JPH0620790B2 - Method for manufacturing glass fiber reinforced plastic molded product - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a glass fiber reinforced plastic molded product used as a core material or the like of an air spoiler.

(Prior Art) In recent years, as shown in FIG. 6, an air spoiler S mounted to increase the high-speed stability of a vehicle tends to increase in size in order to enhance its function. However, the weight of the air spoiler tends to increase as the size increases. Therefore, in order to reduce the weight, No. 60-6685 or No. 61-12885
JP-A No. 2003-242242 proposes a plastic low-density foam as a core, and the surface of the core is further covered with a plastic outer layer. However, the one made of only plastic such as No. 60-6685 is excellent in lightness, but has a drawback that mechanical strength is inferior. On the other hand, it cannot be denied that the metal reinforcing body is heavy in the structure in which the metal reinforcing body is embedded therein as in Japanese Utility Model Laid-Open No. 61-12885, and the total weight becomes large.

The applicant therefore proposed in Japanese Patent Application No. 62-20307 an air spoiler in which a low-density foam is covered with a solid plastic reinforced with glass fibers, and a glass fiber reinforced plastic molded product having increased rigidity is further covered with foam plastic. Proposed. As disclosed in Japanese Patent Application No. 62-20307, the manufacturing method is as follows. First, a low-density plastic foam coated with glass fiber such as continuous strand mat is placed in a first split mold having a predetermined cavity shape. Then, the raw material is impregnated into the glass fiber by injecting a reactive plastic raw material such as polyurethane resin into the void formed by the surface of the low density foam and the inner surface of the first split mold, and the low density foam is formed. A glass fiber reinforced plastic molded product is formed by coating on the body and reinforcing the low density foam with glass fiber. Next, this molded product is placed in a second split mold having a predetermined spoiler-shaped cavity, and a foamed plastic raw material such as polyurethane foam is placed in the void formed by the surface of the molded product and the inner surface of the second split mold. To form a predetermined foamed plastic layer on the molded article by injecting or injecting.

In this case, the foamed plastic layer constituting the spoiler surface has a main purpose of improving the surface properties, such as smoothness and appearance, of the glass fiber reinforced plastic molded product which is the core body, and therefore it is about 5 to 10 mm. It is a thin layer.

(Problems to be Solved by the Invention) However, it has been found that the following problems occur in manufacturing a spoiler by the above method.

This is because when the product (spoiler) is further coated to improve its surface properties and imparts decorative properties, and is subjected to a baking treatment, the product surface is partially swollen or is slightly depressed. This often means that recesses are created. Such a defect is a serious defect because the spoiler is also an outfitting component on the outer surface of the vehicle body.

The present inventor has diligently studied this problem, when molding a glass fiber reinforced plastic molded product as a core, that is, a reactive plastic raw material such as polyurethane is coated with a low-density foam as a core. When impregnating into a Nures Strand mat or the like, although a coating layer of glass fiber reinforced plastic having an apparently smooth surface is formed by the split mold inner surface, in the coating layer of the reinforced plastic,
It was confirmed that quite a few small air bubbles, voids, etc. were present. Then, it was found that air bubbles and the like existing immediately below the surface of the coating layer expanded during baking of the coating film, and further ruptured and affected the foamed plastic layer coated thereon.

The reason why these bubbles can be formed is not clear, but one of them is that the glass fiber mat itself has a considerable variation in fiber density, and the plastic raw material is not uniformly impregnated,
Air is entrained to flow between the fibers, and since the glass fiber mat is compressed by the surface of the low-density foam and the inner surface of the first split mold, the air present between the entangled fibers or the closed air is reduced. It is presumed that the raw material is caught in the raw material, or the volatile component in the raw material and the gaseous reaction product remain in the molded product.

A continuous strand mat or the like is a strand obtained by bundling hundreds of glass fiber monofilaments (usually having a wire diameter of 10 to several tens of μm), or 10 to several tens of these strands. It is made into a mat shape, and the fiber diameter of the glass fibers that make up the mat is large, and although it has an excellent reinforcing effect, the voids due to the entanglement of the fibers are rough, which creates air retention areas in places by compression with the above-mentioned mold. Combined with the non-uniform flow due to the glass fibers of the coated plastic raw material, voids larger than air bubbles (voids) and further concave recessed portions are formed on the surface of the coating layer.

