JPH10166467A - Continuous forming method of light-weight multilayer resin product and continuous forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a production line and prevent an outer layer from becoming non-uniform in thickness and becoming insufficient impregnation by first accelerating the curing process of a composite material of reinforcing fiber and thermosetting resin and at the same time, supplying a foaming resin liquid into an inner space surrounded by the outer layer for the foaming and setting of the liquid, and further, drawing the outer layer, while filling the inner space. SOLUTION: A reinforcing fiber 9 is soaked in a resin liquid 7 for impregnation in an outer layer impregnation resin tank 6 to undergo an impregnation process and this fiber 9 impregnated with a heat-curing resin liquid is guided to the inlet part 1a of an outer die 1. Further, a core 2 is provided in the inlet part 1a and the impregnated fiber 9 is supplied into a space between the outer die 1 and the core 2. In addition, the impregnated fiber 9 is drawn for forming while the former is thermally cured by a heating means 1c. On the other hand, an inner layer resin liquid 5 to be discharged from the tip of the core 2, is injected under pressure into the inside of the outer die 1 and receives a reaction heat from the heating means 1c and a thermosetting resin on the outer layer side. When using a foaming resin liquid as the inner layer resin liquid 5, a foaming process occurs immediately. The filling and foaming of the inner layer resin liquid 5 are started after the curing reaction of the thermosetting resin, so that it is possible to prevent the wall thickness of the outer layer from becoming non-uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously producing, with good productivity, a multilayer resin product in which the inner layer is composed of a bubble-containing resin layer and the outer layer is composed of a fiber-reinforced thermosetting resin layer. And devices.

[0002]

2. Description of the Related Art A composite product in which a thermosetting resin is reinforced with a reinforcing fiber such as glass fiber is a so-called fiber reinforced resin (FRP).
It is widely used in various fields as a product. If the FRP product has a relatively simple cross-sectional shape such as a circular shape, an elliptical shape, a rectangular shape, a T-shape, a U-shape, a flat shape, or a corrugated shape, a drawing with a heating mechanism is required. Using a molding device, the composite material of the reinforcing fiber and the thermosetting resin is continuously fed in from the inlet side, and the thermosetting resin is heated and cured by the molding device, and the molding material is discharged from the outlet of the molding device. A method of continuously and efficiently producing a long FRP material by continuously extracting a cured molded body from the side is adopted.

A core is installed on the inner surface of the inlet of the above-described drawing apparatus, and the inner surface is regulated by the core to perform the heat forming and the drawing, so that the cross-sectional shape is O-shaped. There is also known a method of manufacturing a hollow long product having a shape such as a square shape or a square shape.

[0004] Solid type and hollow type long FRP products manufactured by these methods can be properly used depending on their use and required characteristics.
Although the product has excellent bending strength and compression strength, it has a problem in lightness.On the other hand, hollow type FRP products can be made lighter by changing the thickness and adjusting the degree of hollowness. On the other hand, deficiencies in bending strength and compression resistance are inevitable.

[0005] Therefore, as an eclectic product of the solid product and the hollow product, an FRP product having both lightness and strength characteristics has been developed by providing a bubble-containing resin layer in the hollow portion of the solid product. In this type of FRP product, the weight reduction is enhanced by the bubble-containing resin layer constituting the inner layer, and the presence of the bubble-containing resin layer also significantly increases the bending strength and the compression resistance as compared with the hollow product. Also, by adjusting the ratio of the bubble-containing resin layer by changing the thickness of the outer layer, there is obtained an advantage that strength and lightness can be ensured according to the intended use.

As described above, as a method of manufacturing an FRP product provided with a bubble-containing resin layer as an inner layer, for example, a method disclosed in Japanese Patent Publication No. Hei 2-503772 has been proposed.

