manufacture a FRP molded product having an excellent appearance by freely adjusting the warpage or adjusting the warpage.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of an FRP molding die of the present invention. In FIG. 1, (a) shows a lower die and a die support frame, and (b) shows an upper die.

FIG. 2 is a perspective view showing a mold support frame.

FIG. 3 is a perspective view showing an example of a prototype molded product.

FIG. 4 is a perspective view showing a rectangular window frame prototype.

[Explanation of symbols]

 1 Lower mold 2 Type support frame 3 Frame on the entire upper side 4, 5 Frame on the long side 6, 7 Frame on the lower side 8, 9, 10, 11, 12, 13 Bolts 14, 15, 16, 17, 18, 19 Bolts 20 , 21, 22, 23, 24, 25 nuts

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mune Sugano 5-12-15 Namerikawa Honcho, Hitachi City, Ibaraki Prefecture

Claims (5)

[Claims] 1. A molding die made of FRP having a mechanism capable of freely adjusting a reverse warp in a direction opposite to a warp direction of an FRP molded product. 2. The FRP mold according to claim 1, wherein the proper amount of reverse warp is adjusted and then fixed. 3. The FRP mold according to claim 1 or 2, wherein the FRP mold comprises an FRP mold layer, a mold support and a reinforcing material for connecting and integrating these layers. 4. The FRP mold according to claim 3, wherein the mold support has a rigidity higher than the rigidity of the FRP mold layer and the reinforcing agent. 5. The FRP according to any one of claims 1 to 4.
A method for producing an FRP molded product, which comprises molding using a molding die.