(Means for Solving the Problems) Accordingly, the present invention is to provide a novel method for producing a glass fiber reinforced plastic molded article which solves the above problems, and the gist thereof is to provide a glass fiber mat. A foamed plastic core laminated on the surface of the core is placed in a predetermined mold, and after the mold is closed, the core is formed by the core surface and the mold inner surface, and the glass fiber mat is sandwiched in the existing cavity. A glass in which a reactive plastic raw material is injected, a glass fiber mat is impregnated with the raw material, and a foamed plastic core is coated with the raw material, and a glass fiber reinforced plastic layer is integrally formed on the foamed plastic core by reaction curing. In the method of manufacturing a fiber-reinforced plastic molded product, it is common to stack a glass fiber mat with two or more glass fiber mats having different wire diameters. In the method for producing a glass fiber reinforced plastic molded article, a glass fiber mat having a smaller wire diameter is placed on the surface side of the molded article and molded.

(Function) In the two-layer glass fiber mat laminated and coated on the foamed plastic core, the glass fiber mat having a smaller wire diameter is arranged on the surface side of the molded product. Therefore, on the surface side of the laminated glass mat, voids between fibers are continuous with fine spaces, and the void ratio is larger than that of the glass mat made of fibers having a large wire diameter on the side of the foamed plastic. When the core body is installed in the split mold, the glass mat having a smaller wire diameter is in contact with the split mold inner surface. Therefore, when the reactive plastic raw material is injection-pressed into the cavity formed by the foamed plastic surface and the split mold inner surface in the state where the laminated glass mat is sandwiched, the raw material is injected into both layers of the laminated glass mat. Although it is impregnated, at this time, the glass mat with a large wire diameter on the foamed plastic side may be impregnated while entraining air or the like as in the conventional case, but in the glass mat with a small wire diameter on the mold surface side, Due to the high porosity and the capillary phenomenon, air is impregnated with almost no entrainment to form a dense, smooth surface-free surface layer reinforced with fine glass fibers and having almost no defects. Therefore, even if air bubbles or voids exist under the surface layer, thermal expansion of the air bubbles or voids is suppressed by the reinforcing plastic layer on the surface. Further, since the surface of the molded article has almost no defects as described above, even if a non-foamed or reporting plastic layer for imparting decorative properties is further formed on the surface of the decorative coated layer, Almost all the defects caused by the glass fiber reinforced plastic molded product appear.

(Example) The present invention will be described below by taking an example of manufacturing a spoiler which is an example.

FIG. 1 is a sectional view of a mold showing a method for manufacturing a spoiler core body which is a glass fiber reinforced plastic molded product of an embodiment of the present invention, FIG. 2 is an enlarged sectional view of part A thereof, and FIG. FIG. 4 is an enlarged cross-sectional view of a spoiler core manufactured by the method, FIG. 4 is a cross-sectional view of the spoiler in which a decorative foamed plastic layer is further coated on the spoiler core, and FIG. 5 is decoration of the spoiler of FIG. It is sectional drawing of a type | mold which shows formation of a functional coating layer.

The spoiler core body according to the embodiment of the present invention is manufactured as follows. First, a glass mat 20 is coated on a foamed plastic molded product 10 which is molded in a desired shape in advance, and the glass fiber mat-covered foamed plastic molded product is installed in a predetermined split mold 30. At this time, a predetermined gap (cavity) 33 is set between the surface of the foamed plastic molded product 10 and the inner surface of the split mold 30, and the split molds 32, 32 of the split mold 30 are closed. At this time, the glass mat 20 is held in the cavity 33 so as to be sandwiched between the surface of the foamed plastic molded product 10 and the inner surface of the split mold 30.

The glass mat 20 has two kinds of glass mats 21 and 2 with different wire diameters.
The glass mat 21 made of glass fibers having a smaller wire diameter is arranged on the inner surface side of the mold 30, in other words, on the surface side of the molded product, and the glass having a larger wire diameter is laminated. A glass mat 22 made of fibers is arranged on the surface side of the foamed plastic molded product.