In this method, an inner layer containing air bubbles is formed in advance by a pre-die former and a die station provided on the upstream side of a pultrusion molding apparatus, and subsequently, it is led to a forming die section and heat is applied to an outer peripheral side thereof. This is a method in which a curable resin is injected and thermally cured to form and pull out the outer layer, and is evaluated as a technology that enables continuity.

However, this method still has room for improvement in the following points. This is a method in which the formation of the inner layer and the molding and curing of the outer layer are sequentially performed, and there is a concern that the production line becomes longer and the production speed becomes slower. After forming the inner layer, it is a method of forming an outer layer by injecting a thermosetting resin to the outside without any special centering means,
The thickness of the outer layer may be partially uneven. FIG. 1 of the above publication discloses a method in which the inside of the reinforcing fiber cloth is filled with a granular indenting material by a blower, guided to a die station, and impregnating resin is injected from the outer surface side to be impregnated and hardened and pulled out. Although disclosed, this method requires a considerable high pressure and time to impregnate the resin into the entire inner layer, and if the pressure and time are insufficient, there is a concern that insufficient impregnation may cause a strength defect.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in order to improve the above-mentioned problems.
The inner layer is a resin layer lightened by containing bubbles or a porous material, and the outer layer is used for producing a multilayer resin product constituted by a fiber-reinforced thermosetting resin layer. We have improved the problems that may be of concern, shortened the production line and improved productivity, and achieved stable, high-quality, lightweight composites without problems such as non-uniform outer layer thickness and insufficient impregnation. It is an object of the present invention to provide a method and an apparatus capable of obtaining a layer resin product.

[0010]

Means for Solving the Problems The method of the present invention, which can solve the above-mentioned problems, comprises a multilayer resin product in which the inner layer is composed of a bubble-containing resin layer and the outer layer is composed of a fiber-reinforced thermosetting resin layer. In a method of manufacturing by a pultrusion molding method, while curing a composite material of a reinforcing fiber and a thermosetting resin in a state where the composite material is restricted to the outer layer shape, a foamable resin liquid is supplied to an internal space surrounded by the outer layer. Then, the foamable resin liquid is solidified while being foamed, and is withdrawn while filling the internal space, or while the composite material of the reinforcing fiber and the thermosetting resin is cured in a state where the composite material is regulated to the outer layer shape, The gist is that a resin liquid containing air bubbles or a porous material is supplied to the internal space surrounded by the outer layer, and the resin liquid is hardened or solidified and the inner space is filled out and pulled out. A continuous molding of a lightweight composite resin products.

The continuous molding apparatus according to the present invention is a drawing mold for producing a multilayer resin product in which the inner layer is composed of a resin layer containing air bubbles or a porous material, and the outer layer is composed of a fiber-reinforced thermosetting resin layer. A continuous molding apparatus, wherein an outer mold having a heating mechanism for regulating and molding to the outer layer shape, and a gap corresponding to the outer layer shape is provided between an inner surface of the outer mold and an inner side of an inlet of the outer mold. The core is provided, and the core is provided with a supply unit for supplying the resin material constituting the inner layer toward the internal space surrounded by the outer layer shape, and preferably further provided with a cooling mechanism. Where there is a gist.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, in the present invention, when a multilayer resin product having an inner layer composed of a bubble-containing resin layer and an outer layer composed of a fiber-reinforced thermosetting resin layer is manufactured by a pultrusion molding method. The composite material of the reinforcing fiber and the thermosetting resin is cured in a state where the composite material is restricted to the outer layer shape, and a foamable resin liquid is supplied to an internal space surrounded by the outer layer to foam the foamable resin liquid. Pulling out while solidifying and filling the inner space, or curing the composite material of the reinforcing fiber and the thermosetting resin in a state where the outer layer shape is regulated, and bubbles in the inner space surrounded by the outer layer. Alternatively, a resin liquid containing a porous material is supplied, and the resin liquid is hardened or solidified while filling the inner space and pulled out. And heat curing of the composite material of the RESIN supply of foamable resin forming the inner layer,
The foaming and solidification are performed simultaneously and concurrently, or the supply of the foam or the porous material-containing resin constituting the inner layer and the heat curing (or cooling and solidification) are simultaneously performed in parallel, and the inner layer is surrounded by the outer layer shape. By pulling out while filling the components, it is possible to shorten the continuous production line and improve the production speed.

Furthermore, when the apparatus of the present invention is used, the heating means provided in the drawing apparatus heats and cures the composite material of the reinforcing fibers and the thermosetting resin constituting the outer layer from the inner surface side of the apparatus, After the heat curing of the composite material has progressed, the filling of the foamable resin or the thermosetting resin containing bubbles (or porous material) constituting the inner layer and the heat foaming or thermosetting proceed, so that the outer layer is not preferable. It is possible to efficiently and continuously produce an FRP product having no strength defect without a risk of uneven thickness or insufficient impregnation on the inner layer side.

Hereinafter, the specific configuration, operation, and effects of the present invention will be described in detail with reference to the drawings showing an embodiment of the present invention. However, the present invention is not limited to the illustrated examples. It is also possible to carry out the present invention with appropriate modifications within a range that can be adapted to the gist of the preceding and following descriptions, and they are all included in the technical scope of the present invention.

FIG. 1 is a schematic explanatory view illustrating a typical continuous molding apparatus and a continuous molding method according to the present invention. In FIG. 1, 1 is an outer mold, 2 is a core, 3a and 3b are tooling guides, and 4 is a tooling guide. Inner layer resin tank, 5 is an inner layer forming resin liquid made of a foaming resin liquid (or a resin containing bubbles or a porous material), 6 is an outer layer impregnating resin tank, and 7 is an outer layer impregnating resin made of a thermosetting resin liquid. Liquid, 8 is a drawn product, and 9 is a reinforcing fiber.

In carrying out the present invention using the apparatus shown in the figure, the reinforcing fibers (long fiber group, net, cloth, etc.) 9 drawn out from the right side of the drawing are impregnated for the outer layer by a dipping guide or the like (not shown). After being immersed in the impregnating resin liquid 7 in the resin tank 6 to be impregnated, passing through a not-shown squeezing roller and the like, it is guided to the inlet 1a of the outer mold 1 in the pultrusion molding device via the tooling guides 3a and 3b. In the example shown in the drawing, the reinforcing fiber 9 is sufficiently arranged at least on the entire outer surface side in accordance with the shape of the final molded product.
Supply can be made from the top, bottom, left and right so as to cover the entire area of a. The supply position should be arbitrarily selected according to the cross-sectional shape of the final molded product.

At the inlet 1a of the outer mold 1, a core 2 is provided with a gap corresponding to the outer layer shape between the core 2 and the molding surface (inner peripheral surface) of the outer mold 1 as shown in the figure. The reinforcing fibers 9 impregnated with the outer layer impregnated resin liquid 7 are guided into this gap.

As shown in the enlarged sectional view of FIG. 1 (a), the core 2 penetrates the shaft core as shown in the enlarged cross-sectional view of FIG. 1 (a), and is made of a foamable resin liquid (or a resin liquid containing bubbles or a porous material). A supply hole 2a for supplying the inner layer resin liquid 5 is provided as a resin liquid supply means, and preferably, a branch path 2b directed to the outer peripheral direction is provided at a tip portion thereof. 5 is configured so as to be evenly distributed over the entire internal space surrounded by the outer layer. Reference numeral 2c denotes a coolant channel such as water provided as necessary to prevent the core 2 from rising in temperature. When a heat-foamable resin or a thermosetting resin liquid is used as the inner layer resin liquid, the core 2 It is preferably provided to prevent the internal layer resin liquid 5 from being foamed or hardened in the supply hole 2a or the branch path 2b due to a rise in temperature, thereby causing the passage to be blocked.