As a glass fiber mat having a small wire diameter, a glass fiber monofilament having a wire diameter of 10 to 10 μm is randomly and evenly dispersed and formed into a mat with a binder, but is not limited to the monofilament. Alternatively, it may be a mat-shaped product obtained by bundling dozens of them.
Since this glass mat is made of glass fibers having a small wire diameter as described above, the entangled portions between the fibers are thin and the surface is even and smooth. Moreover, since the fibers are thin, the porosity between the fibers is high.

On the other hand, as a glass fiber having a large wire diameter, hundreds of the monofilaments are bundled, what is called a normal strand, or further 10 to several tens of these strands are bundled, particularly the continuous fiber. It is preferable to disperse and bond the nustr strands in the same manner as described above to form a mat in order to reinforce the impregnating plastic described later. If necessary, two or more layers of these glass mats may be laminated to increase the strength of the glass fiber reinforced coating layer 40 described later.

The glass mat 21 with a smaller wire diameter is placed on the inner surface of the mold.
Since it is intended to make the surface of the glass fiber mat having a large wire diameter arranged on the foam side uniform, it may be a thin layer, and in the embodiment, as the glass mat 21 having a small wire diameter, a basis weight of 30 g / m ^2, using what apparent thickness of about 0.2 mm, a glass mat 22 made large in diameter, basis weight of 600 g / m ^2, was used in the apparent thickness of about 5 mm. A fixture such as a bolt (not shown) was embedded so that its head was located in the glass mat.

Then, the laminated glass mat 20 is divided into molds so as to be sandwiched between the surface of the foamed plastic molded product 10 and the inner surface of the mold 30.
Close 31, 32 and hold in cavity 33. At this time, the gap between the cavities 33 holds the glass mat, and thus is smaller than the thickness of the laminated glass mat 20. In this embodiment, the cavity gap is set to 1.5 mm to 2.0 mm. By this closing mold, the glass mat 20 is compressed and its thickness is reduced, but it goes without saying that it can be filled while being impregnated with the plastic raw material described later only by reducing the voids.

In this state, a reactive plastic material such as polyurethane, which is a hard plastic, is injected or press-fitted from the injection hole 34 of the mold 30 to fill the cavity 33. The filled plastic raw material fills the cavity while impregnating the glass mat 20 held in the cavity 33 as described above, and covers the surface of the foamed plastic molded product. The reactive plastic raw material is not limited to polyurethane, and may be any other raw material as long as it reacts to form a hard plastic. However, since the glass mat 20 is impregnated as described above at the time of filling the raw material, an initially liquid raw material is preferable, and as such a raw material, the above-mentioned polyurethane raw material containing isocyanate or its modified product as one main component. Similarly, there are liquid raw materials containing isocyanate or a modified product thereof as a main component, and further, acrylic derivatives which are polymerized into a polymer, raw materials for monomer casting such as caprolactam, and the like. Isocyanate is the main component, the isocyanate is trimerized to produce a hard isocyanurate polymer,
The monomers are each polymerized into a polymer such as acrylic resin or polyamide.

The filled reactive plastic raw material flows so as to impregnate the glass mats 21 and 22 laminated as described above. At that time, there is a high possibility that air or the like will be entrained in the glass mat 22 having a large wire diameter, and the coating layer 42 having bubbles or the like inside is formed, but the glass mat 21 having a small wire diameter has a high porosity. Therefore, the dense coating layer 41 is formed with almost no air entrapment. The state is the third
Shown in the figure. Then, the mold 30 is opened after the reaction curing of the coating layers 41 and 42, and the hard plastic coating layer 40 reinforced with glass fibers.
The glass fiber reinforced plastic molded product having is removed from the mold.