The rear end of the supply hole 2a provided in the core 2 is connected to the inner layer resin tank 4 via the connecting pipe 10, and the front end is immersed and opened in the inner layer resin liquid 5. In the illustrated example, the inner layer resin tank 4 has a sealed structure, and the liquid level of the inner layer resin liquid 5 in the tank 4 is pressurized by the pressurized air blowing pipe 11 so that the resin liquid 5 is connected to the connecting pipe. It is configured such that it can be discharged from the tip of the core 2 from 10 through the resin liquid supply hole 2a and the branch passage 2b in the core 2.

As described above, the reinforcing fiber 9 impregnated with the thermosetting resin liquid is supplied between the outer mold 1 and the core 2 inserted into the inlet 1a as described above. While being thermally cured by heating by the heating means 1c, the device 1
The inner layer resin liquid 5 discharged from the tip of the core 2 is press-fitted as described above into the inside while being drawn out along the forming surface on the inner side, and the heat from the heating means 1 c Receives the reaction heat of the thermosetting resin whose curing reaction is progressing on the outer layer side, and when a foaming resin liquid is used as the resin liquid 5 for the inner layer, foams immediately after being discharged from the core tip, When an internal space surrounded by the shape is filled and a thermosetting resin liquid containing bubbles or a porous material is used, the internal space is filled and heat is received from the outer peripheral side to cure.

Therefore, when a thermosetting resin is used as the resin for the inner layer, a heat-curing reaction is carried out after the core is discharged, and when a thermoplastic resin is used, it is cooled and solidified in the latter half of the outer mold. While pulling it out to the left in FIG. 1, the fiber reinforced resin 8a is enlarged as shown in FIG.
As an outer layer, and a resin (bubble or porous material) 8
The inner layer made of b is integrated and integrated, so that it is possible to continuously produce a lightweight multilayer resin product.

At this time, the filling and foaming of the inner layer resin liquid 5 as described above, and the curing reaction in the case of using a thermosetting resin, take place between the core 2 and the molding surface (inner surface) of the outer die 1. Since the curing reaction of the thermosetting resin impregnated in the reinforcing fibers 9 supplied and pulled out starts after the progress of the curing reaction, the fiber reinforced resin 8
There is no danger that the thickness of the outer layer constituted by a becomes uneven in the circumferential direction, and the bubbles (or the porous material) formed by the subsequent foaming and solidification, or the heating and curing after the discharge. The inner layer made of the material) containing resin 8b is firmly joined and integrated with the outer layer. FIG.
As described in (a), if the core 2 is provided with a water cooling mechanism or the like and is drawn while being cooled, the supply hole 2a and the branch path 2
In b, there is no danger that the foaming or heating and curing of the inner layer resin liquid 5 will occur and block the flow path, and the heating and foaming reaction or the heating and curing reaction will be more reliable than the curing of the thermosetting resin constituting the outer layer. It is preferable because it can be delayed.

When a resin liquid containing bubbles (or a porous material) is used as the resin liquid 4 for the inner layer, the viscosity is relatively high because the resin liquid contains bubbles (or a porous material). Volume expansion does not occur very much. On the other hand, when the foamable resin liquid is used, although its viscosity is relatively low, it foams by heating after being discharged from the tip of the core 2 and causes rapid volume expansion. Therefore, according to the viscosity of these resin liquids and the degree of volume expansion, by feeding them at an appropriate pressure while balancing the take-up speed, there is no gap inside the outer layer which is hardened on the inner surface side of the outer mold. Layer can be filled. In FIG. 1, pressurization using compressed air is used as a means for press-fitting these inner layer constituent resin liquids. However, the press-fitting method is not limited at all. For example, a liquid feed pump, a slurry pump, a screw type feeder and the like are known. Can be appropriately selected and adopted.

FIG. 1 shows a pultrusion molded product having a cross-sectional shape in which a bubble-containing resin is filled in a cylindrical outer layer, but the shape is not limited to the illustrated one. , Elliptical, rectangular, flat, corrugated, U-shaped, T-shaped, or other irregular cross-sectional shapes. 2 (A) to 2 (E) show specific examples of the cross-sectional shapes, and FIG.
2B is a rectangular shape, FIG. 2C is a flat plate shape, FIG.
FIG. 2D shows an example of a T-shape, and FIG. 2E shows an example of a double-sided wave shape. In order to obtain products with these cross-sectional shapes, an outer die having a molding surface shape corresponding to each shape is used, and a core having a shape corresponding to the cross-sectional shape of each bubble-containing resin layer is used. do it. Also, FIG.
As shown in (E), in order to form the bubble-containing resin layer in a divided state, a plurality of cores having a number and a shape corresponding to the number of divided formations are installed on the outer mold inlet side, and FIG. According to the method described above, the inner layer constituent resin liquid may be supplied through each core and foamed, hardened or solidified. Can be.

It is to be noted that the molding surface of the inner surface of the outer mold 1 and the outer peripheral surface of the core 2 are directly contacted with the thermosetting resin so that they are adhered in a drawing step, and there is a concern that the drawing cannot be carried out smoothly. However, if the inner surface of the outer die 1 and the outer surface of the core 2 are subjected to chrome plating or Teflon coating to enhance the releasability, such a concern is solved. It is also preferable to mix an internal mold release agent into the impregnating resin for the outer layer in order to smoothly perform the drawing.

In the present invention, the type of reinforcing fiber used as the reinforcing material of the outer layer is not limited at all, and may be glass fiber, carbon fiber, metal fiber, ceramic fiber (alumina, zirconia, silicon nitride, etc.), composite fiber Any fiber having a reinforcing action, such as various types of natural or synthetic organic fibers such as natural fibers and aramid fibers (boron-tungsten, silicon carbide-tungsten, etc.) may be used. The fibers can be properly used depending on the characteristics, and if necessary, two or more kinds of fibers can be used in combination. However, glass fibers and carbon fibers are the most common from the viewpoint of cost and reinforcing effect. These fibers are long fiber rovings, tapes, cloths,
It can be used as a mat or the like.

The type of the thermosetting resin impregnated in the reinforcing fibers is not particularly limited, but typical examples thereof include unsaturated polyester resins, epoxy resins, phenol resins, silicone resins, and vinyl esters. Based resins, aryl-based resins, melamine-based resins, urea-based resins, and the like are recommended as preferable ones.

On the other hand, as the resin constituting the inner layer, a resin containing bubbles (or a porous material) or a foamable resin is used as described above, and these resins may be either thermoplastic or thermosetting. It can be used, and as the thermosetting resin, a thermosetting resin as exemplified as the outer layer constituting resin is exemplified as preferable again, and as the thermoplastic resin, a polyolefin resin, a vinyl chloride resin, a polyamide resin is used. , A saturated polyester resin, an acrylic resin, a polyacetal resin, a polycarbonate resin, a polybutylene-terephthalate resin, a polyphenylene sulfide resin, and a polyether ether ketone resin. The choice between the thermosetting resin and the thermoplastic resin may be determined in consideration of the intended use and required characteristics of the FRP product, but the thermosetting resin is particularly preferred. The reason is that the use of a thermosetting resin makes it easier to obtain a resin with high strength, and since it has a low viscosity in the uncured state, it is easy to supply it as a resin for the inner layer, and by heating from the outer layer side This is because the hardening of the inner layer portion can be advanced in a short time.

When a resin containing air bubbles (or porous material) is used as the resin for forming the inner layer, examples of the air bubble forming material include porous inorganic fine particles such as shirasu, micro balloons (glass balloons, ceramic balloons, carbon balloons). Inorganic balloons such as styrene resin balloons, phenolic resin balloons, organic balloons such as acrylonitrile-methyl methacrylate copolymer balloons; and special micro-balloons obtained by applying a metal coating to an organic resin balloon). It is also possible to use a thermosetting resin liquid to cause air bubbles to be involved immediately before or during the press-fitting, and to cure with these air bubbles involved during the curing.