Then, the glass fiber reinforced molded product is placed in a mold 60 having a predetermined spoiler-shaped cavity 63 as shown in FIG. 5, and a non-foamed or foamed plastic raw material is injected from the injection hole 64 in the same manner as described above. Alternatively, the desired plastic coating layer 50 is formed on the glass fiber reinforced plastic molded product by press fitting. For example, if a soft feel is desired on the spoiler surface, a plastic material that produces a soft polyurethane foam or the like is injected. After that, coating is applied on it according to a desired color or the like. The formation of the plastic coating layer 50 is not limited to injection (press-fitting), the raw material for forming the coating layer 50 is injected with the mold 60 opened, and then the mold is closed to form the coating layer 50. You may do it.

In forming the glass fiber reinforced plastic molded product and forming the coating layer 50 to be the surface of the spoiler,
When applying a release agent to the inner surface of the mold, the coating layer 50 is a post-process.
Prior to the formation and coating steps, each molded product is washed with an organic solvent or the like to remove the release agent.

In the present invention, the foamed plastic molded product 10 which is the core of the original glass fiber reinforced plastic molded product is molded in advance into a predetermined shape from a foamed plastic raw material such as polystyrene. As the foamed plastic molded article, any plastic molded article can be used, but a foamed plastic molded article having a closed cell structure made of polystyrene, polyethylene, polypropylene or a copolymer thereof is preferable. In order to obtain the foamed plastic molded product 10, it is possible to separately form the plastic bead material by a known bead foam molding from a foaming material obtained by impregnating a volatile solvent or the like.

In the above description, the manufacturing of the spoiler is described as an example, but the present invention is not limited to this, and it goes without saying that the spoiler can be used for manufacturing various articles.

(Effect) In the present invention, two or more glass mats having different wire diameters as described above are coated on a foam-molded article so that the glass mat made of fibers having a small wire diameter is on the front side, Since it is installed in a mold and impregnates the glass mat with the reactive plastic raw material and coats the foamed molded article, it has almost no defects such as bubbles on the surface side of the coating layer,
Moreover, a surface layer reinforced with glass fibers having a small wire diameter is formed. Therefore, even if bubbles or the like are present under the surface layer and heat or the like is applied, the bubbles or the like are suppressed by the surface layer, and there is almost no possibility that the surface is swollen or the surface layer is destroyed. Moreover, as mentioned above, since the surface of the surface layer has almost no defects,
Furthermore, even if a desired coating layer is formed thereon, most of the defects caused by the glass fiber reinforced molded article are eliminated on the surface of the coating layer.

Further, even if the glass fiber reinforced molded product is manufactured, it is only necessary to laminate two kinds of glass mats or the laminate thereof on the foamed molded product, and the process can be simplified and a great effect can be obtained. It is a thing.

On the other hand, the glass fiber reinforced molded product produced in this manner is lightweight because it has a foamed inside, and is suitable as a core body suitable for various uses such as a spoiler that requires lightweight.

[Brief description of drawings]

FIG. 1 is a sectional view of a mold showing a method for producing a glass fiber reinforced plastic molded article according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of an A portion thereof, and FIG. 3 is a molded article produced by the method of the present invention. FIG. 4 is an enlarged cross-sectional view of a portion A, FIG. 4 is a cross-sectional view of a product (spoiler) on which a covering layer of foamed plastic is further formed, and FIG. 5 is a cross-section showing a method of forming the covering layer of FIG. FIG. 6 and FIG. 6 are perspective views of the rear portion of the vehicle body equipped with the spoiler.

Claims (1)

[Claims] 1. A foamed plastic core body having a glass fiber mat laminated on the surface is placed in a predetermined mold, and after the mold is closed, the core body surface and the mold inner surface are formed, and the glass fiber mat is sandwiched. As described above, the reactive plastic raw material is injected into the existing cavity, the raw material is impregnated into the glass fiber mat and the foamed plastic core is coated, and by the reaction curing, the glass fiber reinforced on the foamed plastic core. In a method for producing a glass fiber reinforced plastic molded article in which a plastic layer is integrally formed, a glass fiber mat is laminated from two or more glass fiber mats having different wire diameters, and a glass fiber mat having a smaller wire diameter is formed on the surface of the molded article. A method for producing a glass fiber reinforced plastic molded product, which is characterized in that it is arranged on the side and molded.