Examples of the foamable resin liquid include a polyurethane resin which itself generates a condensation polymerization reaction upon heating and hardening to generate air bubbles, and a resin liquid using an organic resin balloon filled with liquid hydrocarbon as a foaming agent. It is also effective to disperse the gas component therein and to heat the balloon after filling to make use of the volume expansion of the gas component enclosed therein to make the foam. In particular, in practicing the present invention, it is preferable to select and use a heat-foaming type foaming agent from the viewpoint of uniformly dispersing the foaming agent in the thermosetting resin and causing uniform foaming over the whole. .

If necessary, other additives such as a curing accelerator or inhibitor, an antioxidant, a stabilizer, a flame retardant, a viscosity modifier, and a coloring agent may be added to the outer layer resin liquid or the inner layer resin liquid. , Fillers and the like can be contained in appropriate amounts.

[0032]

According to the present invention, the outer layer is wrapped with a fiber reinforced resin layer, and the inside is filled with a resin containing air bubbles (or a porous material) to reduce the weight of the multilayer resin. Products can be efficiently and continuously produced on relatively short production lines. Moreover, when the apparatus or method of the present invention is employed, the filling, foaming, curing or solidification of the resin for the inner layer is performed after the fiber-reinforced resin layer constituting the outer layer is cured, or at least after the curing is advanced to some extent. Therefore, it is possible to stably obtain a high-quality and lightweight multilayer resin product without causing problems such as undesired non-uniformity and insufficient impregnation.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view illustrating an apparatus and a molding method of the present invention.

FIG. 2 is a cross-sectional view illustrating a lightweight multilayer resin product obtained by the present invention.

[Explanation of symbols]

 Reference Signs List 1 outer die 2 core 3a, 3b tooling guide 4 inner layer resin tank 5 inner layer resin liquid 6 outer layer impregnated resin tank 7 outer layer impregnated resin liquid 8 drawn product 9 reinforcing fiber

Claims (4)

[Claims] 1. A method for producing a multilayer resin product in which an inner layer is a bubble-containing resin layer and an outer layer is a fiber-reinforced thermosetting resin layer by a pultrusion molding method. While the composite material is cured in a state where the outer layer is regulated, the foamable resin liquid is supplied to the internal space surrounded by the outer layer, and the foamable resin liquid is solidified while foaming to fill the internal space. A continuous molding method for lightweight multi-layer resin products, characterized by drawing while pulling. 2. An inner layer comprising a resin layer containing air bubbles or a porous material,
In a method of manufacturing a multilayer resin product in which the outer layer is each formed of a fiber-reinforced thermosetting resin layer by a pultrusion method, a composite material of reinforcing fibers and a thermosetting resin is regulated in the outer layer shape. A lightweight composite characterized by supplying a resin liquid containing air bubbles or a porous material to an internal space surrounded by an outer layer thereof while curing, and curing or solidifying the resin liquid to fill the inner space and withdraw the resin liquid. A continuous molding method for resin products. 3. The resin layer containing an air bubble or a porous material as an inner layer,
A drawing-type continuous molding apparatus for producing a multilayer resin product in which the outer layer is composed of a fiber-reinforced thermosetting resin layer,
An outer mold with a heating mechanism that regulates and molds to the outer layer shape,
Inside the inlet portion of the outer mold, a core is provided with a gap corresponding to the outer layer shape between the inner surface of the outer mold and a resin material constituting the inner layer. A continuous molding apparatus for a multilayer resin product, comprising a supply means for supplying the resin to an inner space surrounded by an outer layer shape. 4. The continuous molding apparatus according to claim 3, wherein the core is provided with a cooling mechanism.